Eric A.P. Steegers

Periconceptional Maternal Folic Acid Use of 400 µg per Day Is Related to Increased Methylation of the IGF2 Gene in the Very Young Child

Background Countries worldwide recommend women planning pregnancy to use daily 400 µg of synthetic folic acid in the periconceptional period to prevent birth defects in children. The underlying mechanisms of this preventive effect are not clear, however, epigenetic modulation of growth processes by folic acid is hypothesized. Here, we investigated whether periconceptional maternal folic acid use and markers of global DNA methylation potential (S-adenosylmethionine and S-adenosylhomocysteine blood levels) in mothers and children affect methylation of the insulin-like growth factor 2 gene differentially methylation region (IGF2 DMR) in the child. Moreover, we tested whether the methylation of the IGF2 DMR was independently associated with birth weight. Methodology/Principal Findings IGF2 DMR methylation in 120 children aged 17 months (SD 0.3) of whom 86 mothers had used and 34 had not used folic acid periconceptionally were studied. Methylation was measured of 5 CpG dinucleotides covering the DMR using a mass spectrometry-based method. Children of mother who used folic acid had a 4.5% higher methylation of the IGF2 DMR than children who were not exposed to folic acid (49.5% vs. 47.4%; p = 0.014). IGF2 DMR methylation of the children also was associated with the S-adenosylmethionine blood level of the mother but not of the child (+1.7% methylation per SD S-adenosylmethionine; p = 0.037). Finally, we observed an inverse independent association between IGF2 DMR methylation and birth weight (−1.7% methylation per SD birthweight; p = 0.034). Conclusions Periconceptional folic acid use is associated with epigenetic changes in IGF2 in the child that may affect intrauterine programming of growth and development with consequences for health and disease throughout life. These results indicate plasticity of IGF2 methylation by periconceptional folic acid use.

Maternal Thyroid Function during Early Pregnancy and Cognitive Functioning in Early Childhood: The Generation R Study

CONTEXT Thyroid hormones are essential for neurodevelopment from early pregnancy onward. Yet population-based data on the association between maternal thyroid function in early pregnancy and childrens cognitive development are sparse. OBJECTIVE Our objective was to study associations of maternal hypothyroxinemia and of early pregnancy maternal TSH and free T(4)(FT(4)) levels across the entire range with cognitive functioning in early childhood. DESIGN AND SETTING We conducted a population-based cohort in The Netherlands. PARTICIPANTS Participants included 3659 children and their mothers. MAIN MEASURES In pregnant women with normal TSH levels at 13 wk gestation (SD = 1.7), mild and severe maternal hypothyroxinemia were defined as FT(4) concentrations below the 10th and 5th percentile, respectively. Childrens expressive vocabulary at 18 months was reported by mothers using the MacArthur Communicative Development Inventory. At 30 months, mothers completed the Language Development Survey and the Parent Report of Childrens Abilities measuring verbal and nonverbal cognitive functioning. RESULTS Maternal TSH was not related to the cognitive outcomes. An increase in maternal FT(4) predicted a lower risk of expressive language delay at 30 months only. However, both mild and severe maternal hypothyroxinemia was associated with a higher risk of expressive language delay across all ages [odds ratio (OR) = 1.44; 95% confidence interval (CI) = 1.09-1.91; P = 0.010 and OR = 1.80; 95% CI = 1.24-2.61; P = 0.002, respectively]. Severe maternal hypothyroxinemia also predicted a higher risk of nonverbal cognitive delay (OR = 2.03; 95% CI = 1.22-3.39; P = 0.007). CONCLUSIONS Maternal hypothyroxinemia is a risk factor for cognitive delay in early childhood.

Congenital cytomegalovirus infection: review of the epidemiology and outcome.

Cytomegalovirus (CMV) is one of the most common viral causes of congenital infection. A future decision to lower its incidence by vaccination will depend on epidemiological conditions within a country and on the safety of the vaccine to be used, because a life vaccine may cause latency and subsequent reactivation that still may harm the fetus. The aim was to review the epidemiological studies published so far, with respect to factors that affect the incidence of congenital CMV infection, and factors that may influence its outcome, such as preexisting maternal immunity. The study included the data of 19 studies that were retrieved from a MEDLINE search during the period 1977 to 1997. The incidence of congenital CMV infection varied between 0.15% and 2.0% and seemed to correlate with the level of preexisting immunity in the population. Although preexisting maternal immunity was reported to strongly reduce transmission, the severity of congenital CMV infection (symptoms at birth and or sequelae later in life) was not significantly greater after virus transmission due to a primary infection of the mother as compared with recurrence or reinfection. The data indicate that preexisting immunity of the mother does not significantly mitigate the outcome of congenital infection. Moreover, life vaccines may bear a serious risk when transmittable to the fetus. Target Audience: Obstetricians and Gynecologists, Family Physicians Learning Objectives: After completion of this article, the reader will be able to describe the natural course of a CMV infection, to list the potential sequelae of a congenital CMV infection, to outline potential strategies to prevent transmission of CMV, and to summarize the diagnostic work up of a patient with a potential CMV infection.

