Shaoping Yang

Pre-Pregnancy Body Mass Index, Gestational Weight Gain, and Birth Weight: A Cohort Study in China

Objective To assess whether pre-pregnancy body mass index (BMI) modify the relationship between gestational weight gain (GWG) and child birth weight (specifically, presence or absence of low birth weight (LBW) or presence of absence of macrosomia), and estimates of the relative risk of macrosomia and LBW based on pre-pregnancy BMI were controlled in Wuhan, China. Methods From June 30, 2011 to June 30, 2013. All data was collected and available from the perinatal health care system. Logistic regression models were used to estimate the independent association among pregnancy weight gain, LBW, normal birth weight, and macrosomia within different pre-pregnancy BMI groups. We built different logistic models for the 2009 Institute of Medicine (IOM) Guidelines and Chinese-recommended GWG which was made from this sample. The Chinese-recommended GWG was derived from the quartile values (25th-75th percentiles) of weight gain at the time of delivery in the subjects which comprised our sample. Results For LBW children, using the recommended weight gain of the IOM and Chinese women as a reference, the OR for a pregnancy weight gain below recommendations resulted in a positive relationship for lean and normal weight women, but not for overweight and obese women. For macrosomia, considering the IOM’s recommended weight gain as a reference, the OR magnitude for pregnancy weight gain above recommendations resulted in a positive correlation for all women. The OR for a pregnancy weight gain below recommendations resulted in a negative relationship for normal BMI and lean women, but not for overweight and obese women based on the IOM recommendations, significant based on the recommended pregnancy weight gain for Chinese women. Of normal weight children, 56.6% were above the GWG based on IOM recommendations, but 26.97% of normal weight children were above the GWG based on Chinese recommendations. Conclusions A GWG above IOM recommendations might not be helpful for Chinese women. We need unified criteria to classify adult BMI and to expand the sample size to improve representation and to elucidate the relationship between GWG and related outcomes for developing a Chinese GWG recommendation.

Maternal exposure to air pollutant PM2.5 and PM10 during pregnancy and risk of congenital heart defects

Maternal exposure to ambient air pollution has increasingly been linked to congenital heart defects (CHDs). The objective of this study was to evaluate whether high levels of maternal exposure to PM2.5 and PM10 are related to increased risk of CHDs in Wuhan, China. We conducted a cohort study with a total of 105,988 live-born infants, stillbirths, and fetal deaths. The study included mothers living in the urban district of Wuhan during pregnancy over the 2-year period from 10 June 2011 to 9 June 2013. For each study participant, we assigned 1-month and 1-week averages of PM10 and PM2.5 exposure based on measurements obtained from the nearest exposure monitor to the living residence of mothers during their early pregnancy period. Logistic regression analyses were conducted to calculate the adjusted odds ratios (aORs) and 95% confidence intervals (CI) for the association between exposure to these ambient air pollutants during early pregnancy and CHDs. We observed an increased risk of CHDs, particularly ventricular septal defect (VSD), with increasing PM2.5 exposure. Using 1-week averages, we also observed significant monotonically increasing associations between PM2.5 exposure during weeks 7–10 of pregnancy and risk of VSD, with aORs ranging from 1.11 to 1.17 (95% CI: 1.02–1.20, 1.03–1.22, 1.05–1.24, and 1.08–1.26 separately) per a 10 μg/m3 change in PM2.5 concentration. Our study contributes to the small body of knowledge regarding the association between in utero exposure to air pollution and CHDs, but confirmation of these associations will be needed in future studies.

