Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    The tree under which you sit : district-level management and leadership in maternal and newborn health policy implementation in the Greater Accra Region, Ghana
    Kwamie, A. - \ 2016
    Wageningen University. Promotor(en): Han van Dijk; I.A. Agyepong. - Wageningen : Wageningen University - ISBN 9789462576742 - 158
    health policy - birth - pregnancy - policy - management - administration - ghana - west africa - gezondheidsbeleid - geboorte - zwangerschap - beleid - bedrijfsvoering - bestuur - ghana - west-afrika

    Health system governance has to do with decision-making – who makes decisions, when, where, how and why. At the district level – the level of care which operationalises health policies – governance is critical, yet remains little understood. Governance has the ability to influence health system performance, and this is essential in maternal and newborn health, where timely decisions are required to support policy implementation. In this regard, district managers are particularly important. They are the link in the middle of the health system, connecting top-end policy formulation to bottom-end implementation. Their abilities to interpret, translate, support and challenge policy will have an effect on what gets operationalised. However, capacity weaknesses in district management and leadership are often cited as a factor in poor health system performance.

    This thesis seeks to deepen understandings of district-level management, leadership and decision-making for policy and programme management and implementation for maternal and newborn health. Within this, the thesis also seeks to understand the scope for change that an intervention to strengthen management and leadership capacities can bring.

    This thesis contributes to the applied field of health policy and systems research by drawing on policy implementation theory, organisational management theory and complexity theory as its theoretical basis. A realist approach methodology was undertaken to understand the contexts in which district managers are embedded, how this influences their decision-making, and what the effects of a managerial intervention are, given these contexts. The thesis followed an embedded case study flexible design. The first case study was an exploratory qualitative case study to understand how and why district managers make decisions in maternal and newborn health policy implementation. The second case study was an historical case study of district manager decision-space over time. The third case study was an explanatory qualitative case study of the management and leadership intervention. The final validation of our theorising throughout the cases was achieved through the administration of a questionnaire across all district health management teams of the Great Accra Region.

    This thesis demonstrates that district managers find themselves in contexts of strong hierarchical authority and resource uncertainty – in particular, lacking financial transparency. This promotes a management and leadership typology which attunes managers towards serving the health system bureaucracy, resulting in reduced district-level responsiveness to maternal and newborn health challenges. The outcome is that district manager decision-space is narrow surrounding resource allocation decisions, and this in turn affects local planning programming and management.

    The thesis further demonstrates that broader patterns of centralised governmental decision-making have affected the development of the district health system over time. Particularly, the sequencing of decentralisation processes has ensured that national-level decision-making has remained empowered in contrast to district-level decision-making. System fragmentation – through reduced Government of Ghana funds and increasingly verticalised donor funds – has also been a contributor. This accounts for the observed hierarchical authority and resource uncertainty which affects district managers. As a result of these contexts, this thesis also showed that an intervention to strengthen management and leadership capacities was limited in its sustainability.

    This thesis raises the issues of health system organisation as critical to the potential of district management and leadership effectiveness. It provides evidence that weaknesses in district management and leadership arise out of the organisational governance mismatches in autonomy and responsibility. It suggests that in strengthening management and leadership, approaches which seek to address organisational capacities, not only individual capacities, are needed to convey sustainable change. Advancements in this regard have the scope to improve district manager decision-making for maternal and newborn health policy and programme implementation in the future.

    Alternative testing strategies for predicting developmental toxicity of antifungal compound
    Li, H. - \ 2016
    Wageningen University. Promotor(en): Ivonne Rietjens; Bennard van Ravenzwaay, co-promotor(en): Jochem Louisse. - Wageningen : Wageningen University - ISBN 9789462576780 - 197
    toxicity - fetal development - transfer - infant development - adolescent development - child development - pregnancy - in vivo experimentation - modeling - placenta - in vitro - risk assessment - tebuconazole - conazole fungicides - antifungal agents - alternative methods - toxiciteit - foetale ontwikkeling - overdracht - zuigelingenontwikkeling - adolescentenontwikkeling - kinderontwikkeling - zwangerschap - in vivo experimenten - modelleren - placenta - in vitro - risicoschatting - tebuconazool - conazoolfungiciden - antimycotica - alternatieve methoden

    Determination of safe human exposure levels of chemicals in toxicological risk assessments largely relies on animal toxicity data. In these toxicity studies, the highest number of animals are used for reproductive and developmental toxicity testing. Because of economic and ethical reasons, there is large interest in the development of in vitro and/or in silico test systems as alternatives for the animal studies. The aim of the present thesis was to evaluate the applicability of combined in vitro approaches taking toxicokinetic and toxicodynamic aspects into account, as well as of an integrated in vitro and in silico approach for prediction of developmental toxicity using a series of antifungal compounds as the model compounds.

    Transplacental transfer of compounds is highly likely to play an important role in developmental toxicity, so we developed and validated an in vitro placental barrier model using BeWo b30 cells to predict placental transfer. Then we investigated the applicability of the ES-D3 cell differentiation assay combined with the in vitro BeWo transport model to predict the relative in vivo developmental toxicity potencies of two sets of selected antifungal compounds. The data obtained show that the combined in vitro approach provided a correct prediction for the relative in vivo developmental toxicity, whereas the ES-D3 cell differentiation assay as stand-alone did not. In order to detect specific structural alterations induced by chemicals, we investigated the applicability of the ex ovo assay of chicken embryos to predict the specific alterations induced by the antifungal compounds. Data revealed that the ex ovo assay of chicken embryos is able to assess the teratogenic potential of antifungal compounds, and, when combined with the in vitro BeWo transport model, is able to better predict relative in vivo prenatal developmental toxicity potencies.

    Subsequently, we translated in vitro concentration–response data of the antifungal compound tebuconazole, obtained in the ES-D3 cell differentiation assay and the ex ovo assay of chicken embryos, into predicted in vivo dose–response data using physiologically based kinetic (PBK) modelling-facilitated reverse dosimetry. The results show that the BMD10 values from predicted dose–response data from both assays are in concordance with BMD10 values derived from in vivo data (within 5-fold difference). This revealed that PBK modeling is a promising tool to predict in vivo dose-response curves based on the results of in vitro toxicity assays, and may therefore be used to set a point of departure for deriving safe exposure limits in risk assessment.

