Skin aging associated with chromium among rural housewives in northern China.

Previous studies have found associations between chromium exposure and skin damage. However, few studies have focused on both chromium and skin aging. This study aimed to assess the degree of skin aging symptoms and estimate the relationship between hair chromium and skin aging among rural housewives. We recruited 405 subjects in Shanxi Province of northern China and analyzed 397 eligible hair samples with inductively coupled plasma-mass spectrometry (ICP-MS). The subjects' skin aging symptoms were assessed with SCINEXA™ (SCore of INtrinsic and EXtrinsic skin Aging). After adjusting for age and other important covariates, the regression results showed more severe skin aging symptoms in women with a higher level of hair chromium and presented an increasing linear trend. Vegetables, fruits, and beans might be a source of chromium exposure. We concluded that skin aging might be positively associated with hair chromium. It is necessary to take measures to reduce chromium exposure to prevent skin aging.

Folic acid supplementation and risk for fetal abdominal wall defects in China: results from a large population-based intervention cohort study.

Folic acid (FA) can reduce the risk for selected birth defects other than neural tube defects. We examined whether FA has preventive effects against fetal abdominal wall defects (AWD) in a unique intervention cohort in China. Birth outcomes of 247 831 singleton births from a population-based cohort study with detailed pre-conceptional FA intake information were collected in China in 1993-1996. Information on births at 20 complete gestational weeks, including live births, stillbirths and pregnancy terminations, and all structural birth defects regardless of gestational week were recorded. The birth prevalence of omphalocele, gastroschisis and total fetal AWD was classified by maternal FA supplementation. The prevalence of total AWD was 4·30 per 10 000 births among women who took FA compared with 13·46 per 10 000 births among those who did not take FA in northern China and 6·28 and 5·18 per 10 000 births, respectively, in southern China. The prevalence of omphalocele was 0·54 per 10 000 births among women who took FA compared with 3·74 per 10 000 births among those who did not take FA in northern China and 1·79 and 1·44 per 10 000 births, respectively, in southern China. FA supplementation significantly prevented total AWD in multivariate analysis (relative risk 0·26, 95 % CI 0·11, 0·61) in northern China, although no preventive effect of FA on AWD was observed in southern China. FA supplementation successfully reduced the prevalence of AWD in northern China.

Folic acid supplementation and risk for congenital hydrocephalus in China.

OBJECTIVE: We examined whether folic acid (FA) supplementation prevented congenital hydrocephalus (CH) in more than 200 000 births in China. DESIGN: A large population-based cohort study. SETTING: All births at 20 complete gestational weeks, including live births, stillbirths and pregnancy terminations, and all structural birth defects regardless of gestational week were recorded. The prevalence of births with CH was classified by maternal characteristics and FA supplementation. CH was diagnosed in accordance with code 742.3 of the International Classification of Diseases, Ninth Revision, Clinical Modification, while non-neural tube defect (NTD) CH refers to CH without anencephaly (740), spina bifida (741) or encephalocele (742·0). PARTICIPANTS: A total of 247 831 pregnant women who delivered with known outcomes were included. RESULTS: A total of 206 cases of CH (0·83 per 1000 births) and 170 cases of non-NTD CH (0·69 per 1000 births) were recorded in the study. The prevalence of CH and non-NTD CH was higher in women in the no supplementation group than those in the FA supplementation group (0·92 and 0·72 v. 0·75 and 0·65 per 1000 births, respectively). FA supplementation during the periconceptional period significantly prevented CH (OR = 0·29, 95 % CI 0·12, 0·69) and non-NTD CH (OR = 0·34, 95 % CI 0·12, 0·97) in northern China, especially in a high-compliance group (≥ 80 %). CONCLUSIONS: Periconceptional FA supplementation did not significantly prevent CH overall in the current study. However, in the north of China with common maternal folate insufficiency, there was some evidence.

Association between tea drinking and plasma folate concentration among women aged 18-30 years in China.

