Ersheng Gao

Effects of caesarean section on maternal health in low risk nulliparous women: a prospective matched cohort study in Shanghai, China

BackgroundRates of caesarean section are progressively increasing in many parts of the world. As a result of psychosocial factors there has been an increasing tendency for pregnant women without justifiable medical indications for caesarean section to ask for this procedure in China. A critical examination of this issue in relation to maternal outcomes is important. At present there are no clinical trials to help assess the risks and benefits of caesarean section in low risk women. To fill the gap left by trials, this indication-matched cohort study was carried out to examine prospectively the outcomes of caesarean section on women with no absolute obstetric indication compared with similar women who had vaginal delivery.MethodsAn indication-matched cohort study was undertaken to compare maternal outcomes following caesarean section with those undergoing vaginal delivery, in which the two groups were matched for non-absolute indications. 301 nulliparous women with caesarean section were matched successfully with 301 women who delivered vaginally in the Maternal and Childrens Hospitals (MCHs) in Shanghai, China. Logistic regression model or binomial regression model was used to estimate the relative risk (RR) directly. Adjusted RRs were calculated adjusting for propensity score and medical indications.ResultsThe incidence of total complications was 2.2 times higher in the caesarean section group during hospitalization post-partum, compared with the vaginal delivery group (RR = 2.2; 95% CI: 1.1-4.4). The risk of haemorrhage from the start of labour until 2 hours post-partum was significantly higher in the caesarean group (RR = 5.6; 95% CI: 1.2-26.9). The risk of chronic abdominal pain was significantly higher for the caesarean section group (RR = 3.6; 95% CI: 1.2-10.9) than for the vaginal delivery group within 12 months post-partum. The two groups had similar incidences of anaemia and complicating infections such as wound complications or urinary tract infection.ConclusionsIn nulliparous women who were at low risk, caesarean section was associated with a higher rate of post-partum morbidity. Those requesting the surgical procedure with no conventional medical indication, should be advised of the potential risks.

Exposure to bisphenol-A and reproductive hormones among male adults

BACKGROUND Bisphenol A (BPA) is a suspected human endocrine disruptor which is widely used. METHODS In order to determine whether urine BPA level is associated with serum reproductive hormone levels among male adults, we carried out a cross-sectional study in China. We recruited 592 male workers and collected their urine samples for BPA measurement. We also collected blood samples and examined serum reproductive hormones. We used multiple linear regression and log-binomial model to examine associations between urine BPA level and hormone levels after controlling for age and smoking status. RESULTS An increased urine BPA level was associated with increased prolactin (p<0.001), estradiol (p<0.001), sex hormone-binding globulin level (p=0.001), and a reduced androstenedione (p<0.001) and free androgen index level (p=0.021). Males, whose urine BPA level was in the 2nd, 3rd and highest quartiles, had respectively 1.58, 1.33 and 3.09-fold increased prevalence of having a high prolactin level (>P75 level). The highest quartile of BPA level was associated with 1.63 and 1.50-fold increased prevalence of having a high estradiol and elevated sex hormone-binding globulin level. Males with higher quartile of BPA level had a lower inhibin B level. CONCLUSION High BPA exposure is associated with increased prolactin, estradiol and sex hormone-binding globulin level in males, and may contribute to male infertility.

Mifepristone-induced abortion and placental complications in subsequent pregnancy

BACKGROUND The aim of the study was to explore the effect of first-trimester mifepristone-induced abortion (MA) on placental complications in subsequent pregnancy. METHODS Two cohorts of nulliparous pregnant women were recruited in China during early pregnancy, one with a history of one MA and the other with no abortion (NA). Women were followed up until delivery. RESULTS The incidence proportions of abruptio placenta, placenta previa, placenta accreta and retained placenta in the MA group (4673) and NA group (4690) were, respectively, 0.5 and 0.3, 0.8 and 0.9, 0.5 and 0.5, and 0.7 and 0.8% (all differences non-significant). After adjustment for center, age, education, occupation, residence, income, BMI and type of delivery, the incidence rates of placenta previa, accreta and retained placenta in the MA and NA groups showed no significant differences. The risk of abruptio placenta in women with a MA was nearly double that of women with no abortion, although this apparent increased risk was not statistically significant. Furthermore, this increased risk of abruptio placenta was found only in those with a gestational age >6 weeks at abortion (aOR: 2.46; 95% CI: 1.00-6.04), a curettage after abortion (aOR: 3.00; 95% CI: 1.25-7.20) or a longer inter-pregnancy interval (P-value for trend: 0.022). CONCLUSIONS Mifepristone-induced abortion itself is not associated with placental complications in subsequent pregnancy, but other factors related to medical abortion-such as a gestational age >6 weeks at abortion, a curettage after abortion, and a longer interpregnancy interval-may increase the risk of abruptio placenta.