Pre-Pregnancy BMI, Gestational Weight Gain, and the Risk of Hypertensive Disorders of Pregnancy: A Cohort Study in Wuhan, China

Background Hypertensive disorders of pregnancy (HDP) are major causes of maternal death worldwide and the risk factors are not fully understood. Few studies have investigated the risk factors for HDP among Chinese women. A cohort study involving 84,656 women was conducted to investigate pre-pregnancy BMI, total gestational weight gain (GWG), and GWG during early pregnancy as risk factors for HDP among Chinese women. Methods The study was conducted between 2011–2013 in Wuhan, China, utilizing data from the Maternal and Children Healthcare Information Tracking System of Wuhan. A total of 84,656 women with a live singleton pregnancy were included. Multiple unconditional logistic regression was conducted to evaluate associations between putative risk factors and HDP. Results Women who were overweight or obese before pregnancy had an elevated risk of developing HDP (overweight: OR = 2.66, 95% CI = 2.32–3.05; obese: OR = 5.53, 95% CI = 4.28–7.13) compared to their normal weight counterparts. Women with total GWG above the Institute of Medicine (IOM) recommendation had an adjusted OR of 1.72 (95% CI = 1.54–1.93) for HDP compared to women who had GWG within the IOM recommendation. Women with gestational BMI gain >10 kg/m2 during pregnancy had an adjusted OR of 3.35 (95% CI = 2.89–3.89) for HDP, compared to women with a gestational BMI gain <5 kg/m2. The increased risk of HDP was also observed among women with higher early pregnancy (up to 18 weeks of pregnancy) GWG (>600g/wk: adjusted OR = 1.48, 95% CI = 1.19–1.84). Conclusion The results from this study show that maternal pre-pregnancy BMI, early GWG, and total GWG are positively associated with the risk of HDP. Weight control efforts before and during pregnancy may help to reduce the risk of HDP.

Ozone and Other Air Pollutants and the Risk of Congenital Heart Defects

The objective of this study was to evaluate whether high levels of maternal exposure to O3, SO2, NO2, CO are related to increased risk of congenital heart defects (CHDs) in Wuhan, China. The study included mothers living in the central districts of Wuhan during pregnancy over the two-year period from June 10, 2011 to June 9, 2013. For each study participant, we assigned 1-month averages of O3, SO2, NO2 and CO exposure based on measurements obtained from the nearest exposure monitor to the living residence of mothers during their early pregnancy period. In one-pollutant model, we observed an increased risk of CHDs, ventricular septal defect (VSD), and tetralogy of fallot (TF) with increasing O3 exposure. In two-pollutant model, associations with all CHDs, VSD, and TF for O3 were generally consistent compared to the models that included only O3, with the strongest aORs observed for exposures during the third month of pregnancy. We also observed a positive association between CO exposures during the third month of pregnancy and VSD in two pollution model.Our results contribute to the small body of evidence regarding air pollution exposure and CHDs, but confirmation of these associations will be needed in future studies.

Parental Body Mass Index, Gestational Weight Gain, and Risk of Macrosomia: a Population-Based Case–Control Study in China

BACKGROUND The prevalence of macrosomia has risen markedly worldwide, including in China, during the past two decades. Few epidemiological studies, however, have investigated the risk factors for macrosomia in China. This study was designed to investigate the associations between parental anthropometric characteristics, gestational weight gain (GWG), and risk of macrosomia in China. METHODS This population-based, case-control study in Wuhan, China, included a total of 6341 subjects (870 cases and 5471 controls). Multivariable logistic regression was conducted to calculate odds ratios (OR) and 95% confidence intervals (CI). RESULTS Mothers or fathers who were overweight or obese before pregnancy had an elevated risk of giving birth to a macrosomic infant compared with their normal weight counterparts. Women with GWG above the Institute of Medicine (IOM) recommendation had an adjusted OR of 6.09 [95% CI 5.04, 7.35] for delivering a macrosomic infant compared with women who had GWG within the IOM recommendation. When stratified by maternal pre-pregnancy body mass index (BMI), women who were underweight or normal weight before pregnancy were observed to have a higher risk of macrosomia birth associated with greater GWG. CONCLUSIONS Parental pre-pregnancy overweight/obesity and excessive GWG during pregnancy were highly associated with macrosomia. The association with GWG was most pronounced in mothers who had a normal or underweight pre-pregnancy BMI. Weight control efforts before pregnancy for mothers and fathers as well as control of maternal gain during pregnancy may reduce the risk of macrosomia.

Maternal Prepregnancy Body Mass Index and Small for Gestational Age Births in Chinese Women.