OBJECTIVE: Association was found between tea and neural tube defects. However, few studies investigated the relationship between tea consumption and blood folate levels. We aimed to investigate the association between tea consumption and plasma folate concentrations among women aged 18-30 years in different ethnicities of China. DESIGN: Data were obtained from a national cross-sectional study conducted from 2005 to 2006 of women aged 18-30 years in China. Socio-demographic characteristics and lifestyle were obtained from a questionnaire. Dietary folate intake was determined by 24-h dietary recall. Plasma folate concentrations were measured by a microbiological assay. Multiple linear regression model was used to calculate partial regression coefficients after adjusting for confounding factors. SETTING: Nine provinces or autonomous regions in China. PARTICIPANTS: A total of 2932 women aged 18-30 years in China. RESULTS: After stratifying by ethnicity and tea type, tea consumption was significantly positively associated with plasma folate levels in Han women who drank unfermented tea weekly (ß = 0·067, and P = 0·037) or daily (ß = 0·119, and P = 0·031) and in Uighur women who drank fermented tea weekly (ß = 0·325, and P = 0·028). For women who drank unfermented tea in Han ethnicity, weekly and daily tea drinkers had 6·77 % (95 % CI: 6·36 %, 7·21 %) and 7·13 % (95 % CI: 6·40 %, 7·96 %) increase in plasma folate concentration compared with no tea drinkers. CONCLUSIONS: There is a suggestion of possible positive association between unfermented tea drinking in Han ethnicity and plasma folate concentrations, for Chinese women aged 18-30 years. The relationship between tea drinking in other ethnic groups and plasma folate still needs to be further explored.

Environmental titanium exposure and reproductive health: Risk of low birth weight associated with maternal titanium exposure from a nested case-control study in northern China.

Titanium (Ti) is commonly used in additives in the form of titanium dioxide (TiO2). However, our understanding of the effect of Ti on reproductive health remains limited. This nested case-control study, performed in a Ti mining exposure field, investigated the association between maternal blood Ti concentration and the risk of low birth weight (LBW), as well as the potential biological mechanism. A total of 45 women who delivered LBW infants (cases) and 352 women with normal birth weight infants (controls) were included. We collected maternal peripheral blood samples in the first or early second trimester to measure Ti concentration in serum (Tisr) and blood cells (Tibc), as well as inflammatory, lipid, and oxidative stress biomarkers thereof. The demographic characteristics of the women included in the study were also obtained. The results showed that the median total blood Ti concentration (Titb) in the case group was significantly higher than that in the control group (134 vs. 129 ng/mL, P = 0.039). A higher Titb level was associated with a greater risk of LBW [odds ratio = 2.62; 95% confidence interval (CI): 1.16-5.90], but no such association was observed for Tisr or Tibc after adjusting for potential confounders. The serum lipid biomarkers TC, TG, and total lipids (TL) were all negatively associated with Tisr and Titb. Serum 8-OHdG was positively associated with Tibc. We concluded that a high Titb during early pregnancy may increase the risk of LBW. Lipid metabolism and oxidative stress may play an important role in the adverse health effects associated with Ti exposure. Thus, our results merit more attention to the probable adverse effects of titanium exposure during pregnancy.

Distribution of mercury in serum and blood cells and risk of spontaneous preterm birth: A nested case-control study in China.

The relationship between maternal mercury (Hg) intake and the risk of spontaneous preterm birth (SPB) remains unclear. We conducted a nested case-control study from a prospective cohort in Shanxi Province, China, to explore their associations. In total, 126 pregnant women with SPB (cases) and 348 controls with term delivery were included. We measured the Hg concentrations in their serum (Hgs) and blood cell (Hgc) fractions and calculated the concentration ratio of Hg in serum to Hg in blood cells (Hgs/c). We found that only the Hgs/c in the case group was slightly higher than that in control group. The OR of Hgs/c associated with SPB risk was 1.57 [95%CI: 0.99-2.46] with adjusting confounders. After stratification by sampling time, the association above was only statistically significant in the first trimester. High Hgs/c may increase the risk of SPB in the first trimester among women with relatively low Hg exposure.

Effects of prenatal micronutrients supplementation timing on pregnancy-induced hypertension: Secondary analysis of a double-blind randomized controlled trial.

