Impact of cesarean section on metabolic syndrome components in offspring rats.

INTRODUCTION: Epidemiological evidence suggests an association between CS and offspring metabolic syndrome (MetS), but whether a causal relationship exists is unknown. METHODS: In this study, timed-mated Wistar rat dams were randomly assigned to cesarean section (CS), vaginal delivery (VD), and surrogate groups. The offspring from both CS and VD groups were reared by surrogate dams until weaning, and weaned male offspring from both groups were randomly assigned to receive normal diet (ND) or high-fat/high-fructose diet (HFF) ad libitum for 39 weeks. RESULTS: By the end of study, CS-ND offspring gained 17.8% more weight than VD-ND offspring, while CS-HFF offspring gained 36.4% more weight than VD-HFF offspring. Compared with VD-ND offspring, CS-ND offspring tended to have increased triglycerides (0.27 mmol/l, 95% CI, 0.05 to 0.50), total cholesterol (0.30 mmol/l, -0.08 to 0.68), and fasting plasma glucose (FPG) (0.30 mmol/l, -0.01 to 0.60); more pronounced differences were observed between CS-HFF and VD-HFF offspring in these indicators (triglyceride, 0.66 mmol/l, 0.35 to 0.97; total cholesterol, 0.46 mmol/l, 0.13 to 0.79; and FPG, 0.55 mmol/l, 0.13 to 0.98). CONCLUSIONS: CS offspring were more prone to adverse metabolic profile and HFF might exacerbate this condition, indicating the association between CS and MetS is likely to be causal. IMPACT: Whether the observed associations between CS and MetS in non-randomized human studies are causally relevant remains undetermined. Compared with vaginally born offspring rats, CS born offspring gained more body weight and tended to have compromised lipid profiles and abnormal insulin sensitivity, suggesting a causal relationship between CS and MetS that may be further amplified by a high-fat/high-fructose diet. Due to the high prevalence of CS births globally, greater clinical consideration must be given to the potential adverse effects of CS, and whether these risks should be made known to patients in clinical practice merits evaluation.

Association of caesarean delivery with offspring health outcomes in full-cohort versus sibling-comparison studies: a comparative meta-analysis and simulation study.

BACKGROUND: Full-cohort and sibling-comparison designs have yielded inconsistent results about the impacts of caesarean delivery on offspring health outcomes, with the effect estimates from the latter being more likely directed towards the null value. We hypothesized that the seemingly conservative results obtained from the sibling-comparison design might be attributed to inadequate adjustment for non-shared confounders between siblings, particularly maternal age at delivery. METHODS: A systematic review and meta-analysis was first conducted. PubMed, Embase, and the Web of Science were searched from database inception to April 6, 2022. Included studies (1) examined the association of caesarean delivery, whether elective or emergency, with offspring health outcomes; (2) simultaneously conducted full-cohort and sibling-comparison analyses; and (3) reported adjusted effect estimates with 95% confidence intervals (95% CIs). No language restrictions were applied. Data were extracted by 2 reviewers independently. Three-level meta-analytic models were used to calculate the pooled odds ratios (ORs) and 95% CIs for caesarean versus vaginal delivery on multiple offspring health outcomes separately for full-cohort and sibling-comparison designs. Subgroup analyses were performed based on the method of adjustment for maternal age at delivery. A simulation study was then conducted. The simulated datasets were generated with some key parameters derived from the meta-analysis. RESULTS: Eighteen studies involving 21,854,828 individuals were included. The outcomes assessed included mental and behavioral disorders; endocrine, nutritional and metabolic diseases; asthma; cardiorespiratory fitness; and multiple sclerosis. The overall pooled OR for estimates from the full-cohort design was 1.14 (95% CI: 1.11 to 1.17), higher than that for estimates from the sibling-comparison design (OR = 1.08; 95% CI: 1.02 to 1.14). Stratified analyses showed that estimates from the sibling-comparison design varied considerably across studies using different methods to adjust for maternal age at delivery in multivariate analyses, while those from the full-cohort design were rather stable: in studies that did not adjust maternal age at delivery, the pooled OR of full-cohort vs. sibling-comparison design was 1.10 (95% CI: 0.99 to 1.22) vs. 1.06 (95% CI: 0.85 to 1.31), in studies adjusting it as a categorical variable, 1.15 (95% CI: 1.11 to 1.19) vs. 1.07 (95% CI: 1.00 to 1.15), and in studies adjusting it as a continuous variable, 1.12 (95% CI: 1.05 to 1.19) vs. 1.12 (95% CI: 0.98 to 1.29). The severe underestimation bias related to the inadequate adjustment of maternal age at delivery in sibling-comparison analyses was fully replicated in the simulation study. CONCLUSIONS: Sibling-comparison analyses may underestimate the association of caesarean delivery with multiple offspring health outcomes due to inadequate adjustment of non-shared confounders, such as maternal age at delivery. Thus, we should be cautious when interpreting the seemingly conservative results of sibling-comparison analyses in delivery-related studies.