    It is concluded the combined in vitro approaches and the integrated in vitro-in silico approaches appear to be promising for the screening and prioritization of chemicals and to provide reference values, such as BMD10 values, without using animals, therefore contributing to the 3R principle of animal testing.

    Human nutrition : a crunchy bite
    Kok, F.J. - \ 2015
    Wageningen : Wageningen University - ISBN 9789462573703 - 28
    obesity - malnutrition - infant nutrition - nutrition and health - nutrition research - human nutrition research - vitamins - aging - pregnancy - abdominal fat - body fat - obesitas - slechte voeding - zuigelingenvoeding - voeding en gezondheid - voedingsonderzoek - voedingsonderzoek bij de mens - vitaminen - verouderen - zwangerschap - buikvet - lichaamsvet
    Farewell address upon retiring as Professor of Nutrition and Health
    at Wageningen University on 15 October 2015
    Kan panda zwangerschap faken voor luxe fruithapjes?
    Teerds, Katja - \ 2015
    Panda - zwangerschap - Teerds - Hormoonproductie - Schijnzwangerschap
    Effect of iodine supplementation in Indian pregnant women on maternal and newborn thyroid function and cognitive development
    Jaikrishna, N. - \ 2015
    Wageningen University. Promotor(en): Michael Zimmermann, co-promotor(en): Alida Melse-Boonstra; K Srinivasan. - Wageningen : Wageningen University - ISBN 9789462573338 - 244
    jodium - maternale voeding - zwangerschap - voeding - hypothyreoïdie - schildklierziekten - schildklierwerking - jodiumhoudend zout - minerale supplementen - kenvermogen - cognitieve ontwikkeling - mineraaltekorten - voedingsstoffentekorten - iodine - maternal nutrition - pregnancy - nutrition - hypothyroidism - thyroid diseases - thyroid function - iodized salt - mineral supplements - cognition - cognitive development - mineral deficiencies - nutrient deficiencies

    ABSTRACT

    Background: Iodine is a key nutrient in neurodevelopment, and the fetus is entirely dependent on the iodine intake of the mother to fulfill this important requirement for proper brain function. While this is clearly known, it is uncertain if maternal iodine nutrition should be monitored separately against what is in current practice in public health programs to control iodine deficiency. Also, it is unclear whether it is beneficial to supplement pregnant women with iodine in mild-to moderately iodine deficient and also iodine sufficient areas. Finally, the role of thyroid dysfunction in depression during pregnancy is uncertain.

    Objectives: 1) to determine whether iodine supplementation to pregnant women improves maternal and newborn thyroid function, pregnancy outcome, birth weight, infant growth and cognitive performance; 2) to assess iodine intake and potential determinants of intake, in pregnant women and their children who were sharing all meals; 3) to measure thyroid status during pregnancy and assess potential determinants of maternal thyroid function including iodine status, thyroid autoimmunity, body weight and anemia; 4) to assess the association of maternal depression, and thyroid function during pregnancy.

    Methods: 1) In a randomized placebo controlled trial (RCT), the MITCH (Maternal Iodine Supplementation and its Effects on Thyroid function and CHild Development) study, pregnant women, gestational age ≤14 weeks, in Bangalore, India, were randomized to receive either a daily supplement of 200 µg oral iodine or placebo from enrolment until delivery. Women were followed through delivery, and then with postnatal follow-up of their infants at 6 weeks, 1 and 2 year. Early neonatal development was assessed using the Neonatal Behavioral Assessment Scale (NBAS) at 6 weeks of age; neurocognitive assessment was done using the Bayley Scales of Infant Development (BSID III) at 1 and 2 years, and BRIEF-P (Behavior Rating Inventory of Executive Function) at 2 years; 2) A cross-sectional study comparing iodine status of pregnant women and their children, who were sharing all meals in Bangalore, India; 3) A cross-sectional study among 334 pregnant women ≤14 weeks of gestation, in Bangalore, India, who were screened for the RCT; 4) Secondary analysis of the longitudinal data on 318 pregnant women in the RCT.

    Results: 1) In the RCT, there were no significant differences between groups in maternal thyroid function tests or thyroid volume during gestation. The prevalence of thyroid dysfunction or anti-TPO antibodies did not differ significantly during gestation and postpartum. Postpartum, there were no significant differences between the maternal and infant groups in thyroid function, birth outcomes or UIC. Neonates whose mothers received iodine supplementation during pregnancy had better orientation scores at 6 weeks of age and lower scores of inhibition suggesting better executive function at 2 years of age although neurocognitive development on the BSID III were not significantly different between groups; 2) In the pilot study, a) median UIC in pregnant women was 172 µg/L, b) the median UIC was >150 µg/L in all trimesters and c) thyroid size was not significantly different across trimesters; the median UIC in children was 220µg/L, indicating ‘more than adequate’ iodine intake at this age. Median UIC was significantly higher in children than in their mothers (p=0.008). 3) In the cross-sectional study, 21% women were vegetarian, 19% were anemic and 23% were overweight or obese. Iodized salt was used by 98% of women and they were iodine sufficient, median UIC was 184.2 µg/L and all had normal thyroid volume. However, 18% of women had thyroid insufficiency: 3.7% had overt hypothyroidism (83% with positive TPO-Ab), 9.2% had subclinical hypothyroidism and 5.2% had hypothyroxinemia. Women consuming vegetarian diets did not have significantly lower iodine intakes or higher risk of hypothyroidism than those consuming mixed diets, but overweight/obesity and anemia predicted thyroid insufficiency; 4) In the longitudinal study, there was no significant difference in depressive symptoms between the iodine intervention and placebo groups. Women with depressive symptoms had significantly lower serum TSH compared to women without depressive symptoms in the first trimester. Pregnant women with prenatal depressive symptoms had a significantly higher number of medical symptoms.