In this secondary analysis of data from a double-blind randomized controlled trial (clinicaltrials.gov identifier: NCT00133744) of micronutrient supplementation (multiple micronutrients [MMN], iron-folic acid [IFA] and folic acid [FA] alone), we examined the potential modifying effect of gestational age at enrolment on the association of antenatal supplementation and pregnancy-induced hypertension (PIH). We included 18,775 nulliparous pregnant women with mild or no anaemia who were enrolled at 20 weeks of gestation or earlier from five counties of northern China. Women were randomly assigned to receive daily FA, IFA or MMN from enrolment until delivery. We used logistic regression to evaluate the association between PIH and timing of micronutrient supplementation. The incidence of PIH was statistically significantly lower among women who began MMN supplementation before 12 gestational weeks compared with women who began MMN supplementation at 12 weeks or later (RR = 0.74, 95% CI: 0.60-0.91). A similar protective effect was observed for both early-onset (<28 weeks, RR 0.45, 0.21-0.96) and late-onset of PIH (≥28 weeks, RR 0.77, 0.63-0.96). No statistically significant association was observed between PIH occurrence and timing of supplementation for FA or IFA. Maternal MMN supplementation and antenatal enrolment during the first trimester of pregnancy appeared to be of importance in preventing both early- and late-onset of PIH.

Association between gestational weight gain and exclusive breast-feeding for the first 6 months postpartum in Chinese women.

OBJECTIVE: The association between gestational weight gain (GWG) and exclusive breast-feeding (EBF) practices remains unclear. The present study evaluated the association between GWG and EBF in the first 6 months postpartum among primiparas in rural China. DESIGN: The study population was drawn from a previous randomized controlled trial, and the relevant data were obtained from an electronic, population-based perinatal system and a monitoring system for child health care. GWG was categorized according to the guidelines of the Institute of Medicine. SETTING: Five rural counties in Hebei Province, China.ParticipantsA total of 8449 primiparas. RESULTS: Of the women, 58·7 % breast-fed exclusively for the first 6 months postpartum. Overweight women who gained either more or less weight than the recommended GWG tended to experience failure of EBF (OR=0·49; 95 % CI 0·34, 0·70; P<0·001 and OR=0·79; 95 % CI 0·63, 0·99; P=0·048, respectively). The same results were also observed among obese women; the OR for lower and greater weight gain were 0·28 (95 % CI 0·08, 0·94; P=0·04) and 0·55 (95 % CI 0·32, 0·95; P=0·03), respectively. CONCLUSIONS: GWG that is below or above the Institute of Medicine recommendations is associated with EBF behaviour for the first 6 months postpartum in overweight and obese primiparas in rural China.

Periconceptional folic acid supplementation and sex difference in prevention of neural tube defects and their subtypes in China: results from a large prospective cohort study.

BACKGROUND: Folic acid (FA) supplementation is known to prevent neural tube defects (NTDs). We examined whether this preventive effect differs by the sex of the infant. METHODS: Data were gathered from a large population-based cohort study in China that evaluated the effects of FA supplementation on NTDs. All births at 20 complete gestational weeks, including live births, stillbirths, and pregnancy terminations, and all NTDs, regardless of gestational age, were recorded. In a northern China province, a total of 30,801 singleton live births to women whose use of FA supplements during the first trimester was known at the time were included in the study. The birth prevalence of NTDs was classified by sex, subtype, and maternal FA supplementation. Male to female rate ratios [RR] and their 95% confidence intervals [CI] were calculated. RESULTS: A total of 106 NTDs cases were recorded. The overall prevalence of NTDs was 2.5‰ among males and 4.4‰ among females; NTDs were less prevalent among males than among females (RR, 0.58; 95% CI, 0.54-0.63). There was a higher prevalence of anencephaly (RR, 0.34; 95% CI, 0.27-0.43) and spina bifida (RR, 0.73; 95% CI, 0.63-0.84) among females. However, FA supplementation led to significantly greater decreases in the rates of anencephaly (4.8‰) and total NTDs (7.6‰) in females than in males (1.6‰ and 2.8‰, respectively). CONCLUSIONS: FA supplementation successfully reduces the prevalence of NTDs in both male and female infants, although we found a significantly greater decrease in anencephaly and total NTDs in females than in males. How the protective effects of FA supplementation affect the sexes differently needs to be studied further.

Maternal haemoglobin concentration and risk of preterm birth in a Chinese population.