BACKGROUND Both high and low prepregnancy body mass index (BMI) has been associated with small for gestational age births (SGA; birthweight below the population specific 10th centile for the gestational age), but results remain inconsistent. We examined the association between maternal BMI and SGA, and evaluated if the associations were modified by preterm birth (being born prior to 37 weeks) status. METHODS A population-based cohort study was conducted in Wuhan, China from June 2011, to June 2013. Women who delivered a non-malformed livebirth (n = 76 695) were included using the Wuhan Maternal and Child Health Management Information System. Log-binomial regression models were used to analyse the associations between prepregnancy BMI, categorized using thresholds adapted to the Chinese population, and SGA. Stratified analyses were used to examine the relationship of prepregnancy BMI to preterm-SGA and term-SGA. RESULTS Of the 76 695 live births, 3058 (4.0%) were delivered preterm. For babies born at term, prepregnancy underweight (<18.5 kg/m2 ) was associated with an increased risk of SGA, the adjusted risk ratio (RR) was 1.41 (95% confidence interval (CI) 1.33, 1.49), whereas, being overweight (24.0-27.9 kg/m2 ) was associated with a decreased risk (RR 0.84, 95% CI 0.74, 0.94). For babies born preterm, prepregnancy underweight was not associated with risk of SGA, but being overweight was associated with an increased risk (RR 1.57, 95% CI 1.04, 2.35). CONCLUSIONS These data suggest that the association of overweight and underweight prepregnancy BMI and SGA differs depending on whether the baby is full term or preterm.

Progress on the Maternal Mortality Ratio Reduction in Wuhan, China in 2001–2012

Background Most maternal deaths occur in developing countries and most maternal deaths are avoidable. China has made a great effort to reduce MMR by three quarters to meet the fifth Millennium Development Goal (MDG5). Methods This retrospective study reviewed and analyzed maternal death data in Wuhan from 2001 to 2012. Joinpoint regression and multivariate Poisson regression was conducted using the log-linear model to measure the association of the number of maternal deaths with time, cause of death, where the death occurred, and cognitive factors including knowledge, attitude, resource, and management stratified. Results The MMR declined from 33.41 per 100,000 live births in 2001 to 10.63 per 100,000 live births in 2012, with a total decline of 68.18% and an average annual decline of 9.89%. From 2001–2012, the four major causes of maternal death were obstetric hemorrhage (35.16%), pregnancy complications (28.57%), amniotic fluid embolism (16.48%) and gestational hypertension (8.79%). Multivariate Poisson regression showed on average the MMR decreased by.17% each year from 2001–2006 and stayed stagnant since 2007–2012. Conclusions With the reduction in MMR in obstetric death (e.g. obstetric hemorrhage), there had been a remarkable reduction in MMR in Wuhan in 2001–2012, which may be due to (1) the improvement in the obstetric quality of perinatal care service on prevention and treatment of obstetric hemorrhage and emergency care skills, and (2) the improvement in the maternal health management and quality of prenatal care. Interventions to further reduce the MMR include several efforts such as the following: (1) designing community-based interventions, (2) providing subsidies to rural women and/hospitals for hospital delivery, (3) screening for pregnancy complications, and (4) establishing an emergency rescue system for critically ill pregnant women.

Ambient air pollution the risk of stillbirth: A prospective birth cohort study in Wuhan, China

