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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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objective: To provide updated information about demographic variations and temporal trends in the prenatal use of multiple micronutrient (MMN) supplements in the metropolitan areas of China.Design: Descriptive analysis of routine prenatal healthcare data between 2013 and 2017.Setting: Chaoyang District, Beijing, China.Participants: A total of 197 346 pregnant women who attended their first prenatal care visit and provided information about MMN supplementation during the periconceptional period.Results: Of these pregnant women, 60·6 % reported consuming prenatal MMN supplements. In multivariate-adjusted models, there were significant gradients of age, education and parity in prenatal MMN supplementation, with the highest likelihood of MMN use among the oldest, the most highly educated and nulliparous women (Pfor trend < 0·001). Compared with that among unemployed women, prenatal MMN supplementation was more common among the employed, especially those engaged in business (adjusted relative risks (95 % CI): 1·08 (1·06, 1·10)) and management (1·10 (1·08, 1·12)). The proportion of prenatal MMN supplementation was 57·0 % in 2013, which increased to 63·5 % in 2017 (Pfor trend < 0·001). The trends varied by age, education and parity (Pfor heterogeneity < 0·001), whereas no significant difference was observed in trends across subgroups of ethnicity or occupation. The greatest magnitude increase in MMN supplement use occurred in women of age < 25 years (annual percent change: 5·7 %), less than high school education (9·6 %), parity ≥ 2 (6·8 %) or unemployment (6·1 %).Conclusion: Approximately two-thirds of women consumed prenatal MMN supplements during the periconceptional period in the central area of Beijing and the proportion increased over time, indicating a need to evaluate the effectiveness and safety and to develop a guideline for relatively well-nourished women. [ABSTRACT FROM AUTHOR]

Excessive gestational weight gain (GWG) increases the risk of maternal anaemia during pregnancy, but whether it is associated with offspring anaemia has not been investigated. We aimed to prospectively investigate the association of GWG rate in the second/third trimester with infant Hb concentration and anaemia risk. The present study comprised 13 765 infants born during 2006–2009 to mothers who participated in a trial on prenatal micronutrient supplementation. The GWG was calculated by subtracting the maternal weight at enrolment from that at end-pregnancy. The GWG rate was calculated as dividing the GWG by number of weeks between the two measurements and classified into quintiles within each category of maternal BMI. Infant Hb concentrations were measured at 6 and 12 months of age, and anaemia was defined as an Hb concentration <110 g/l. Of the 13 765 infants, 949 (6·9 %) were anaemic at 6 months and 728 (5·3 %) at 12 months. The GWG rate was inversely and linearly associated with the infant Hb concentrations at both 6 and 12 months (P < 0·001 for linearity). Compared with the middle quintile of GWG rate, the highest quintile was associated with an increased risk of anaemia at 6 months (adjusted OR 1·30, 95 % CI 1·07, 1·59) and 12 months (adjusted OR 1·74, 95 % CI 1·40, 2·17). The associations were consistently mediated by maternal anaemia during pregnancy (P < 0·001). In conclusion, excessive GWG rate appears to be associated with an increased risk of infant anaemia, partly independent of maternal anaemia during pregnancy that mediates the association. [ABSTRACT FROM AUTHOR]