The aim was to examine the relationship between maternal haemoglobin (Hb) concentrations and risk of preterm birth by secondary analysis of data from a randomised controlled trial. This analysis included 10,430 women who were at least 20 years old and no more than 20 weeks of gestation. Results revealed neither first- nor second-trimester Hb concentrations were associated with the risk of preterm births. However, the risk of preterm birth increased when the Hb level was low (<130 g/L) in the first but high (≥130 g/L) in the second trimester, regardless of supplement type (iron-containing: AOR: 2.26, 95% CI: 1.37-3.73; non-iron-containing: AOR: 2.16, 95% CI: 1.11-4.21). In conclusion, maternal Hb concentrations were not associated with the risk of preterm birth. A low-Hb level in the first trimester but coupled with a high Hb level in the second was associated with an elevated risk of preterm birth. Impact statement What is already known on this subject: The relationship between maternal Hb concentration and preterm birth remains inconclusive. Some studies have shown an association between a low- or a high-Hb level and an increased risk of preterm birth. Others have not found such an association. Yet others have shown a U-shaped relationship. What do the results of this study add: Overall, maternal Hb concentrations in first or second trimester were not statistically associated with the risk of preterm birth. However, women with a low Hb concentration in the first trimester together with a high Hb concentration in the second trimester had an increased risk of preterm birth, compared to women who had a higher Hb concentration in the first trimester that remained similar during the second trimester. What are the implications are of these findings for clinical practice and/or further research: Our finding helps identify mothers who are at risk of having a preterm delivery. Investigating the underlying clinical causes of the unfavourable change in Hb levels and close follow-up to these women may help improve birth outcomes.

Effects of Prenatal Micronutrient Supplementation on Spontaneous Preterm Birth: A Double-Blind Randomized Controlled Trial in China.

In this secondary analysis of data from a double-blind randomized controlled trial carried out in northern China, we aimed to assess the effect of prenatal supplementation with multiple micronutrients (MMN) or iron + folic acid (IFA), versus folic acid (FA) alone, on risk of spontaneous preterm birth (SPB) and the impact of supplementation timing on SPB. A total of 18,775 nulliparous pregnant women enrolled between 2006 and 2009 were randomly assigned to receive daily FA, IFA, or MMN from the period before 20 weeks' gestation to delivery. The incidences of SPB for women consuming FA, IFA, and MMN were 5.7%, 5.6% and 5.1%, respectively. Compared with women given FA, the relative risks of SPB for those using MMN and IFA were 0.99 (95% confidence interval: 0.85, 1.16) and 0.89 (95% confidence interval: 0.79, 1.05), respectively. SPB incidence in women who started consuming FA, IFA, and MMN before the 12th week of gestation (4.6%, 4.2%, and 3.9%, respectively) was significantly reduced compared with starting supplement use on or after the 12th gestational week (6.9%, 7.2%, and 6.4%, respectively). Starting use of FA, IFA, or MMN supplements before the 12th week of gestation produced a 41%-45% reduction in risk of SPB. Early prenatal enrollment and micronutrient use during the first trimester of pregnancy appeared to be of particular importance for prevention of SPB, regardless of supplement group.

Impact of Periconceptional Folic Acid Supplementation on Low Birth Weight and Small-for-Gestational-Age Infants in China: A Large Prospective Cohort Study.

OBJECTIVES: To explore the effects of maternal folic acid supplementation alone during pregnancy on the incidence of low birth weight (LBW) and small-for-gestational-age (SGA) infant status. STUDY DESIGN: Data were derived from a large population-based cohort study performed in China to evaluate the prevention of neural tube defects with folic acid supplementation. The sample comprised 200 589 singleton live births registered in 2 southern Chinese provinces by mothers for whom detailed information on folic acid use was available. Gestational age was calculated from the first day of the last menstrual period. LBW was defined as a birth weight <2500 g. Infants were considered SGA when the age-adjusted birth weight was below the 10th percentile as defined by a national survey performed in 1998. Logistic regression was used to estimate the effects of folic acid after adjusting for the principal potential confounders. RESULTS: The overall incidence of LBW and SGA status was 2.18% and 5.82%, respectively. The incidence of LBW and SGA status was 2.09% and 5.73% in women who took folic acid, and 2.27% and 5.90% in those who did not. The adjusted risk ratios associated with folic acid use were 0.85 (95% CI: 0.80-0.90) for LBW and 0.93 (95% CI: 0.89-0.96) for SGA status. Folic acid use during pregnancy appeared to be particularly important to prevent LBW and SGA status. CONCLUSIONS: A maternal daily intake of 400 µg folic acid alone significantly reduced the risks of infant LBW and SGA status.

Maternal Hemoglobin Concentration during Gestation and Risk of Anemia in Infancy: Secondary Analysis of a Randomized Controlled Trial.