    Conclusion: 1) Iodine supplementation in mildly iodine deficient and in iodine sufficient pregnant women was well-accepted and safe and did not increase the risk of excess iodine intake, hyper- or hypothyroidism, or thyroid autoimmunity. Though there were no significant effects of iodine supplementation on neonatal and maternal thyroid function and birth outcomes, there were modest effects on neurocognitive development of children as assessed by executive function of children at 2 years. Thus, additional follow-up of these children for neurocognitive testing at a later age when development and cognitive testing is more reliable would provide valuable add on information; 2) The iodized salt program in Bangalore, India was providing adequate iodine to women throughout pregnancy, at the expense of higher iodine intake in their children, suggesting that the current WHO/UNICEF/ICCIDD cut-off for median UIC in children indicating more-than-adequate intake may need to be reconsidered; 3) Despite iodine sufficiency, many pregnant women had thyroid insufficiency predicted by low hemoglobin and higher BMI. The prevalence of overt hypothyroidism was >5-fold higher than reported in other iodine-sufficient populations of pregnant women, thus, screening of maternal thyroid function should be considered in antenatal care at hospitals in Bangalore, India; 4) Although iodine supplementation did not affect maternal depression, we highlighted the need for systemic screening for prenatal depression during antenatal visits as it is an independent risk factor for later development of clinical depression

    Gestational diabetes mellitus in Tanzania : public health perspectives
    Mwanri, A.W. - \ 2015
    Wageningen University. Promotor(en): Edith Feskens, co-promotor(en): J.L. Kinabo; K. Ramaiya. - Wageningen : Wageningen University - ISBN 9789462572645 - 202
    diabetes mellitus - voedselintolerantie - zwangerschap - zwangerschapscomplicaties - obesitas - koolhydraten - diabetes mellitus - food intolerance - pregnancy - pregnancy complications - obesity - carbohydrates

    Gestational diabetes mellitus in Tanzania – public health perspectives

    Abstract

    Background: Gestational diabetes mellitus (GDM) is defined as carbohydrate intolerance resulting in hyperglycaemia of variable severity with onset or first recognition during pregnancy. Women with GDM are at increased risk for preeclampsia during pregnancy and for delivery complications. In most cases GDM ends after pregnancy, but it increases the risk for future type 2 diabetes, and cardiovascular diseases, to both the mother and the child. With the current increase in prevalence of overweight/obesity and type 2 diabetes in Tanzania and other Sub Saharan African countries, it is possible that GDM may exist and may be on the rise.

    Methods: A cross-sectional survey was done in 2011 through 2013 where 910 women in Tanzania (609 from urban, 301 from rural areas) were studied during their usual antenatal clinic visits. Weight, height, mid upper arm circumference (MUAC), blood pressure and haemoglobin levels were measured by a trained technician. Blood glucose was measured at fasting and at two hours after 75 g oral glucose tolerance test. Women were classified as having GDM using WHO 1999 criteria. Sociodemographic information was collected through face-to-face interviews using structured questionnaire or retrieved from the antenatal clinic card. Dietary intake data was collected using 24-hour recall interview and foods were categorised into groups based on dietary diversity. The international physical activity questionnaire (IPAQ) was used to assess activities in the past one week. Information on birth outcome was obtained from 466 urban mothers (response rate 77%) through telephone interviews. To estimate the burden of GDM in the region, we additionally conducted a systematic search of published literature on the prevalence and risk factors of GDM in Sub Saharan Africa. Out of the 22 reviewed studies, 15 studies graded as having low or moderate risk of bias were included in a meta-regression analysis. Finally, a review of literature regarding the health system and antenatal care was done and supported by a survey to assess antenatal care services in 24 health facilities that provide maternal and childcare services in Dar es Salaam region.

    Results: The prevalence of GDM was much higher among women residing in the urban (8.4%) compared to those in the rural areas (1.0%), which was much higher compared to 0% reported in the 1990s. Prevalence of GDM was higher for women who had a previous stillbirth, family history of type 2 diabetes and MUAC ≥28 cm, and lower for women with normal haemoglobin concentrations compared to those with anaemia. Likewise, the prevalence of hypertension disorders of pregnancy (HDP) was higher in urban (8.9%) compared to rural areas (5.3%). Risk factors for HDP in urban women were advanced maternal age, high MUAC, gestional age and being HIV positive, and in rural women age and gestational age.

    We reviewed 22 studies conducted in six out of the 47 Sub saharan African countries. Heterogeneity between the studies was high and it could not be significantly explained by study setting, population, diagnostic criteria, or the year the study was done. Nevertheless, a relatively higher prevalence was observed in studies done after the year 2000, when women at risk were selected and when more current diagnostic criteria were used. The prevalence was up to about 14.0% when women with at least one risk factor were studied. In Dar es Salaam women, despite a high prevalence of anemia and HIV, the prevalence of macrosomia was higher (5.9%) compared to the prevalence of low birth weight (3.6%). Presence of GDM (OR 3.46, 95% CI 1.01-11.85) and birth weight of the previous child (OR 2.42, 95% CI 1.17-4.99) were the main predictors of macrosomia and HDP (OR 3.75, 95% CI 1.11-12.68) was the main predictor of low birth weight. Although glucose testing in urine appeared to be universally done in the urban setting, the sensitivity of this test for detection of GDM is low. Therefore selective blood glucose testing should be implemented and HIV testing and counselling may be used as an entry point.

    Conclusions: The prevalence of GDM and HDP was higher in the urban compared to the rural areas in Tanzania, indicating an increasing in women who are at risk for delivery complications, poor pregnancy outcomes, type 2 diabetes and cardiovascular diseases in later life. The risk factors observed can be used to identify risk groups for screening and as target for prevention interventions. To inform policy makers and for better health care planning, further studies on the costs for blood glucose testing during the usual antenatal clinic visits and on the management of women with GDM are warranted.

