Kui Deng

The association between periconceptional folic acid supplementation and congenital heart defects: A case–control study in China

OBJECTIVE This study aims to evaluate the association between folic acid (FA) supplementation and congenital heart defects (CHDs). METHODS This hospital-based case-control study initiated in 2010 in China analyzed 358 cases and 422 controls. The adjusted odds ratio (AOR) calculated using a logistic model was used to assess the association between FA supplementation and CHDs. RESULTS Compared with a mother who reported no FA supplementation, mothers who reported FA supplementation were less likely to have offspring with isolated CHD(s) (AOR=0.52, 0.34-0.78) and multiple complex conditions (AOR=0.27, 0.14-0.55). However, mothers who reported FA supplementation for less than 1 month regardless of the start time of supplementation, did not have a significantly lower risk of having an offspring with isolated or multiple complex conditions. Mothers who reported FA supplementation for ≧3 months beginning before conception had a significantly lower risk of having children with isolated CHD(s) (AOR=0.31, 0.18-0.54). CONCLUSION FA-supplementation is associated with reduced risk of CHDs. The earlier FA supplementation begins before pregnancy and the longer supplementation lasts, the lower the risk of CHDs is.

Periconceptional paternal smoking and the risk of congenital heart defects: A case-control study

BACKGROUND Maternal smoking during pregnancy has been consistently associated with an increased risk of congenital heart defects (CHDs). However, few studies have reported the association between paternal smoking during pregnancy and CHDs among offspring. This report presents the first case-control study to investigate the possible association between periconceptional paternal smoking and CHDs in China. METHODS From February 2010 through October 2011, 284 case fetuses with nonsyndromic CHDs and 422 control fetuses with no birth defects were recruited. The mothers of cases and controls were interviewed regarding whether the fathers of fetuses smoked and avoided the mothers while smoking during the periconceptional period. An unconditional logistic regression was used to calculate the adjusted odds ratios (AORs) and 95% confidence intervals (CIs) while controlling for potential confounders. RESULTS Light paternal smoking increased the risk of isolated conotruncal heart defects (AOR, 2.23; 95% CI, 1.05, 4.73). Medium paternal smoking seemed to be associated with septal defects (AOR, 2.04; 95% CI, 1.05, 3.98) and left ventricular outflow tract obstructions (AOR, 2.48; 95% CI, 1.04, 5.95). Heavy paternal smoking was also associated with isolated conotruncal heart defects (AOR, 8.16; 95% CI, 1.13, 58.84) and left ventricular outflow tract obstructions (AOR, 13.12; 95% CI, 2.55, 67.39). Paternal smoking with no avoidance behavior was associated with an increased risk of these CHDs subtypes. CONCLUSIONS Periconceptional paternal smoking increased the risk of isolated conotruncal heart defects, septal defects and left ventricular outflow tract obstructions. The avoidance behavior of paternal smokers may decrease the risk of selected CHDs.

Epidemiologic characteristics and time trend in the prevalence of anotia and microtia in China.

BACKGROUND Previous studies have shown an inconsistent time trend on the prevalence of anotia and microtia. Little has been reported on the epidemiologic characteristics of anotia and microtia in the Chinese population. METHODS Data from 1996-2007 were obtained from the Chinese Birth Defects Monitoring Network in China. Birth prevalence of anotia and microtia were assessed according to demographic characteristics and annual time trend. Poisson regression was used to calculate crude and adjusted prevalence ratios (APRs) and 95% confidence intervals (CIs) for selected demographic characteristics and subgroups of anotia and microtia. RESULTS A total of 1933 cases with anotia/microtia were identified among 6,308,594 live births, stillbirths, and terminations of pregnancy, yielding a rate of 3.06 per 10,000 births. Isolated anotia/microtia had a prevalence of 2.25 per 10,000 births, whereas among nonisolated cases, the prevalence was 0.81 per 10,000 births. The prevalence rates of anotia/microtia increased significantly during 1996-2007 (p < 0.05). Birth prevalence of isolated anotia/microtia was significantly higher among western births (APR, 1.24; 95% CI, 1.10-1.40), mothers residing in urban areas (APR, 1.29; 95% CI, 1.15-1.46), mothers more than 35 years of age (APR, 1.26; 95% CI, 1.01-1.57), and males (APR, 1.38; 95% CI, 1.24-1.53). No significant associations were observed between nonisolated anotia/microtia and geographic areas, maternal residence, and infant sex (except for maternal age). CONCLUSION An increasing trend of the birth prevalence of anotia and microtia is observed in China. Higher prevalence risk of isolated anotia and microtia is found among western births, mothers residing in urban areas, older mothers, and males.