OBJECTIVE: This study examined the relationship between maternal hemoglobin (Hb) concentration and the risk of anemia in infancy. STUDY DESIGN: This analysis included 17 193 women who entered the trial when they were ≥20 years of age, no more than 20 weeks of gestation, had mild or no anemia, and delivered singleton live births. Maternal Hb concentrations were measured in the first trimester and during 24-28 weeks of gestation; infant Hb concentrations were measured at 5-7 months and 11-13 months of life. The associations between maternal Hb concentrations and infant Hb concentrations were examined. RESULTS: Maternal Hb concentrations measured during 24-28 weeks of gestation, but not in the first trimester, were correlated with infant Hb concentrations measured at either of the 2 post-partum periods. The risk of infant anemia at 5-7 months of age increased when maternal Hb concentration was ≤109 g/L during 24-28 weeks of gestation (aOR, 1.95; 95% CI, 1.59-2.40) and 11-13 months of age (aOR, 1.72; 95% CI, 1.36-2.18), whereas the risk of anemia during 5-7 months of age as well as 11-13 months in infancy decreased when maternal Hb level at 24-28 weeks of gestation was 120-129 g/L (aOR for 5-7 months, 0.74 [95% CI, 0.64-0.85]; aOR for 11-13 months, 0.72 [95% CI, 0.61-0.85]), or ≥130 g/L (aOR for 5-7 months, 0.75 [95% CI, 0.63-0.90]; aOR for 11-13 months, 0.89 [95% CI, 0.73-1.08]). CONCLUSIONS: Low maternal Hb concentration during 24-28 weeks of gestation was associated with an increased risk of anemia in infancy, whereas high maternal Hb concentration was associated with a reduced risk of anemia. TRIAL REGISTRATION: Clinicaltrials.gov: NCT00133744.

Prevalence and trend of neural tube defects in five counties in Shanxi province of Northern China, 2000 to 2014.

BACKGROUND: The prevalence of neural tube defects (NTDs) in northern China is among the highest in the world. A massive folic acid supplementation program as a specific countermeasure was introduced in 2009. Examining trends in NTD prevalence may provide evidence for future intervention. METHODS: Data for 2000 to 2014 in five counties in northern China were obtained through a population-based birth defects surveillance system. All live births, stillbirths of over 20 gestational weeks, and pregnancy terminations because of NTDs at any gestational age were recorded. The prevalence of NTDs by gestational weeks (< 28 vs. ≥ 28), by calendar year, and by subtype was presented. RESULTS: From 2000 to 2014, a total of 234,225 births and 2027 cases of NTDs were recorded. The prevalence of total NTDs was extremely high during 2000 to 2004, but it began to decrease continuously thereafter, from a peak of 120.0/10,000 in 2004 to a low of 31.5/10,000 in 2014. A significant decrease (60%) was observed from 78.8/10,000 in 2009 to 31.5/10,000 in 2014, 5 years after the folic acid supplementation program was introduced. All three major subtypes, namely anencephaly, spina bifida, and encephalocele, showed a decline over this period. Although the perinatal (≥ 28 gestational weeks) prevalence of NTDs decreased progressively, the pre-perinatal (< 28 gestational weeks) prevalence of NTDs remained high until 2011 and then decreased. CONCLUSION: The prevalence of NTDs remains high despite a substantial and continuous decrease over the past 15 years. To further reduce NTD risk in the population, fortification staples with folic acid should be considered.

Levels of folate receptor autoantibodies in maternal and cord blood and risk of neural tube defects in a Chinese population.

BACKGROUND: After years of periconceptional folic acid supplementation, the prevalence of neural tube defects (NTDs) remains stable following the remarkable reduction observed immediately after the fortification practice. There is accumulating evidence that folate receptor (FR) autoimmunity may play a role in the etiology of folate-sensitive NTDs. METHODS: From 2011 to 2013, 118 NTD cases and 242 healthy controls were recruited from a population-based birth defects surveillance system in Northern China. Enzyme-linked immunosorbent assay was used to measure FR autoantibodies in maternal and cord blood. Logistic regression models were used to estimate the odds ratios (OR) and 95% confidence intervals (95% CI). RESULTS: Plasma FR autoantibodies levels were significantly elevated in mothers of infants with NTDs compared with mothers of healthy controls. Using the lowest tertile as the referent group, 2.20-fold (95% CI, 0.71-6.80) and 5.53-fold increased odds (95% CI, 1.90-16.08) of NTDs were observed for the second and third tertile of immunoglobulin G (IgG), respectively, and the odds of NTDs for each successive tertile of IgM was 0.98 (95% CI, 0.35-2.75) and 3.49 (95% CI, 1.45-8.39), respectively. A dose-response relationship was found between FR autoantibodies levels and risk of NTDs (P < 0.001 for IgG, P = 0.002 for IgM). The same pattern was observed in both subtypes of spina bifida and anencephaly. No significant difference in levels of cord blood FR autoantibodies was observed. CONCLUSION: Higher levels of FR autoimmunity in maternal plasma are associated with elevated risk of NTDs in a dose-response manner. Birth Defects Research (Part A) 106:685-695, 2016. © 2016 Wiley Periodicals, Inc.