The Generation R Study Biobank: a resource for epidemiological studies in children and their parents

The Generation R Study is a population-based prospective cohort study from fetal life until young adulthood. The study is designed to identify early environmental and genetic causes of normal and abnormal growth, development and health from fetal life until young adulthood. In total, 9,778 mothers were enrolled in the study. Prenatal and postnatal data collection is conducted by physical examinations, questionnaires, interviews, ultrasound examinations and biological samples. Major efforts have been conducted for collecting biological specimens including DNA, blood for phenotypes and urine samples. In this paper, the collection, processing and storage of these biological specimens are described. Together with detailed phenotype measurements, these biological specimens form a unique resource for epidemiological studies focused on environmental exposures, genetic determinants and their interactions in relation to growth, health and development from fetal life onwards.

Urinary metabolite concentrations of organophosphorous pesticides, bisphenol A, and phthalates among pregnant women in Rotterdam, the Netherlands : The Generation R study

Concern about potential health impacts of low-level exposures to organophosphorus (OP) pesticides, bisphenol A (BPA), and phthalates among the general population is increasing. We measured levels of six dialkyl phosphate (DAP) metabolites of OP pesticides, a chlorpyrifos-specific metabolite (3,5,6-trichloro-2-pyridinol, TCPy), BPA, and 14 phthalate metabolites in urine samples of 100 pregnant women from the Generation R study, the Netherlands. The unadjusted and creatinine-adjusted concentrations were reported, and compared to National Health and Nutrition Examination Survey and other studies. In general, these metabolites were detectable in the urine of the women from the Generation R study and compared with other groups, they had relatively high-level exposures to OP pesticides and several phthalates but similar exposure to BPA. The median concentrations of total dimethyl (DM) metabolites was 264.0 n mol/g creatinine (Cr) and of total DAP was 316.0 n mol/g Cr. The median concentration of mono-ethyl phthalate (MEP) was 222.0 microg/g Cr; the median concentrations of mono-isobutyl phthalate (MiBP) and mono-n-butyl phthalate (MnBP) were above 50 microg/g Cr. The median concentrations of the three secondary metabolites of di-2-ethylhexyl phthalate (DEHP) were greater than 20 microg/g Cr. The data indicate that the Generation R study population provides a wide distribution of selected environmental exposures. Reasons for the relatively high levels and possible health effects need investigation.

Active and passive maternal smoking during pregnancy and the risks of low birthweight and preterm birth: the Generation R Study

The objective of this study was to examine the associations between active and passive smoking in different periods of pregnancy and changing smoking habits during pregnancy, with low birthweight and preterm birth. The study was embedded in the Generation R Study, a population-based prospective cohort study from early fetal life onwards in Rotterdam, The Netherlands. Active and passive smoking were assessed by questionnaires in early, mid- and late pregnancy. Analyses were based on 7098 pregnant women and their children. Active smoking until pregnancy was ascertained and was not associated with low birthweight and preterm birth. Continued active smoking after pregnancy was also recorded and was associated with low birthweight (adjusted odds ratio 1.75 [95% CI 1.20, 2.56]) and preterm birth (adjusted odds ratio 1.36 [95% CI 1.04, 1.78]). The strongest associations were found for active maternal smoking in late pregnancy. Passive maternal smoking in late pregnancy was associated with continuously measured birthweight (P for trend <0.001). For all active smoking categories in early pregnancy, quitting smoking was associated with a higher birthweight than continuing to smoke. Tendencies towards smaller non-significant beneficial effects on mean birthweight were found for reducing the number of cigarettes without quitting completely. This study shows that active and passive smoking in late pregnancy are associated with adverse effects on weight and gestational age at birth. Smoking in early pregnancy only, seems not to affect fetal growth adversely. Health care strategies for pregnant women should be aimed at quitting smoking completely rather than reducing the number of cigarettes.

Homocysteine and folate levels as risk factors for recurrent early pregnancy loss

Objective To estimate the relative risk of recurrent early pregnancy loss for different total plasma homocysteine and serum folate concentrations. Methods In a case-control study, we measured homocysteine (fasting and afterload), folate (serum and red cells), pyridoxal 5′-phosphate, and cobalamin concentrations in 123 women who had at least two consecutive spontaneous early pregnancy losses each and compared concentrations with those of 104 healthy controls. Results Women with recurrent early pregnancy losses had significantly lower serum folate concentrations than controls, whereas the other measurements were similar to those of controls. Elevated homocysteine, fasting greater than 18.3 μmol/L and afterload greater than 61.5 μmol/L, was a risk factor for recurrent early pregnancy loss, with odds ratios (ORs) and 95% confidence intervals (95% CIs) of 3.6 (1.2, 12.7) and 2.7 (0.9, 8.8) in the group with recurrent miscarriages: 6.4 (1.9, 24.3) and 4.3 (1.2, 17.3) in primary aborters, and 4.2 (1.3, 15.4) and 3.4 (1.0, 12.8) in those with three or more miscarriages. The ORs (95% CIs) in the same study populations for serum folate concentrations less than 8.4 nmol/L were 2.1 (0.9, 4.8), 2.7 (1.0, 7.8), and 3.2 (1.3, 8.1), respectively. A significant dose-response relationship between serum folate concentrations and risk of recurrent early pregnancy loss suggested a protective effect by high serum folate concentrations. Conclusion Elevated homocysteine and reduced serum folate concentrations were risk factors for recurrent spontaneous early pregnancy losses. Folic acid supplementation might be beneficial in women with histories of early pregnancy loss.