Sociodemographic and obstetric characteristics of stillbirths in China: a census of nearly 4 million health facility births between 2012 and 2014

BACKGROUND Very little is known about the burden and determinants of stillbirths in China. We used data from a national surveillance system for health facility births to compute a stillbirth rate representative of all facility births in China and to explore sociodemographic and obstetric factors associated with variation in the stillbirth rate. METHODS We used data from Chinas National Maternal Near Miss Surveillance System between Jan 1, 2012, and Dec 31, 2014, which covers 441 hospitals in 326 urban districts and rural counties. The surveillance aimed to enumerate all maternal deaths and near misses in health facilities, and collected data prospectively for all pregnant or post-partum women admitted to the obstetric department. We restricted the analysis to births of 28 or more completed weeks of gestation or 1000 g or heavier birthweight. We examined the strength of association between sociodemographic characteristics, gestational age, and obstetric complications and stillbirths using logistic regression, taking account of the sampling strategy and clustering of births within hospitals and in cases of more than one birth per woman. FINDINGS There were 3 956 836 births and 37 855 stillbirths, giving a stillbirth rate of 8·8 per 1000 births (95% CI 8·8-8·9). The stillbirth rate was particularly high for women younger than 15 years of age (59·9 stillbirths per 1000 births), those who had not sought antenatal care (38·3 per 1000), the unmarried (32·5 per 1000), those with no education (26·9 per 1000), or those who had had four or more births (23·2 per 1000). A high proportion (29 319 [78·2%] of 37 514) of stillbirths occurred at gestational ages of younger than 37 weeks, and about two thirds (24 787 [66·1%] of 37 514) were in women without any maternal complication at the time of birth. Of babies born at normal gestations (37-41 weeks), maternal complications substantially increased the risk of stillbirth (odds ratio comparing antepartum or intrapartum complications with no complication 3·96 [95% CI 3·66-4·29]), but only a small proportion (1638 [4·4%] of 37 514) of stillbirths fell into this group. INTERPRETATION Our analysis of nearly 4 million births in 441 health facilities in China suggests a stillbirth rate of 8·8 per 1000 births between 2012 and 2014. Stillbirths do not feature in the Chinese Governments 5 year plans and most information systems do not include stillbirths. The Government need to start paying attention to stillbirths and invest strategically in antenatal care, particularly for the most disadvantaged women, including the very young, unmarried, and illiterate, and those at high parity. FUNDING National Health and Family Planning Commission of the Peoples Republic of China, National Natural Science Foundation of China, China Medical Board, WHO, and UNICEF.

Modification of the association between maternal smoke exposure and congenital heart defects by polymorphisms in glutathione S-transferase genes.