    Een nieuwe rol voor de verloskundige : onderzoek naar kansen en belemmeringen voor de Wageningse verloskundigen
    Wagemakers, A. ; Vaandrager, L. - \ 2015
    Wageningen : Wetenschapswinkel (Rapport / Wetenschapswinkel Wageningen UR 309) - 63
    verloskundigen - seksuele voorlichting - seksuele gezondheid - lagere klassen - arbeidersklassen - voorbehoedsmiddelen - orale voorbehoedsmiddelen - onderwijs - zwangerschap - midwives - sex education - sexual health - lower classes - working classes - contraceptives - oral contraceptives - education - pregnancy
    Effects of iodine supplementation in mild-to-moderately iodine-deficient pregnant women on thyroid function, pregnancy outcomes and newborn development in Thailand
    Gowachirapant, S. - \ 2014
    Wageningen University. Promotor(en): Michael Zimmermann, co-promotor(en): Alida Melse-Boonstra; P. Winichagoon. - Wageningen : Wageningen University - ISBN 9789462570290 - 162
    jodium - voedingstoestand - sporenelementtekorten - minerale supplementen - zwangerschap - schildklierwerking - zuigelingenontwikkeling - thailand - iodine - nutritional state - trace element deficiencies - mineral supplements - pregnancy - thyroid function - infant development - thailand

    Background: Iodine deficiency (ID) during pregnancy has been recognized as a major cause of hypothyroidism and adverse health consequences in both mothers and children. Although urinary iodine concentration (UIC) in school-aged children is recommended as an indicator to assess ID in the general population, it may not be a good surrogate for directly assessing iodine status in pregnant women. Iodine supplementation of mildly iodine-deficient pregnant women has been recommended worldwide; however, long-term benefit and safety of iodine supplementation in this group is uncertain. Finally, pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) may negatively affect thyroid function and pregnancy outcomes.

    Objectives: 1) to measure UIC in pairs of pregnant women and their school-aged children living in the same household; 2) to investigate the effects of iodine supplementation on maternal thyroid function, pregnancy and birth outcomes, and newborn development; 3) to evaluate the association between pre-pregnancy BMI and GWG with thyroid function and pregnancy outcomes.

    Methods: 1) In a cross-sectional pilot study, UIC was measured in spot urine samples from pairs (n=302) of healthy pregnant mothers and their school-aged children in Bangkok; 2) Arandomized controlled trial was conducted with 200 µg iodine per day or placebo given to mildly ID pregnant Thai women from <14 weeks to term. Anthropometrics, maternal thyroid function, UIC and thyroid volume were measured at baseline, 2ndand 3rdtrimester, at delivery and 6-week postpartum. Birth outcomes were collected from hospital records. Neonatal thyroid function, UIC and thyroid volume were measured at delivery and 6 weeks after birth. The Neonatal Behavioral Assessment Scales (NBAS) was used to assess newborn development.

    Results: 1) In the pilot study, median UIC in the pregnant women was 108 (11–558) µg/L and was lower than UIC in their school-aged children [200 (25–835) µg/L] (P<0.001); 2) In the RCT, medianUIC increased significantly from baseline in both groups, and the increase was higher in the iodine group (p<0.001). At 30 weeks of gestation, only 2% of the women in the placebo group and 7% in the iodine group reported a median UIC >500 µg/L. Maternal thyroid function, thyroid volume and the prevalence of all thyroid dysfunction subtypes did not differ significantly between treatment groups during the study (p>0.05). At 6-week postpartum, the prevalence of postpartum thyroiditis (hyperthyroidism) was significantly lower in the iodine group (3%) as compared to the placebo group (9%) (OR: 95%CI, 0.17: 0.04-0.70). There were no significant differences between newborn groups in thyroid function, thyroid volume, birth characteristics, UIC and NBAS score (p>0.05); 3) Pre-pregnancy BMI was a negative predictor of free thyroxine (fT4) (β=-0.20, P<0.001) in early gestation (<14 weeks). Compared to normal weight women, the prevalence ratio (95% CI) of a low fT4 in overweight women was 3.64 (2.08–6.37) (P<0.01). In addition, secondary data analysis showed that overweight women had an 11-fold higher risk of delivering a large for gestational age infant compared to normal weight women, while women who had excessive GWG were 5.6 times more likely to deliver a macrosomic infant compared to women with normal GWG.

    Conclusion: 1) UIC in school-aged children should not be used as a surrogate for monitoring iodine status in pregnancy; 2) iodine supplementation (200 µg/d) in mildly iodine-deficient pregnant Thai women was effective in increasing iodine intakes into the adequate range but had no benefit on antenatal maternal thyroid function or newborn outcomes out to 6 weeks; however, it significantly reduced the risk of maternal postpartum thyroid dysfunction; 3) excess maternal body weight both before and during pregnancy may have adverse impacts on maternal thyroid function as well as birth weight. Therefore, maintaining normal body weight before and throughout pregnancy should be recommended.

    Safety and efficacy of iron supplementation in pregnant Kenyan women
    Mwangi, M.N. - \ 2014
    Wageningen University. Promotor(en): Huub Savelkoul; A.M. Prentice, co-promotor(en): Hans Verhoef. - Wageningen : Wageningen University - ISBN 9789461739209 - 220
    ijzer - minerale supplementen - veiligheid - risicoschatting - werkzaamheid - zwangerschap - kenya - iron - mineral supplements - safety - risk assessment - efficacy - pregnancy - kenya

    Since the British doctor Ronald Ross received the 1902 Nobel Prize in medicine for his work on malaria, more people have died from the disease than all world wars combined. This is in spite of the fact that the French chemists Pierre Joseph Pelletier and Joseph Bienaimé Caventou made quinine available from as early as 1820. According to the World Health Organisation (WHO), there were about 219 million cases of malaria in 2010 and an estimated 660,000 deaths majority of which (80% of cases and 90% of deaths) were in Africa.

    Of almost two billion people who are anaemic globally, 41.8% are pregnant women. Iron supplements are used to prevent anaemia. There are concerns that iron given in high doses may increase malaria rates. Uncertainties regarding the safety of iron supplementation in malaria endemic regions were propelled by a randomized controlled trial that evaluated the effects of iron and folic acid supplementation in 32,155 children in Pemba, Tanzania. This study found that children who received iron and folic acid supplements were more likely to die or to need hospitalisation for an adverse event. At the same time, malaria is known to exacerbate anaemia; an almost inevitable consequence of malarial infection. As such, the safety of daily oral use of iron supplements by pregnant women, as a public health intervention is still not clearly established; at least not until publication of our main findings.