Geographic variations and determinants of EPA plus DHA and EPA alone in pregnant and lactating women from China.

EPA and DHA are essential for maternal and fetal health, but epidemiological data are sparse in China. We examined the trends of EPA alone and a combination of EPA plus DHA in pregnant and lactating women in three distinct geographic regions in China and explored their potential influencing factors. A total of 1015 healthy women during mid-pregnancy, late pregnancy or lactation were recruited from Weihai (coastland), Yueyang (lakeland) and Baotou (inland) cities of China between May and July of 2014. Maternal EPA and DHA concentrations (percentage of total fatty acids) in plasma and erythrocytes were measured by capillary GC. Adjusted EPA plus DHA concentrations in both plasma and erythrocytes significantly declined from mid-pregnancy (2·92 %, 6·95 %) to late pregnancy (2·20 %, 6·42 %) and lactation (2·40 %, 6·29 %) (Ptrend < 0·001); and both concentrations were highest in coastland, followed by lakeland, and lowest in inland (P < 0·001). Regarding EPA alone, the concentrations were higher in women during lactation or late pregnancy and in women in coastland and inland areas. Moreover, concentrations of EPA or EPA plus DHA were higher in women with older age, higher education, higher annual family income per capita and higher dietary intake of marine aquatic product and mutton. In lactating women, erythrocyte EPA concentration was higher in those having breast-feeding partially v. exclusively. In conclusion, maternal plasma and erythrocyte concentrations of EPA plus DHA or EPA alone differed with geographic regions, physiological periods and maternal characteristics, indicating a need of population-specific health strategies to improve fatty acids status in pregnant and lactating women.

Long-pulsed neodymium-doped yttrium-aluminum-garnet laser versus cryotherapy for the treatment of cutaneous warts: A randomized controlled trial.

BACKGROUND: Observational studies have shown promising therapeutic effects of long-pulsed neodymium-doped yttrium-aluminum-garnet (LP-Nd:YAG) laser on warts. OBJECTIVE: To evaluate whether LP-Nd:YAG laser was superior to cryotherapy for cutaneous warts. METHODS: In this study, 150 adult patients with warts were randomized equally to receive laser or cryotherapy every 3 to 4 weeks, for a maximum of 4 sessions. The primary outcomes were the cure rates at 16 weeks and 6 months; secondary outcomes included time to clearance of warts and treatment-related adverse effects. RESULTS: There was no difference in the cure rate for laser versus cryotherapy at 16 weeks (54.1% vs 46.7%, respectively) and 6 months (59.5% vs 57.3%, respectively). However, time to clearance of warts, up to 16 weeks and 6 months, tended to be shorter for laser versus cryotherapy (P = .04 and .08, respectively). Post hoc analyses showed a significantly higher cure rate for laser versus cryotherapy in 3 subgroups of human papillomavirus 2/27/57-induced recalcitrant warts but not in their counterpart subgroups. Laser had more mild adverse effects. LIMITATIONS: Single center. CONCLUSIONS: The overall therapeutic effects of LP-Nd:YAG laser were similar to cryotherapy, but laser may be more effective to relatively recalcitrant warts and may be associated with shorter time to clearance of warts.

Geographic and socio-demographic determinants of plasma retinol concentrations in Chinese pregnant and lactating women.