Congenital heart defects (CHDs) arise through various combinations of genetic and environmental factors. Our study explores how polymorphisms in the glutathione S-transferase (GST) genes affect the association between cigarette smoke exposure and CHDs. We analysed 299 mothers of children with CHDs and 284 mothers of children without any abnormalities who were recruited from six hospitals. The hair nicotine concentration (HNC) was used to quantify maternal smoke exposure, and the maternal GSTT1, and GSTM1 and GSTP1 genes were sequenced. We found a trend of higher adjusted odds ratios with higher maternal HNC levels, suggesting a dose-response relationship between maternal smoke exposure and CHDs. The lowest HNC range associated with an increased risk of CHDs was 0.213–0.319 ng/mg among the mothers with functional deletions of GSTM1 or GSTT1and 0.319–0.573 ng/mg among the mothers with normal copies of GSTM1 and GSTT1. In addition, the adjusted odds ratio for an HNC of >0.573 ng/mg was 38.53 among the mothers with the GSTP1 AG or GG genotype, which was 7.76 (χ2 = 6.702, p = 0.010) times greater than the AOR in the mothers with GSTP1 AA genotype. Our study suggests that polymorphisms of maternal GST genes may modify the association of maternal smoke exposure with CHDs.

Relaxation of the one child policy and trends in caesarean section rates and birth outcomes in China between 2012 and 2016: observational study of nearly seven million health facility births

Abstract Objective To examine how the relaxation of the one child policy and policies to reduce caesarean section rates might have affected trends over time in caesarean section rates and perinatal and pregnancy related mortality in China. Design Observational study. Setting China’s National Maternal Near Miss Surveillance System (NMNMSS). Participants 6 838 582 births at 28 completed weeks or more of gestation or birth weight ≥1000 g in 438 hospitals in the NMNMSS between 2012 and 2016. Main outcome measures Obstetric risk was defined using a modified Robson classification. The main outcome measures were changes in parity and age distributions and relative frequency of each Robson group, crude and adjusted trends over time in caesarean section rates within each risk category (using Poisson regression with a robust variance estimator), and trends in perinatal and pregnancy related mortality over time. Results Caesarean section rates declined steadily between 2012 and 2016 (crude relative risk 0.91, 95% confidence interval 0.89 to 0.93), reaching an overall hospital based rate of 41.1% in 2016. The relaxation of the one child policy was associated with an increase in the proportion of multiparous births (from 34.1% in 2012 to 46.7% in 2016), and births in women with a uterine scar nearly doubled (from 9.8% to 17.7% of all births). Taking account of these changes, the decline in caesarean sections was amplified over time (adjusted relative risk 0.82, 95% confidence interval 0.81 to 0.84). Caesarean sections declined noticeably in nulliparous women (0.75, 0.73 to 0.77) but also declined in multiparous women without a uterine scar (0.65, 0.62 to 0.77). The decrease in caesarean section rates was most pronounced in hospitals with the highest rates in 2012, consistent with the government’s policy of targeting hospitals with the highest rates. Perinatal mortality declined from 10.1 to 7.2 per 1000 births over the same period (0.87, 0.83 to 0.91), and there was no change in pregnancy related mortality over time. Conclusions China is the only country that has succeeded in reverting the rising trends in caesarean sections. China’s success is remarkable given that the changes in obstetric risk associated with the relaxation of the one child policy would have led to an increase in the need for caesarean sections. China’s experience suggests that change is possible when strategies are comprehensive and deal with the system level factors that underpin overuse as well as the various incentives at work during a clinical encounter.

Maternal exposure to ambient PM 10 during pregnancy increases the risk of congenital heart defects: Evidence from machine learning models