    This thesis assessed the effects of iron supplementation on safety indicators, and on iron status, in pregnant women and their neonates. Several preparatory activities were carried out, including a census of the population in the study area and a pilot study to check the operability of the study protocols. A main study was designed with the hypothesis that consumption of food products fortified with iron combined with intake of iron supplements especially in pregnancy, would be detrimental to the health of pregnant women and their neonates.

    The objectives of the study were: 1) to compare the presence of malarial infection in parturient women who received a combination of iron-fortified foods with iron supplements versus iron-fortified foods only; 2) to assess intervention effects on the maternal prevalence of iron deficiency anaemia at 1 month after delivery; 3) to assess intervention effects on neonatal iron stores at 1 month of age; 4) to assess the diagnostic utility of Zinc protoporphyrin (ZPP) in diagnosing iron deficiency in malaria endemic regions; 5) to identify baseline factors that are prognostic for the Non-Transferrin Bound Iron (NTBI) response to consumption of a single iron supplement; 6) to determine the factors that predict Plasmodium infection in pregnancy; 7) to identify factors associated with birth weight; 8) to develop a methodology to predict cases of low birth weight, using a single prognostic score that is based on prognostic variables collected at the second trimester of pregnancy; and 9) to develop methods for community-based flour fortification with iron.

    Most countries have enacted, or are in the process of enacting legislation for mandatory fortification of flour with iron. Thus pregnant women may receive iron from fortified foods and from universal iron supplementation programmes. This thesis provides answers to pertinent questions regarding the safety and efficacy of iron supplementation by comparing daily high-dose iron (i.e. iron-fortified foods plus iron supplements) versus low-dose iron (i.e. iron-fortified foods only) during pregnancy. The main outcome measure was the presence of maternal Plasmodium infection at birth, regardless of species. Chapter 1 is a detailed introduction of the background to the study and the design of the study.

    This thesis presents concrete evidence that iron supplementation to pregnant women in a highly malaria endemic region does not result in increased risk of malarial infection; percent difference (95%CI) = 0.0% (─9.3% to 9.3%). Programme implementers and governments in malaria endemic regions should not be held back by previous recommendations that cautioned against issuing iron supplements to pregnant women. In light of these findings, there is no need to first screen for malaria before giving iron supplements.

    Iron supplementation had major benefits for mothers and their neonates (chapter 2). The findings reported in this thesis showed a mean increase in birth weight of 143 g relative to the low-dose iron group. The effects of iron were influenced by the participants initial iron status. Correction of iron deficiency increased birth weight by 249 g, even though we cannot exclude the possibility that this may have increased malarial infection by 10%. There was no evidence that effects of iron on birth weight were influenced by intermittent preventive treatment against malaria. Iron supplementation also increased fetal growth by 0.27 SD, 95%CI: (0.04 to 0.50) probably as a result of gains in length and weight for gestation age.

    We also showed improved neonatal iron stores one month post-partum as indicated by a 17.1 % (95% CI: 2.0% to 34.3%) increase in plasma ferritin concentration in neonates of mothers who received high-dose iron compared to those who received low-dose iron. This provides more impetus to the need to offer iron supplements to pregnant women with the aim of boosting infant iron stores (chapter 2).

    ZPP was found to be of unreliable diagnostic utility when discriminating between pregnant women with and without iron deficiency in regions where chronic diseases are prevalent (chapter 3). The current conventional cut off points for whole blood ZPP e.g. >70 μmol/mol heme, can result in gross estimates of the prevalence of iron deficiency especially if the true prevalence is low.

    The appearance of non-transferrin bound iron (NTBI) in circulation after oral ingestion of iron supplements has been thought to aid the growth and multiplication of Plasmodium parasites thereby increasing malaria induced morbidity and mortality. We did not observe any increase in NTBI concentrations three hours after oral ingestion of 60 mg of ferrous fumarate (Chapter 4). We cannot exclude the possibility that iron supplementation leads to NTBI production when supplements are not consumed with food, because the lunch meal consumed by majority of our participants during the 3-hour waiting period probably contained natural compounds (phytates) that may have limited an NTBI response.

    In chapter 5 of this thesis, we aimed to develop a field friendly tool that can be used to predict asymptomatic Plasmodium infection. This was motivated by the fact that most point-of-care dipstick tests used to detect Plasmodium infection are not able to detect 100% of all the infection present yet asymptomatic infections are increasingly associated with adverse maternal and neonatal outcomes. Although many likely predictive factors were assessed individually or in combination with others, we did not succeed in developing a reliable tool that is easy to apply in resource-poor malaria endemic settings.

    In Chapter 6, we aimed to identify factors associated with birth weight and to develop a methodology to predict cases of low birth weight using a single prognostic score that is based on prognostic variables collected at the second trimester of pregnancy. Factors that were found to be independently associated with reduced birth weight were being never married, inflammation, being a girl, and iron deficiency. Being overweight was associated with increased birth weight. The results indicate that we can use variables collected rapidly and at relatively low cost and ease to identify with fair accuracy women in the second trimester of pregnancy who are at high risk of giving birth to a neonate with low birth weight.

    The various aspects of the work presented in this thesis including the implications for policy makers are discussed in chapter 7. For policy makers, the findings of this thesis are a welcome relief. The findings therein eliminate all doubt that has hitherto been associated with antenatal iron supplementation in malaria endemic areas. Most countries already have iron supplementation policies that are well aligned to the World Health Organisation policies. Efforts to widen the coverage of antenatal iron supplementation especially in malaria endemic regions should be urgently scaled up. However, the evidence provided in this thesis is only applicable to pregnant women and cannot be extrapolated to children in malaria endemic regions. For this population, the current WHO policy must be used thus before iron supplementation, children must first be screened for malaria.