PURPOSE: To examine plasma retinol status and its determinants in Chinese pregnant or lactating women. METHODS: A cross-sectional study involving 1211 healthy women in mid-pregnancy, late pregnancy, or lactation was conducted in northern, central, and southern China. Plasma retinol concentration was determined by high-performance liquid chromatography. Multivariate quantile regression or modified Poisson regression was used to estimate adjusted medians, or to examine the associations of suboptimal retinol concentration (< 1.05 µmol/L) with various factors. RESULTS: The overall median (interquartile range) retinol concentration was 1.25 (1.06-1.46) µmol/L. The adjusted concentration was higher in women at lactation (1.39 [1.20-1.63] µmol/L) and mid-pregnancy (1.26 [1.10-1.44] µmol/L) than late pregnancy (1.07 [0.92-1.28] µmol/L), and higher in women in the central area (1.34 [1.18-1.49] µmol/L) and the north (1.26 [1.10-1.43] µmol/L) than the south (1.19 [1.07-1.31] µmol/L). The retinol concentration was more likely to be low in women with lower pre-pregnancy BMI, younger age, less education, and in lactating women who had a caesarean birth or were breastfeeding exclusively. A total of 290 (24.0%) women had a suboptimal retinol concentration, and the prevalence was higher in women at late pregnancy, residing in the south, with younger age, and having underweight pre-pregnancy. CONCLUSION: About one-fourth of pregnant or lactating women in China had suboptimal retinol concentrations that varied with phases of pregnancy and lactation, region of residence, and socio-demographic characteristics, indicating a need for population-specific public health strategies to optimize vitamin A status.

Preterm delivery rate in China: a systematic review and meta-analysis.

BACKGROUND: Preterm delivery rate is a crucial public health indicator, yet reliable statistic is currently not available in China. In this systematic review and meta-analysis, we aimed to review studies on preterm delivery rate in China, explore sources of heterogeneity, and estimate the preterm delivery rate in China. METHODS: Published studies on preterm delivery rate in China since 2010 were electronically searched from PubMed, Embase, Web of Science, China National Knowledge Infrastructure, China Science and Technology Journal Database, and Wanfang Database, and complemented by manual search. Study selection, data extraction, and quality and bias assessment (using the Joanna Briggs Institute Critical Appraisal Checklist) were conducted by two reviewers independently. Random-effects meta-analysis was performed to estimate the pooled preterm delivery rate, and prespecified stratified analysis was conducted to explore sources of heterogeneity. RESULTS: The database search returned 4494 articles and manual search identified 10 additional studies. In total, 162 studies were eligible, of which 124 were hospital-based and 38 population-based. The pooled preterm delivery rate of hospital-based studies (7.2%; 95% CI: 6.9% to 7.6%) was significantly higher than that of population-based studies (4.9%; 95% CI: 4.5% to 5.4%) (P for subgroup difference < 0.001). Among population-based studies, the rate tended to differ by geography (P for subgroup difference = 0.07): 5.3% for Eastern, 4.6% for Central, and 3.8% for Western. CONCLUSIONS: According to population-based studies, the preterm delivery rate in China is around 5%. This rate is substantially lower than estimates from hospital-based studies or estimates from a combination of both hospital-based and population-based studies as having been done in previous studies.

Trends and influencing factors of plasma folate levels in Chinese women at mid-pregnancy, late pregnancy and lactation periods.

Folate status for women during early pregnancy has been investigated, but data for women during mid-pregnancy, late pregnancy or lactation are sparse or lacking. Between May and July 2014, we conducted a cross-sectional study in 1211 pregnant and lactating women from three representative regions in China. Approximately 135 women were enrolled in each stratum by physiological periods (mid-pregnancy, late pregnancy or lactation) and regions (south, central or north). Plasma folate concentrations were measured by microbiological assay. The adjusted medians of folate concentration decreased from 28·8 (interquartile range (IQR) 19·9, 38·2) nmol/l in mid-pregnancy to 18·6 (IQR 13·2, 26·4) nmol/l in late pregnancy, and to 17·0 (IQR 12·3, 22·5) nmol/l in lactation (Pfor trend < 0·001). Overall, lower folate concentrations were more likely to be observed in women residing in the northern region, with younger age, higher pre-pregnancy BMI, lower education or multiparity, and in lactating women who had undergone a Caesarean delivery or who were breastfeeding exclusively. In total, 380 (31·4 %) women had a suboptimal folate status (folate concentration <13·5 nmol/l). Women in late pregnancy and lactating, residing in the northern region, having multiparity and low education level had a higher risk of suboptimal folate status, while those with older age had a lower risk. In conclusion, maternal plasma folate concentrations decreased as pregnancy progressed, and were influenced by geographic region and maternal socio-demographic characteristics. Future studies are warranted to assess the necessity of folic acid supplementation during later pregnancy and lactation especially for women at a higher risk of folate depletion.