Previous research suggested an association between maternal exposure to ambient air pollutants and risk of congenital heart defects (CHDs), though the effects of particulate matter ≤10μm in aerodynamic diameter (PM10) on CHDs are inconsistent. We used two machine learning models (i.e., random forest (RF) and gradient boosting (GB)) to investigate the non-linear effects of PM10 exposure during the critical time window, weeks 3-8 in pregnancy, on risk of CHDs. From 2009 through 2012, we carried out a population-based birth cohort study on 39,053 live-born infants in Beijing. RF and GB models were used to calculate odds ratios for CHDs associated with increase in PM10 exposure, adjusting for maternal and perinatal characteristics. Maternal exposure to PM10 was identified as the primary risk factor for CHDs in all machine learning models. We observed a clear non-linear effect of maternal exposure to PM10 on CHDs risk. Compared to 40μgm-3, the following odds ratios resulted: 1) 92μgm-3 [RF: 1.16 (95% CI: 1.06, 1.28); GB: 1.26 (95% CI: 1.17, 1.35)]; 2) 111μgm-3 [RF: 1.04 (95% CI: 0.96, 1.14); GB: 1.04 (95% CI: 0.99, 1.08)]; 3) 124μgm-3 [RF: 1.01 (95% CI: 0.94, 1.10); GB: 0.98 (95% CI: 0.93, 1.02)]; 4) 190μgm-3 [RF: 1.29 (95% CI: 1.14, 1.44); GB: 1.71 (95% CI: 1.04, 2.17)]. Overall, both machine models showed an association between maternal exposure to ambient PM10 and CHDs in Beijing, highlighting the need for non-linear methods to investigate dose-response relationships.

Long-term trends and seasonality of omphalocele during 1996–2010 in China: a retrospective analysis based on the hospital-based birth defects surveillance system

BackgroundLittle is known about secular trends and seasonal variation in the birth prevalence of omphalocele in China. This study aimed to explore the long-term trends and seasonality of this birth defect, to provide insight into the etiology and prevention of omphalocele.MethodsA retrospective analysis of all births with omphalocele (1322 cases in 8.8 million births) registered in the hospital-based Chinese Birth Defects Monitoring Network between January 1996 and September 2010. Negative binomial cyclical regression models were used to analyze the long-term trends and seasonal fluctuations of omphalocele occurrence in the southern and northern regions and urban and rural areas of China.ResultsThe total prevalence of omphalocele was 1.50 cases (95% confidence interval (CI): 1.42–1.58) per 10,000 births. There was no significant secular trend of omphalocele occurrence in China between 1996 and 2010. The observed prevalence of omphalocele in rural areas was 2.03–2.54 cases per 10,000 births between May and August, which was higher than that observed in other months. The highest prevalence of births with omphalocele in rural areas occurred at the end of June; on average, the prevalence of omphalocele at that time point increased by 20% (95% CI: 6–35%) compared with other months.ConclusionsThere were no long-term trends found for occurrence of omphalocele in China between 1996 and 2010; however, seasonality was observed for omphalocele in women living in rural areas. These results may help generate hypotheses for further study of environmental factors that vary by season.

Incidence of congenital hypothyroidism in China: data from the national newborn screening program, 2013–2015

Abstract Background: Congenital hypothyroidism (CH) is one of the most frequent, preventable causes of mental retardation. Little has been reported on the epidemiological characteristics of CH in China. We aimed to estimate the incidence of CH in China and investigate its geographical variation. Methods: We analyzed data from the nationwide newborn screening program for CH between 2013 and 2015. Poisson regression was used to generate the odds ratios (ORs) and 95% confidence intervals (CIs) between the rates of CH and selected demographic characteristics and assess the potential association between CH incidence and geographical locations. Results: A total of 18,666 patients with CH were identified from 45.2 million newborns, yielding an overall incidence rate of 4.13 per 10,000 live births. Compared with those in the remote area, regardless of infant sex, a higher incidence risk for CH was present in newborns in coastal areas and inland areas (females: OR=2.00, 95% CI: 1.86–2.16 and OR=1.74, 95% CI: 1.61–1.87, respectively; males: OR=1.70, 95% CI: 1.59–1.83 and OR=1.52, 95% CI: 1.42–1.63, respectively). Additionally, the highest risk of CH for thyroid-stimulating hormone (TSH) screening values <40 mU/L was observed among neonates in the coastal areas, while TSH screening values of 70–100 mU/L were observed among those in the inland areas. Conclusions: The overall incidence of CH is high in China. The significant geographical variations of CH incidence are presented in this study.