    Although this thesis provides answers to key scientific questions that have hitherto baffled the scientific community, there are still research questions that can be clarified further. The effects of a high iron dose in pregnancy (as per national and international guidelines, the daily supplementation dose for pregnant women should be doubled to 120 mg iron if they are anaemic or if 6 months duration cannot be achieved in pregnancy (Chapter 2)) on maternal and neonatal outcomes need to be elucidated. Further research is needed in order to describe fully, the NTBI response to consumption different types and amounts of oral iron supplements. There is urgent need for diagnostic tools that can be used in resource-poor settings to diagnose asymptomatic infections. Further research in children is needed to provide evidence of the safety and efficacy of iron supplementation in malaria endemic regions and to assess the diagnostic performance of zinc protoporphyrin in children. In addition, since our studies suggest that screening based on Hb concentration as now practiced in many countries, is inaccurate in discriminating between women at high and low risk of delivering neonates with low birth weight, further studies are needed to identify appropriate markers and cut-off points that are suited to this purpose.

    In conclusion, this thesis has shown that there is no evidence that antenatal iron supplementation increases Plasmodium infection. Antenatal iron supplementation leads to large improvements in birth weight, fetal growth and infant iron stores, with potentially immense benefits for infant survival and health that should outweigh any possible concerns about risks of malaria. Epidemiological calculations indicate that if our results are applied to all women in developing countries in order to eliminate iron deficiency, we could avoid 3 million births with low birth weight annually and save the lives of more than half a million neonates. Scaling up universal iron supplementation in pregnancy in developing countries will generate major public health gains.

    Vroege detectie van dracht bij koeien door Proteomics Biomerkers in melk = Early pregnancy detection using proteomics biomarkers in milk
    Pas, M.F.W. te; Kruijt, L. ; Wit, A.A.C. de; Hulsegge, B. ; Riel, J.W. van; Heeres-van der Tol, J.J. ; Sulkers, H. ; Woelders, H. - \ 2014
    Lelystad : Wageningen UR Livestock Research (Rapport / Wageningen UR Livestock Research nr. 747) - 10
    melkkoeien - zwangerschap - eiwitexpressieanalyse - merkers - melkproductie - melkveehouderij - rundveehouderij - productiebeperkingen - optimalisatie - voortplantingsefficiëntie - dairy cows - pregnancy - proteomics - markers - milk production - dairy farming - cattle husbandry - production restrictions - optimization - reproductive efficiency
    The aim of this study is to develop an accurate, fast, cheap, and reliable test to detect pregnancy before day 35 on the basis of markers in milk. The ultimate goal is to have a method that can be implemented in a practical setting.
    Control of Pig Reproduction IX
    Rodriguez-Martinez, H. ; Soede, N.M. ; Flowers, W.L. - \ 2013
    Leicestershire, United Kingdom : Context Products Ltd (Society of Reproduction and Fertility volume 68) - ISBN 9781899043484 - 345
    varkens - geslachtelijke voortplanting - gameten - embryo's - kunstmatige inseminatie - embryotransplantatie - zwangerschap - partus - pasgeborenen - biggen - overleving - biotechnologie - metabolomica - eiwitexpressieanalyse - kunstmatige selectie - pigs - sexual reproduction - gametes - embryos - artificial insemination - embryo transfer - pregnancy - parturition - neonates - piglets - survival - biotechnology - metabolomics - proteomics - artificial selection
    Micronutrient status and effects of supplementation in anemic pregnant women in China
    Ma, A. - \ 2013
    Wageningen University. Promotor(en): Evert Schouten; Frans Kok. - S.l. : s.n. - ISBN 9789461734938 - 148
    ijzergebrekanemie - zwangerschap - vitaminetoevoegingen - minerale supplementen - voedingstoestand - china - iron deficiency anaemia - pregnancy - vitamin supplements - mineral supplements - nutritional state - china

    Background

    Iron deficiency anemia (IDA) is a major nutrition related problem in China, especially affecting pregnant women,like in most developing countries. Deficiencies of vitamins also play an important role, such that iron, retinol and riboflavin deficiencies tend to coexist in anemic pregnant women. However, vitamin and/or mineral supplements are not routinely used by pregnant women at or below low income levels. Besides being an essential trace element, iron plays a central role in oxygen radical generation, whereas susceptibility during pregnancy is elevated. There is evidence that both iron deficiency and excess may result in free radical damage.

    Objectives

    Based on this background, objectives of this thesis were to investigate the current prevalence of anemia among pregnant women in different sites of China, and todescribe the micronutrient status of anemic and non-anemic pregnant women in China. In addition, in anemic pregnant women, the effect of retinol and riboflavin supplementation on top of iron plus folic acid on anemia and changes in hematological status wasassessed. Also oxidative stress and erythrocyte membrane fluidity were evaluated. Finally, we compared the effect of sodium iron ethylenediaminetetraacetate (NaFeEDTA) and ferrous sulfate on hemoglobin (Hb), iron bioavailability and oxidative stress.

    Subjects and Methods

    A total of 6413 women in their third trimester of pregnancy were recruited from five rural areas in China (years 2000~2003) for screening anemia or iron deficiency. A random subset was selected for measuring micronutrient status. In three supplementation trials, effects of iron, folic acid, retinol and riboflavin were assessed among anemic pregnant women. Outcomes included hematological status, micronutrient status and parameters of oxidative stress. Samples of fasting blood were collected from subjects before and at the end of the interventions for measurements.

    Results

    The overall prevalence of anemia was 58.6%, ranging between 48.1%~70.5% in the five areas. Serum concentrations of micronutrients were significantly lower in anemic women than non-anemic women. After the 2-mo intervention, the increase of Hb concentration in the group, supplemented with iron and folic acid combined with retinol and riboflavin, was 5.4g/L greater than in the group with iron and folic acid only (p<0.001). The reductions in the prevalence of anemia (Hb<110g/L) and iron deficiency anemia were significantly greater in the groups supplemented with retinol and/or riboflavin than in the iron and folic acidgroup. Riboflavin and/or retinol supplementation significantly improved gastrointestinal symptoms and well-being. In addition, supplementation of iron combined with retinol and riboflavin significantly decreased levels of serum malondialdehyde, and increased activities of glutathione peroxidase and erythrocyte membrane fluidity as well. NaFeEDTA supplementation showed superior effectiveness.