Risk Factors and Outcomes Associated With First-Trimester Fetal Growth Restriction

CONTEXT Adverse environmental exposures lead to developmental adaptations in fetal life. The influences of maternal physical characteristics and lifestyle habits on first-trimester fetal adaptations and the postnatal consequences are not known. OBJECTIVE To determine the risk factors and outcomes associated with first-trimester growth restriction. DESIGN, SETTING, AND PARTICIPANTS Prospective evaluation of the associations of maternal physical characteristics and lifestyle habits with first-trimester fetal crown to rump length in 1631 mothers with a known and reliable first day of their last menstrual period and a regular menstrual cycle. Subsequently, we assessed the associations of first-trimester fetal growth restriction with the risks of adverse birth outcomes and postnatal growth acceleration until the age of 2 years. The study was based in Rotterdam, The Netherlands. Mothers were enrolled between 2001 and 2005. MAIN OUTCOME MEASURES First-trimester fetal growth was measured as fetal crown to rump length by ultrasound between the gestational age of 10 weeks 0 days and 13 weeks 6 days. Main birth outcomes were preterm birth (gestational age <37 weeks), low birth weight (<2500 g), and small size for gestational age (lowest fifth birth centile). Postnatal growth was measured until the age of 2 years. RESULTS In the multivariate analysis, maternal age was positively associated with first-trimester fetal crown to rump length (difference per maternal year of age, 0.79 mm; 95% confidence interval [CI], 0.41 to 1.18 per standard deviation score increase). Higher diastolic blood pressure and higher hematocrit levels were associated with a shorter crown to rump length (differences, -0.40 mm; 95% CI, -0.74 to -0.06 and -0.52 mm; 95% CI, -0.90 to -0.14 per standard deviation increase, respectively). Compared with mothers who were nonsmokers and optimal users of folic acid supplements, those who both smoked and did not use folic acid supplements had shorter fetal crown to rump lengths (difference, -3.84 mm; 95% CI, -5.71 to -1.98). Compared with normal first-trimester fetal growth, first-trimester growth restriction was associated with increased risks of preterm birth (4.0% vs 7.2%; adjusted odds ratio [OR], 2.12; 95% CI, 1.24 to 3.61), low birth weight (3.5% vs 7.5%; adjusted OR, 2.42; 95% CI, 1.41 to 4.16), and small size for gestational age at birth (4.0% vs 10.6%; adjusted OR, 2.64; 95% CI, 1.64 to 4.25). Each standard deviation decrease in first-trimester fetal crown to rump length was associated with a postnatal growth acceleration until the age of 2 years (standard deviation score increase, 0.139 per 2 years; 95% CI, 0.097 to 0.181). CONCLUSIONS Maternal physical characteristics and lifestyle habits were independently associated with early fetal growth. First-trimester fetal growth restriction was associated with an increased risk of adverse birth outcomes and growth acceleration in early childhood.

Genetic risk factor for unexplained recurrent early pregnancy loss.

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Association of Higher Rheumatoid Arthritis Disease Activity During Pregnancy With Lower Birth Weight Results of a National Prospective Study

OBJECTIVE To determine the outcome of pregnancy in women with rheumatoid arthritis (RA) in relation to disease activity and medication use during the pregnancy. METHODS In a prospective study, pregnant women with RA were evaluated before conception (when possible), during each trimester of the pregnancy, and postpartum. Clinical characteristics, disease activity, medication use, and pregnancy outcome were analyzed. To examine the independent influence of prednisone use and disease activity on birth weight, regression analyses were performed, with adjustments for gestational age of the child at delivery, the sex of the newborn, and the mothers smoking status, education level, parity, and use of an assisted reproduction technique. Kaplan-Meier curve analyses were performed to examine the association between medication use and gestational age at delivery. RESULTS Data from 152 Caucasian RA patients with singleton pregnancies were available. Both the mean +/- SD birth weight (3,379 +/- 564 gm) and the mean +/- SD birth weight standard deviation score (SDS; +0.1 +/- 1.1), which is the birth weight adjusted for the gestational age and sex of the newborn, were comparable with those in the general population. On multiple linear regression analyses of birth weight and birth weight SDS, both of which were adjusted for covariates, only disease activity was associated with lower birth weight (P = 0.025). The gestational age at delivery was significantly lower in women who were taking prednisone (38.8 versus 39.9 weeks; P = 0.001), and their delivery was more often premature (<37 weeks; P = 0.004). CONCLUSION Pregnancy outcome in women with well-controlled RA is comparable with that in the general population. The effect of prednisone on birth weight is mediated by a lower gestational age at delivery, whereas a higher level of disease activity independently influences birth weight negatively, suggesting an immune-mediated mechanism.