Poor sleep during the periconceptional period increases risk for neural tube defects in offspring.

BACKGROUND: Poor sleep has been studied in relation to various diseases. Few studies have investigated the effect of poor sleep on birth defects. METHODS: We examined the association of maternal poor sleep during periconceptional period and the risk of neural tube defects (NTDs) in offspring based on a large case-control study in northern China. The subjects included 629 NTD cases and 858 normal controls investigated between 2002 and 2007. Maternal sleep status was collected by health workers within first week after delivery. Logistic regression was used to estimate the odds ratio (OR) and 95% confidence interval (CI) of NTDs in association with poor sleep. RESULTS: The proportion of mothers with frequent poor sleep (≥4 days/week on average) was markedly higher in NTDs group (5.9%) than in control group (1.2%). In the multivariate analysis, frequent poor sleep was significantly associated with an increased risk of total NTDs (adjusted OR, 4.1; 95% CI, 1.9-8.8) and spina bifida subtype (adjusted OR, 6.4; 95% CI, 2.8-14.5). Frequent poor sleep showed a significant interaction with body mass index (BMI). Relative to women who reported poor sleep <4 days/week and with BMI < 24, frequent poor sleep showed a markedly higher increased risk of NTDs among overweight or obese women (adjusted OR, 11.8; 95% CI, 1.4-97.6) than women with BMI < 24 (adjusted OR, 2.5; 95% CI,1.1-5.9). CONCLUSION: Maternal frequent poor sleep during the periconceptional period may increase the risk for all NTDs and spina bifida. The association appears to be independent of some lifestyle factors that are closely associated with sleep quality.

Tea consumption is not associated with reduced plasma folate concentration among Chinese pregnant women.

BACKGROUND: The aim of this study was to evaluate the relationship between tea consumption and plasma folate concentration in populations with high and low prevalence of neural tube defects (NTDs) in China. METHODS: Cross-sectional survey was conducted in three cities/counties in China, in which 1724 pregnant women during early second trimester were recruited and interviewed about tea consumption and folic acid use in 2011 to 2012. A total of 5-ml nonfasting blood sample was collected and plasma folate concentration was determined by microbiological assay. RESULTS: Approximately 16.2% of the women reported that they had ever drank tea during and before the current pregnancy, women with higher educational level, and those who resided in urban were more likely to drink tea. Most of them prefer green tea (55.2%); 13.6% of women drank tea ">6 times/week," and 29.0% of them drank "less than once a week." The median of plasma folate concentration was 48.7 nmol/L in women who drank tea while it is 45.2 nmol/L in women who did not drink tea, with no statistical difference. The results showed there was no association between tea drinking and plasma folate concentration in Chinese pregnant women stratified by folic acid supplementation and other selected characteristics. CONCLUSION: Low level of tea drinking is not associated with decreased plasma folate concentration in the Chinese populations with high and low prevalence of NTDs.

Interaction between the SLC19A1 gene and maternal first trimester fever on offspring neural tube defects.