Maternal age at first cesarean delivery related to adverse pregnancy outcomes in a second cesarean delivery: a multicenter, historical, cross-sectional cohort study.

BACKGROUND: To determine the effects of maternal age at first cesarean on maternal complications and adverse outcomes of pregnancy with the second cesarean. METHODS: This was a multicenter, historical, cross-sectional cohort study involving singleton pregnancies ≥28 gestational weeks, with a history of 1 cesarean delivery, and who underwent a second cesarean between January and December 2017 at 11 public tertiary hospitals in 7 provinces of China. We analyzed the effects of maternal age at first cesarean on adverse outcomes of pregnancy in the second cesarean using multivariate logistic regression analysis. RESULTS: The study consisted of 10,206 singleton pregnancies. Women were at first cesarean between 18 and 24, 25-29, 30-34, and ≥ 35 years of age; and numbered 2711, 5524, 1751, and 220 cases, respectively. Maternal age between 18 and 24 years at first cesarean increased the risk of placenta accreta spectrum (aOR, 1.499; 95% CI, 1.12-2.01), placenta previa (aOR, 1.349; 95% CI, 1.07-1.70), intrahepatic cholestasis of pregnancy (aOR, 1.947; 95% CI, 1.24-3.07), postpartum hemorrhage (aOR, 1.505; 95% CI, 1.05-2.16), and blood transfusion (aOR, 1.517; 95% CI, 1.21-1.91) in the second cesarean compared with the reference group (aged 25-29 years). In addition, maternal age ≥ 35 years at first cesarean was a risk factor for premature rupture of membranes (aOR, 1.556; 95% CI, 1.08-2.24), placental abruption (aOR, 6.464, 95% CI, 1.33-31.51), uterine rupture (aOR, 7.952; 95% CI, 1.43-44.10), puerperal infection (aOR, 6.864; 95% CI, 1.95-24.22), neonatal mild asphyxia (aOR, 4.339; 95% CI, 1.53-12.32), severe asphyxia (aOR, 18.439; 95% CI, 1.54-220.95), and admission to a neonatal intensive care unit (aOR, 2.825; 95% CI, 1.54-5.17) compared with the reference group (aged 25-29 years). CONCLUSIONS: Maternal age between 18 and 24 years or advanced maternal age at first cesarean was an independent risk factor for adverse maternal outcomes with the second cesarean. Advanced maternal age at the first cesarean specifically increased adverse neonatal outcomes with the second. Therefore, decisions as to whether to perform a first cesarean at a young or advanced maternal age must be critically evaluated.

Demographic variations and temporal trends in prenatal use of multiple micronutrient supplements in Beijing, 2013-2017.

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.

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 of gestational weight gain rate with infant anaemia in China: a birth cohort study.

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.

Prediction of iatrogenic preterm birth in patients with scarred uterus: a retrospective cohort study in Northeast China.