    Conclusion and recommendations

    Deficiency of iron and micronutrients in combination appears to contribute to the high prevalence of anemia in pregnant women in rural China. Supplementation with iron, particularly in combination with vitamins improved hematologic status as well as oxidative stress. NaFeEDTA performed better than ferrous sulfate. Multi-micronutrient supplementation may be worthwhile for pregnant women in rural China. Further studies on food-based or supplement-based approaches are warranted to decrease anemia of Chinese pregnant women in the third trimester.

    Pregnancy test via milk
    Siemes, H. ; Woelders, H. - \ 2011
    Veepro Magazine 79 (2011). - p. 8 - 8.
    melkveehouderij - zwangerschap - tests - melkeiwitten - progesteron - dairy farming - pregnancy - tests - milk proteins - progesterone
    Determining a pregnancy through the milk. Wageningen University is researching the possibilities. The first steps have been taken. Researchers have identified five milk proteins that release a signal of a pregnancy. A pregnancy test via the milk comes within sight.
    Ruwvoer voor dragende zeugen
    Bikker, P. - \ 2011
    BioKennis bericht Varkensvlees 2011 (2011)18. - 4
    zeugen - zwangerschap - zeugenvoeding - varkensvoeding - ruwvoer (roughage) - kuilvoer - varkenshouderij - biologische landbouw - voeropname - sows - pregnancy - sow feeding - pig feeding - roughage - silage - pig farming - organic farming - feed intake
    Kan ruwvoer een deel van het krachtvoer voor dragende zeugen verantwoord vervangen? Dat is de centrale vraag van het onderzoeksproject ‘Gras- en mengkuilen voor drachtige zeugen’ van Wageningen UR Livestock Research. Het lijkt mogelijk om 1 EW (Energie Waarde) uit krachtvoer door graskuil of 1,5 EW uit krachtvoer door mengkuil te vervangen in het voer van dragende zeugen. Daarbij moet de variatie in ruwvoeropname tussen zeugen worden beperkt zodat ook jonge en ranglage dieren voldoende ruwvoer en energie opnemen.
    Opname van gras- en mengkuil door dragende biologische zeugen
    Bikker, P. ; Peet-Schwering, C.M.C. van der; Binnendijk, G.P. - \ 2011
    Lelystad : Wageningen UR Livestock Research (Rapport / Wageningen UR Livestock Research 439) - 33
    biologische landbouw - zeugen - zwangerschap - voersamenstelling - graskuilvoer - kuilvoer - gerst - maïs - voeropname - organic farming - sows - pregnancy - feed formulation - grass silage - silage - barley - maize - feed intake
    In this study it was determined whether the concentrate allowance of pregnant sows can be partly replaced by the supply of grass silage of grass silage mixed with barley or CCM.
    Verteerbaarheid en voederwaarde van diverse kwaliteiten graskuil en van CCM bij biologische zeugen = Digestibility and nutritive value of several qualities of grass silage and of CCM in organic housed gestating sows
    Peet-Schwering, C.M.C. van der; Binnendijk, G.P. ; Diepen, J.T.M. van - \ 2010
    Lelystad : Wageningen UR Livestock Research (Rapport / Wageningen UR Livestock Research 342) - 16
    zeugen - zwangerschap - biologische landbouw - voersamenstelling - graskuilvoer - kuilvoer - droge stof - energetische waarde - varkenshouderij - sows - pregnancy - organic farming - feed formulation - grass silage - silage - dry matter - energy value - pig farming
    The chemical composition, digestibility and energy value of five qualities of grass silage and of CCM (Corn cob mix) were investigated in organic housed gestating sows. The dry matter content of the five grass silages varied between 21.3 and 24.9%. The energy value per kg dry matter varied between 0.78 and 0.95. Energy value per kg dry matter and daily dry matter intake were highest in grass silage with a yield of 2.2 ton dry matter per ha and lowest in grass silage with a yield of 5.0 ton dry matter per ha.
    Lactational oestrus in sows : follicle growth, hormone profiles and early pregnancy in sows subjected to Intermittent Suckling
    Gerritsen, R. - \ 2008
    Wageningen University. Promotor(en): Bas Kemp, co-promotor(en): P. Langendijk; Nicoline Nieuwenhuizen-Soede. - [S.l.] : S.n. - ISBN 9789085048725 - 142
    zeugen - oestrus - lactatie - follikels - groei - hormonen - zwangerschap - zogen - embryonale ontwikkeling - voortplanting - sows - oestrus - lactation - follicles - growth - hormones - pregnancy - suckling - embryonic development - reproduction
    Keywords: sow; Intermittent Suckling; oestrus; lactation; oestradiol; LH; progesterone, embryo
    survival, embryo development, cystic ovaries.