BACKGROUND: Many studies have indicated that the reduced folate carrier gene (SLC19A1) is associated with an increased risk of neural tube defects (NTDs). However, the interaction between the SLC19A1 gene variant and maternal fever exposure and NTD risk remains unknown. The aim of this study was to investigate whether the risk for NTDs was influenced by the interactions between the SLC19A1 (rs1051266) variant and maternal first trimester fever. METHODS: We investigated the potential interaction between maternal first trimester fever and maternal or offspring SLC19A1 polymorphism through a population-based case-control study. One hundred and four nuclear families with NTDs and 100 control families with nonmal newborns were included in the study. SLC19A1 polymorphism was determined using polymerase chain reaction-restricted fragment length polymorphism. RESULTS: Mothers who had the GG/GA genotype and first trimester fever had an elevated risk of NTDs (adjusted odds ratio, 11.73; 95% confidence interval, 3.02-45.58) as compared to absence of maternal first trimester fever and AA genotype after adjusting for maternal education, paternal education, and age, and had a significant interactive coefficient (γ = 3.17) between maternal GG/GA genotype and first trimester fever. However, there was no interaction between offspring's GG/GA genotype and maternal first trimester fever (the interactive coefficient γ = 0.97) after adjusting for confounding factors. CONCLUSION: Our findings suggested that the risk of NTDs was potentially influenced by a gene-environment interaction between maternal SLC19A1 rs1051266 GG/GA genotype and first trimester fever. Maternal GG/GA genotype may strengthen the effect of maternal fever exposure on NTD risk in this Chinese population.

Plasma folate levels in early to mid pregnancy after a nation-wide folic acid supplementation program in areas with high and low prevalence of neural tube defects in China.

BACKGROUND: Folic acid supplementation is recommended for all women of child-bearing age to prevent neural tube defects (NTDs). A nation-wide folic acid supplementation program was implemented in rural areas of China since 2009; however, changes in plasma folate levels in pregnant women were unknown. METHODS: A cross-sectional survey was conducted in 2011 to 2012, with 1736 pregnant women enrolled, and results were compared with a previous survey in 2002 to 2004. A microbiological method was used to determine plasma folate levels. Preprogram and postprogram median plasma folate concentrations were compared while stratified by prevalence of NTDs and residence. RESULTS: In the high NTD prevalence population, plasma folate concentration increased to 33.4 (18.7, 58.4) nmol/L in the postprogram sample, which is 2.9 times of the preprogram. In the low NTD prevalence population, plasma folate increased to 67.9 (44.5, 101.9) nmol/L, which is 1.9 times of the preprogram. Gaps remained in plasma folate levels with respect to prevalence of NTDs and residence. Folic acid supplementation has a strong impact on plasma folate concentrations. Earlier supplementation (before the last menstrual period), increased supplementation frequency and more total days of supplementation were associated with a higher plasma folate concentration as demonstrated in both the high- and low-prevalence populations. CONCLUSION: Plasma folate levels among pregnant Chinese women increased dramatically after the nation-wide folic acid supplementation program in both rural and urban areas, and in populations of high and low NTD prevalence. The nation-wide program should have a component to ensure that supplementation begins before pregnancy.

Maternal obesity, caesarean delivery and caesarean delivery on maternal request: a cohort analysis from China.

BACKGROUND: To quantify the association between maternal obesity and caesarean delivery, particularly caesarean delivery on maternal request (CDMR), a fast-growing component of caesarean delivery in many nations. METHODS: We followed 1,019,576 nulliparous women registered in the Perinatal Healthcare Surveillance System during 1993-2010. Maternal body mass index (BMI, kg/m(2) ), before pregnancy or during early pregnancy, was classified as underweight (<18.5), normal (18.5 to <23; reference), overweight (23 to <27.5), or obese (≥27.5), consistent with World Health Organization guidelines for Asian people. The association between maternal obesity and overall caesarean and its subtypes was modelled using log-binomial regression. RESULTS: During the 18-year period, 404,971 (39.7%) caesareans and 93,927 (9.2%) CDMRs were identified. Maternal obesity was positively associated with overall caesarean and CDMR. Adjusted risk ratios for overall caesarean in the four ascending BMI categories were 0.96 [95% confidence interval (CI) 0.94, 0.97], 1.00 (Reference), 1.16 [95% CI 1.14, 1.18], 1.39 [95% CI 1.43, 1.54], and for CDMR were 0.95 [95% CI 0.94, 0.96], 1.00 (Reference), 1.20 [95% CI 1.18, 1.22], 1.48 [95% CI 1.433, 1.54]. Positive associations were consistently found in women residing in southern and northern provinces and in subgroups stratified by year of delivery, urban or rural residence, maternal age, education, level of delivering hospital, and birthweight. CONCLUSIONS: In a large Chinese cohort study, maternal obesity was associated with an increased risk of caesarean delivery and its subtypes, including CDMR. Given the rising global prevalence of obesity, and in view of the growth of CDMR, it seems likely that caesarean births will increase, unless there are changes in obstetrical practice.