Both inadequate and excessive gestational weight gain (GWG) have been shown to increase the risk of adverse pregnancy outcomes, but the risk profiles of GWG rate are unclear. We aimed to examine the associations between GWG rate in the second/third trimester and a spectrum of pregnancy outcomes. This study consisted of 14 219 Chinese rural nulliparous women who participated in a randomised controlled trial of prenatal micronutrient supplementation during 2006–2009. The outcomes included stillbirth, neonatal and infant death, preterm birth, macrosomia, low birth weight (LBW) and large and small for gestational age (LGA and SGA, respectively). GWG rate was divided into quintiles within each BMI category. Compared with women in the middle quintile, those in the lowest quintile had higher risks of neonatal death (adjusted OR 2·27; 95 % CI 1·03, 5·02), infant death (adjusted OR 1·85; 95 % CI 1·02, 3·37) and early preterm birth (adjusted OR 2·33; 95 % CI 1·13, 4·77), while those in the highest quintile had higher risks of overall preterm birth (adjusted OR 1·28; 95 % CI 1·04, 1·59), late preterm birth (adjusted OR 1·25; 95 % CI 1·00, 1·56), LBW (adjusted OR 1·48; 95 % CI 1·02, 2·15), macrosomia (adjusted OR 1·89; 95 % CI 1·46, 2·45) and LGA (adjusted OR 1·56; 95 % CI 1·31, 1·85). In conclusion, very low and very high GWG rates in the second/third trimester appear to be associated with adverse pregnancy outcomes in Chinese nulliparous women, indicating that an appropriate GWG rate during pregnancy is necessary for neonatal health. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Concerns have been raised about the benefits of Fe-containing supplements on infant birth weight among women with normal/high Hb levels at baseline. Thus far, no clinical trials have examined whether the effects of prenatal Fe-containing supplements on birth weight vary by maternal Hb levels. We compared the effects of Fe–folic acid (IFA) or multiple micronutrients (MMN) with folic acid (FA) supplements on birth weight among pregnant women with mild/no anaemia or high Hb levels. A double-blind randomised controlled trial was conducted in 2006–2009. In total, 18 775 pregnant women with mild/no anaemia (<100 g/l) were enrolled from five counties in north China. During the period from before 20 weeks of gestation to delivery, the women randomly received a daily supplement containing the following: (1) FA (400 μg); (2) IFA (FA, 400 μg; Fe, 30 mg); or (3) MMN (FA, Fe and thirteen additional vitamins and minerals). Birth weight was measured within the 1st hour of birth. Maternal Hb concentration was determined at enrolment. Among women with normal (≤132 g/l) or high (133–145 g/l) baseline Hb levels, IFA or MMN supplementation had no effect on birth weight. Among women with very high (>145 g/l) baseline Hb levels, IFA and MMN supplements increased birth weight by 91·44 (95 % CI 3·37, 179·51) g and 107·63 (95 % CI 21·98, 193·28) g (P<0·05), respectively, compared with the FA group. No differences were found between the IFA and the MMN group, regardless of maternal Hb concentration. In conclusion, the effects of Fe-containing supplements on birth weight depended on baseline Hb concentrations. The Fe-containing supplements improved birth weight in women with very high Hb levels before 20 weeks of gestation. [ABSTRACT FROM AUTHOR]

Objective: To understand the periconceptional use of folic acid and its association with selected characteristics in northern China.Design: As part of a population-based case-control study on external structural birth defects, we analysed periconceptional use of folic acid among control mothers.Setting: The study was conducted in four counties (Pingding, Xiyang, Taigu and Zezhou) in Shanxi Province of northern China.Subjects: The subjects in this study were the control mothers, who were interviewed between January 2003 and May 2005.Results: Of the 480 respondent mothers, 49 women (10.2%) reported ever using folic acid supplements, and only 16 women (3.3%) used it periconceptionally. The rates of any use and periconceptional use did not change significantly with study year. Periconceptional use of folic acid was significantly increased among women with more than high school education (odds ratio (OR) = 4.57, P < 0.10), women who were not farmers (OR = 4.72, P < 0.05), women with a history of birth-defect-affected pregnancy (OR = 32.73, P < 0.05) and women who planned their pregnancy (OR = 7.88, P < 0.10).Conclusion: The rate of periconceptional folic acid use was among the lowest of those reported from other countries. More work should be done to improve preconceptional use of folic acid with special attention on less educated women and women farmers. [ABSTRACT FROM AUTHOR]

Objective: To report the prevalence of anaemia by demographic characteristics and its secular trend over 13 years for south-east Chinese pregnant women, and to determine the focus of anaemia prevention in Chinese pregnant women., Design: Prospective study of the data on Hb concentration and other demographic information from a large-scale population-based perinatal health surveillance system in south-east China., Setting: Fourteen cities or counties in Jiangsu and Zhejiang provinces., Subjects: A total of 467 057 prenatal women who had participated in the perinatal health-care surveillance system and delivered babies from 1 January 1993 to 31 December 2005 and had a record of Hb in all three pregnancy trimesters., Results: The overall prevalence of anaemia among pregnant women was 39.6 % from 1993 to 2005. Anaemia prevalence increased from the first (29.6 %) to the second (33.0 %) and third (56.2 %) trimesters. The prevalence of anaemia was higher in villagers, in women with less education and in women with higher gravidity or parity. The prevalence of anaemia in all of the trimesters was higher in the spring, summer and autumn and lower in the winter. The prevalence decreased from 1993 to 2005, from 53.3 % to 11.4 % for the first trimester, 45.6 % to 22.8 % for the second trimester and 64.6 % to 44.6 % for the third trimester., Conclusions: The prevalence of anaemia among pregnant women in Jiangsu and Zhejiang provinces decreased substantially from 1993 to 2005. However, anaemia in the third trimester is still a severe public health problem among pregnant women in these areas.