    Weaning of piglets at a relatively young age (3 to 4 weeks) can compromise health and welfare. A
    possible way to increase piglet welfare is to extend lactation length, but this is economically
    undesirable due to lactational anoestrus of the sow. Thus, an extension of lactation would reduce the
    number of litters per sow per year. Intermittent Suckling (IS), a management system in which the
    lactating sow is separated from her litter for a fixed period of the day, is proposed as method to extend
    lactation length without compromising sow reproductive performance. The aims of this thesis were to
    study if by application of IS, lactational oestrus and ovulation could be induced in a large proportion
    of the sows and to examine the quality of such a lactational oestrus by studying hormone levels and
    pregnancy parameters. Within a first study, sows were separated from their piglets for either 12h
    continuously or at 6h intervals from d14 of lactation onwards. In a control group, weaning occurred at
    d21 of lactation. Lactational oestrus was induced in more than 80% of the sows. The pre-ovulatory LH
    surge, progesterone (P4) levels and the number of ovulating sows were negatively affected by IS and
    embryo development was negatively affected by the regimen of IS (6h). Low P4 levels have been
    related to a low embryo survival and one factor known to affect P4 levels was feeding level. Therefore,
    the aim of a second study was to examine the effect of the high lactational feeding level of IS sows on
    P4 levels. Multiparous sows, subjected to IS daily for 12h continuously, were fed at a high
    (±6.5kg/day) or low (±4kg/day) feeding level from ovulation to 6 days after ovulation. Results of this
    study indicated that P4 levels were not affected by high lactational feeding levels and that P4 levels
    were comparable to levels found in the first study. In a third study two other factors, possibly involved
    in the low P4 levels, were studied: timing of start of IS and continuance of IS during early pregnancy.
    Multiparous sows were subjected to IS for 12h continuously per day from d14 or d21 of lactation
    onwards. Weaning occurred either at ovulation or day 20 after ovulation. An early start of IS (d14) did
    not significantly affect the pre-ovulatory LH surge, but resulted in lower P4 levels at d7 after ovulation.
    Continuance of IS after ovulation resulted in lower P4 levels after ovulation and also negatively
    affected embryo development. Thus, lactational factors such as suckling related hormones or the
    metabolic state of the sow may caused the low P4 levels in IS sows. In general, a high proportion of IS
    sows developed cystic ovaries. In a final study, reproductive parameters were examined in sows
    developing cysts. Sows developing cysts lacked an LH surge. A dysfunction in oestradiol feedback
    seems the underlying mechanism responsible for the lack of the LH surge and may be related with
    stress or the metabolic state of IS sows. In conclusion, it is possible by means of IS to induce
    lactational oestrus and ovulation. The rate of success, however, is dependent on several factors such as
    the breed of the sow and the timing of start of IS. The quality of lactational oestrus (hormone levels,
    embryo survival) seems comparable to weaned sows when start of IS is not too early after farrowing
    and IS is not continued during early pregnancy.
    The pregnancy: time for a new beginning! : exploring opportunities and challenges for healthy nutrition promotion
    Szwajcer, E.M. - \ 2007
    Wageningen University. Promotor(en): Gerrit Jan Hiddink; Cees van Woerkum, co-promotor(en): Maria Koelen. - [S.l.] : S.n. - ISBN 9789085046707 - 170
    zwangerschap - dieet - voedingseducatie - voedingsinformatie - gezondheidsbevordering - voedingsgedrag - vrouwen - pregnancy - diet - nutrition education - nutrition information - health promotion - feeding behaviour - women
    In literature it has been suggested that there are certain special and critical transitions in life that my have a long-term impact on health and health behaviours in later periods of the life course. This is also known as the Life Course Perspective (LCP). The purpose of this thesis was to contribute to the rationale of healthy nutrition promotion activities aimed at women and their health behaviour in and around pregnancy, as such a special and critical transition in life. This was done by means of cross-sectional studies on nutrition awareness (qualitative and quantitative), nutrition-related information-seeking behaviours (qualitative) and underlying motivations (qualitative) among women before, during and after their pregnancy. In order to do this, the concept of nutrition awareness was explored and redefined. Mostly, awareness is defined as a matter of knowing about something. The result of this conceptualisation is that the link with behaviour becomes a problematic one. Therefore, we have chosen for a more ‘active’. Nutrition awareness was defines as in saliency, preoccupation and supervision of nutrition. Furthermore, we looked at the autonomy of motivations of nutrition awareness. Autonomously motivated women in the period around the pregnancy are more likely to make longer lasting behavioural changes, which is favour of the LCP. Finally, special attention was paid to nutrition communication in the midwifery practice as a more specific setting for healthy nutrition promotion directed at all pregnant women. The results of these studies showed that the LCP is a new and hardly or insufficient explored domain in nutrition promotion and pregnancy. It can be concluded that the LCP-concept provides interesting opportunities for healthy nutrition promotion directed at women who are starting a family. In transition to pregnancy and motherhood, women are motivated to change health-related behaviours that are difficult to modify at other times. Moreover, it can be concluded that our conceptualisation of awareness is fruitful in obtaining a better understanding of possible behavioural changes in health in relation to the LCP. Also nutrition awareness, nutrition-related information-seeking behaviours and associated motivations are a good basis for distinguishing groups of women in the period around their pregnancy.
    Quantitative Aspects of Ruminant Digestion and Metabolism
    Dijkstra, J. ; Forbes, J.M. ; France, J. - \ 2005
    Wallingford, United Kingdom : CAB International - ISBN 9780851998145 - 734
    herkauwers - spijsvertering - metabolisme - voer - verteerbaarheid - pens - voederwaardering - zwangerschap - lactatie - wiskundige modellen - voedingsfysiologie - ruminants - digestion - metabolism - feeds - digestibility - rumen - feed evaluation - pregnancy - lactation - mathematical models - nutrition physiology
    The first edition of this book, published in 1993, provides a comprehensive review of the digestion and metabolism of ruminant animals. Since its publication, much new research has been conducted in the subject and knowledge has increased. This is incorporated in this second edition through the addition of five new chapters. These cover; the gas production technique in feed evaluation; calorimetry; the relationship between pasture characteristics and animal performance; feed processing; and the integration of data in feed evaluation systems. Other chapters have been expanded and updated as appropriate and Dr Dijkstra has also been enrolled as the lead editor. This book brings together quantitative approaches used in the study of mechanisms of ruminant digestion and metabolism and related areas from different contributing practitioners, experts and scientists
    Ruwvoer of stro voor drachtige zeugen = Silage or straw for pregnant sows
    Mheen, H. van der; Spoolder, H.A.M. ; Kiezebrink, M.C. - \ 2004
    Lelystad : Animal Sciences Group (PraktijkRapport / Animal Sciences Group, Praktijkonderzoek : Varkens ) - 17
    zeugen - kuilvoer - stro - ruwvoer (roughage) - agressief gedrag - diergedrag - dierenwelzijn - zwangerschap - groepshuisvesting - sows - silage - straw - roughage - aggressive behaviour - animal behaviour - animal welfare - pregnancy - group housing
    Varkenshouders dienen agressie tussen varkens te minimaliseren. In groepen zeugen treedt agressie echter regelmatig op, en in wisselgroepen vaker dan in stabiele groepen. Uit onderzoek blijkt dat het gebruik van ruwvoer of stro de agressie en stress kan verminderen. Er is echter ook onderzoek gedaan waaruit bleek dat door stro of ruwvoer zeugen actiever worden, met meer kans op confrontaties tussen de dieren. Het doel van dit onderzoek was de effecten te bepalen van ruwvoer of stro op het welzijn, gemeten aan huidbeschadigingen en eetgedrag, bij zeugen in wisselgroepen
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