BACKGROUND: To build a novel and simple model to predict iatrogenic preterm birth in pregnant women with scarred uteri. METHODS: In this retrospective, observational, single-centre cohort study, data from 2315 patients with scarred uteri were collected. Multiple logistic regression analysis and mathematical modelling were used to develop a risk evaluation tool for iatrogenic preterm birth. After modelling, the calibration and discrimination of the model along with decision curve analysis were checked and performed to ensure clinical applicability. RESULTS: Among the 2315 patients, 417 (18.0%) had iatrogenic preterm births. The following variables were included in the model: interpregnancy interval (0 to < 12 months, OR 5.33 (95% Cl 1.79-15.91), P = 0.003; 13 to < 24 months (reference), 25 to < 60 months, OR 1.80 (95% CI 0.96-3.40), P = 0.068; ≥ 60 months, OR 1.60 (95% Cl 0.86-2.97), P = 0.14), height (OR 0.95, (95% CI 0.92-0.98), P = 0.003), parity (parity ≤1 (reference), parity = 2, OR 2.92 (95% CI 1.71-4.96), P < 0.0001; parity ≥3, OR 8.26, (95% CI 2.29-29.76), P = 0.001), number of vaginal bleeding (OR 1.81, (95% Cl 1.36-2.41), P < 0.0001), hypertension in pregnancy (OR 9.52 (95% CI 6.46-14.03), P < 0.0001), and placenta previa (OR 4.21, (95% CI 2.85-6.22), P < 0.0001). Finally, a nomogram was developed. CONCLUSIONS: In this study, we built a model to predict iatrogenic preterm birth for pregnant women with scarred uteri. The nomogram we created can assist doctors in evaluating the risk of iatrogenic preterm birth and help in making referrals; thus, better medical care can be given to improve the prognosis of patients and foetuses.

Development and Validation of Predictive Models for Vaginal Birth After Cesarean Delivery in China.

BACKGROUND The rate of delivery by cesarean section is rising in China, where vaginal birth after cesarean (VBAC) is in its early stages. There are no validated screening tools to predict VBAC success in China. The objective of this study was to identify the variables predicting the likelihood of successful VBAC to create a predictive model. MATERIAL AND METHODS This multicenter, retrospective study included 1013 women at ≥28 gestational weeks with a vertex singleton gestation and 1 prior low-transverse cesarean from January 2017 to December 2017 in 11 public tertiary hospitals within 7 provinces of China. Two multivariable logistic regression models were developed: (1) at a first-trimester visit and (2) at the pre-labor admission to hospital. The models were evaluated with the area under the receiver operating characteristic curve (AUC) and internally validated using k-fold cross-validation. The pre-labor model was calibrated and a graphic nomogram and clinical impact curve were created. RESULTS A total of 87.3% (884/1013) of women had successful VBAC, and 12.7% (129/1013) underwent unplanned cesarean delivery after a failed trial of labor. The AUC of the first-trimester model was 0.661 (95% confidence interval [CI]: 0.61-0.712), which increased to 0.758 (95% CI: 0.715-0.801) in the pre-labor model. The pre-labor model showed good internal validity, with AUC 0.743 (95% CI: 0.694-0.785), and was well calibrated. CONCLUSIONS VBAC provides women the chance to experience a vaginal delivery. Using a pre-labor model to predict successful VBAC is feasible and may help choose mode of birth and contribute to a reduction in cesarean delivery rate.

The Rates and Medical Necessity of Cesarean Delivery in the Era of the Two-Child Policy in Hubei and Gansu Provinces, China.

OBJECTIVES: To describe the cesarean rates in different child policy periods and assess the medical necessity of cesareans during the 2-child policy period. METHODS: We collected hospital-level aggregate data on 93 745 deliveries and individual-level data on 27 977 deliveries from 6 hospitals in the Hubei and Gansu provinces of China from 2013 to 2016. Experts in gynecology and obstetrics assessed the medical necessity of 1024 randomly selected cesareans in 2016. RESULTS: The overall cesarean rate decreased significantly from 45.1% in the 1-child policy period (January 2013-September 2014) to 40.4% in the selective 2-child policy period (October 2014-July 2016) and further to 38.9% in the universal 2-child policy period (August 2016-December 2016). The rate of cesarean delivery on maternal request decreased by 46.3%, whereas the rate of cesarean delivery indicated by a previous cesarean delivery increased by 118.8% (P < .001). The experts assessed 222 (21.6%) cesareans as lacking medical necessity. CONCLUSIONS: The overall cesarean rate in Hubei and Gansu provinces decreased after the implementation of the 2-child policy, and one fifth of cesareans might be nonessential.

Rate of gestational weight gain and adverse pregnancy outcomes in rural nulliparous women: a prospective cohort analysis from China.

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.

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.

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.

Under-5 mortality in 2851 Chinese counties, 1996-2012: a subnational assessment of achieving MDG 4 goals in China.