BACKGROUND Recent studies suggest that ambient air pollution exposure during pregnancy is associated with stillbirth occurrence. However, the results on the associations between ambient air pollutants and stillbirths are inconsistent and little is known about the gestational timing of sensitive periods for the effects of ambient air pollutants exposure on stillbirth. OBJECTIVE This study aimed to examine whether exposure to high levels of ambient air pollutants in a Chinese population is associated with an increased risk of stillbirth, and determine the gestational period when the fetus is most susceptible. METHODS We conducted a population-based cohort study in Wuhan, China, involving 95,354 births between June 10, 2011 and June 9, 2013. The exposure assessments were based on the daily mean concentrations of air pollutants obtained from the exposure monitor nearest to the pregnant womens residence. Logistic regression analyses were performed to determine the associations between stillbirths and exposure to each of the air pollutants at different pregnancy periods with adjustment for confounding factors. RESULTS Stillbirth increased with a 10 μg/m3 increase in particulate matter 2.5 (PM2.5) in each stage of pregnancy, and a significant association between carbon monoxide (CO) exposure and stillbirth was found during the third trimester (adjusted odds ratio (aOR): 1.01, 95% confidence interval (CI): 1.00-1.01) and in the entire pregnancy (aOR: 1.18, 95% CI: 1.04-1.34). Furthermore, an increased risk of stillbirth in the third trimester was associated with a 10 μg/m3 increase in PM10 (aOR: 1.08, 95% CI: 1.04-1.11), nitrogen dioxide (NO2) (aOR: 1.13, 95% CI: 1.07-1.21) and sulfur dioxide (SO2) (aOR: 1.26, 95% CI: 1.16-1.35). However, no positive association was observed between ozone exposure and stillbirth. In the two-pollutant models, PM2.5 and CO exposures were found to be consistently associated with stillbirth. CONCLUSIONS Our study revealed that exposure to high levels of PM2.5, PM10, SO2, NO2 and CO increases the risk of stillbirth and the most susceptible gestational period to ambient air pollution exposure was in the third trimester. Further toxicological and prospective cohort studies with improved exposure assessments are needed to confirm the causal link between air pollutants and stillbirth.

Symptoms of anxiety and depression during pregnancy and their association with low birth weight in Chinese women: a nested case control study.

This study is a nested case control study from a population-based cohort study conducted in Wuhan, China. The aim is to estimate the association between symptoms of depression during pregnancy (DDP), anxiety during pregnancy(ADP), and depression with anxiety during pregnancy (DADP) and low birth weight (LBW) and to examine the extent to which preterm birth (PTB) moderates these associations. Logistic regression analyses were used to model associations between DDP, ADP, and DADP and LBW. Models were stratified by the presence or absence of PTB to examine moderating effects. From the cohort study, 2853 had a LBW baby (cases); 5457 pregnant women served as controls. Women with DDP or ADP only were not at higher risk of having a LBW baby, but DADP was associated with increased risk of LBW (crude OR 1.41, 95% CI 1.17–1.70; adjusted OR 1.29, 95% CI 1.07–1.57), and the significant association was particularly evident between DADP and LBW in PTB, but not in full-term births. Our data suggests that DADP is related to an increased risk of LBW and that this association is most present in PTBs.

Perinatal risk factors for obstructive sleep apnea syndrome in children

OBJECTIVE The aim of this study was to determine whether specific perinatal factors are associated with obstructive sleep apnea syndrome (OSAS) in children. METHODS A retrospective case-control study was conducted. All cases of OSAS were obtained from a tertiary pediatric hospital between April 2013 and April 2016. A total of 823 children who had been diagnosed with OSAS were designated as the case group, and 823 children without OSAS were selected with strict criteria to match with the case group by age, gender and body mass index. Logistic regression models were used to determine the perinatal factors associated with childhood OSAS. RESULTS Preterm birth (adjusted odds ratio (aOR): 1.87, 95% confidence interval (CI): 1.13-3.08) and cesarean section (aOR: 1.32, 95% CI: 1.03-1.68) were significantly associated with OSAS. Exposure of the mother to smoke (aOR: 2.59, 95% CI: 1.57-4.26) was also associated with an increased risk of childhood OSAS. Mothers aged 35 years and above, performing manual labor, and living in suburban areas significantly increased the risk of childhood OSAS. Multiparous mothers decreased the risk of childhood OSAS (aOR: 0.59, 95% CI: 0.42-0.83). Maternal education, gravidity, prenatal care times, pregnancy-induced hypertension, multiple pregnancies, sex of the child and birth weight were not significantly associated with OSAS in children. CONCLUSION Perinatal risk factors are important for predicting childhood OSAS. Our findings provide evidence regarding several potentially useful factors for recognizing OSAS in children, which could be important in diagnosis of pediatric OSAS by physicians.