BACKGROUND: In the past two decades, the under-5 mortality rate in China has fallen substantially, but progress with regards to the Millennium Development Goal (MDG) 4 at the subnational level has not been quantified. We aimed to estimate under-5 mortality rates in mainland China for the years 1970 to 2012. METHODS: We estimated the under-5 mortality rate for 31 provinces in mainland China between 1970 and 2013 with data from censuses, surveys, surveillance sites, and disease surveillance points. We estimated under-5 mortality rates for 2851 counties in China from 1996 to 2012 with the reported child mortality numbers from the Annual Report System on Maternal and Child Health. We used a small area mortality estimation model, spatiotemporal smoothing, and Gaussian process regression to synthesise data and generate consistent provincial and county-level estimates. We compared progress at the county level with what was expected on the basis of income and educational attainment using an econometric model. We computed Gini coefficients to study the inequality of under-5 mortality rates across counties. FINDINGS: In 2012, the lowest provincial level under-5 mortality rate in China was about five per 1000 livebirths, lower than in Canada, New Zealand, and the USA. The highest provincial level under-5 mortality rate in China was higher than that of Bangladesh. 29 provinces achieved a decrease in under-5 mortality rates twice as fast as the MDG 4 target rate; only two provinces will not achieve MDG 4 by 2015. Although some counties in China have under-5 mortality rates similar to those in the most developed nations in 2012, some have similar rates to those recorded in Burkina Faso and Cameroon. Despite wide differences, the inter-county Gini coefficient has been decreasing. Improvement in maternal education and the economic boom have contributed to the fall in child mortality; more than 60% of the counties in China had rates of decline in under-5 mortality rates significantly faster than expected. Fast reduction in under-5 mortality rates have been recorded not only in the Han population, the dominant ethnic majority in China, but also in the minority populations. All top ten minority groups in terms of population sizes have experienced annual reductions in under-5 mortality rates faster than the MDG 4 target at 4.4%. INTERPRETATION: The reduction of under-5 mortality rates in China at the country, provincial, and county level is an extraordinary success story. Reductions of under-5 mortality rates faster than 8.8% (twice MDG 4 pace) are possible. Extremely rapid declines seem to be related to public policy in addition to socioeconomic progress. Lessons from successful counties should prove valuable for China to intensify efforts for those with unacceptably high under-5 mortality rates. FUNDING: National "Twelfth Five-Year" Plan for Science and Technology Support, National Health and Family Planning Commission of The People's Republic of China, Program for Changjiang Scholars and Innovative Research Team in University, the National Institute on Aging, and the Bill & Melinda Gates Foundation.

Geographic Variations and Temporal Trends in Cesarean Delivery Rates in China, 2008-2014.

Importance: The increasing use of cesarean delivery is an emerging global health issue. Prior estimates of China's cesarean rate have been based on surveys with limited geographic coverage. Objective: To provide updated information about cesarean rates and geographic variation in cesarean use in China. Design, Setting, and Data Sources: Descriptive study, covering every county (n = 2865) in mainland China's 31 provinces, using county-level aggregated information on the number of live births, cesarean deliveries, maternal deaths, and perinatal deaths, collected by the Office for National Maternal & Child Health Statistics of China, from 2008 through 2014. Exposures: Live births. Main Outcomes and Measures: Annual rate of cesarean deliveries. Results: Over the study period, there were 100 873 051 live births, of which 32 947 229 (32.7%) were by cesarean delivery. In 2008, there were 13 160 634 live births, of which 3 788 029 (28.8%) were by cesarean delivery and in 2014 there were 15 123 276 live births, of which 5 280 124 (34.9%) were by cesarean delivery. Rates varied markedly by province, from 4.0% to 62.5% in 2014. Despite the overall increase, by 2014 rates of cesarean delieries in 14 of the nation's 17 "super cities" had declined by 4.1 to 17.5 percentage points from their earlier peak values (median, 11.4; interquartile range, 6.3-15.4). In 4 super cities with the largest decreases, there was no increase in maternal or perinatal mortality. Conclusions and Relevance: Between 2008 and 2014, the overall annual rate of cesarean deliveries increased in China, reaching 34.9%. There was major geographic variation in rates and trends over time, with rates declining in some of the largest urban areas.