Associations between Bisphenol A Exposure and Reproductive Hormones among Female Workers.

The associations between Bisphenol-A (BPA) exposure and reproductive hormone levels among women are unclear. A cross-sectional study was conducted among female workers from BPA-exposed and unexposed factories in China. Women’s blood samples were collected for assay of follicle-stimulating hormone (FSH), luteinizing hormone (LH), 17β-Estradiol (E2), prolactin (PRL), and progesterone (PROG). Their urine samples were collected for BPA measurement. In the exposed group, time weighted average exposure to BPA for an 8-h shift (TWA8), a measure incorporating historic exposure level, was generated based on personal air sampling. Multiple linear regression analyses were used to examine linear associations between urine BPA concentration and reproductive hormones after controlling for potential confounders. A total of 106 exposed and 250 unexposed female workers were included in this study. A significant positive association between increased urine BPA concentration and higher PRL and PROG levels were observed. Similar associations were observed after the analysis was carried out separately among the exposed and unexposed workers. In addition, a positive association between urine BPA and E2 was observed among exposed workers with borderline significance, while a statistically significant inverse association between urine BPA and FSH was observed among unexposed group. The results suggest that BPA exposure may lead to alterations in female reproductive hormone levels.

Dimensions of the endometrial cavity and intrauterine device expulsion or removal for displacement: a nested case–control study

To evaluate the effect of the dimensions of the uterine cavity in relation to the expulsion, or removal for displacement, of intrauterine devices (IUDs) MLCu375 and TCu380A.

Mifepristone-induced abortion and vaginal bleeding in subsequent pregnancy

BACKGROUND The aim of this study is to explore the effect of first-trimester mifepristone-induced abortion on vaginal bleeding in subsequent pregnancy. STUDY DESIGN This observational cohort study was conducted during 1998-2001 at antenatal clinics in Beijing, Chengdu, and Shanghai, China. The study enrolled 4,931 women with one previous mifepristone-induced abortion, 4,925 women with no history of induced abortion, and 4,800 women with one previous surgical abortion and followed them through pregnancy and childbirth. RESULTS The rates of vaginal bleeding in pregnant women with a history of medical abortion, no abortion, and surgical abortion were 16.5%, 13.9%, and 17.3%, respectively. The women with medical abortion had a higher risk (adjusted relative risk (aRR)=1.17, 95% confidence interval (CI): 1.07, 1.29) of vaginal bleeding compared with those with no abortion but similar risk to prior surgical abortion. When the correlation between medical abortion and vaginal bleeding was examined by period, increased risk was observed only in the early period (<16 gestational weeks) (aRR=1.25, 95% CI: 1.12, 1.39). The comparison between subgroups of medical abortion and no abortion showed that the observed risks increased particularly in those with abortion at gestational age ≤ 7 weeks (aRR=1.33, 95% CI: 1.18, 1.49), those followed by a postabortion curettage (aRR=1.58, 95% CI: 1.37, 1.84) or complications (aRR=1.99, 95% CI: 1.67, 2.37). There was no difference between women with medical abortion and women with surgical abortion in the occurrence of vaginal bleeding for either period. CONCLUSIONS One previous mifepristone-induced abortion increased the risk of vaginal bleeding in early gestation period of subsequent pregnancy compared with no abortion, especially if abortion occurred before 7 weeks of gestation and was followed by a curettage or complications.

The relationship between age at menarche and infertility among Chinese rural women

OBJECTIVE To explore the relationship between age at menarche and infertility. STUDY DESIGN The cross-sectional study investigated 6906 couples from the communities in Sandu Shui Autonomous County of Guizhou Province, China. Face to face interviews were conducted to collect information on age at menarche and time to first pregnancy, as well as demographic characteristics and lifestyle factors. Infertility was defined as being unable to become pregnant after attempting for ≥12 months. Poisson regression was used to assess the relationship between age at menarche and infertility of first attempt. RESULTS The prevalence rate of infertility for the first pregnancy attempt of the study population was 11.87%. There is an obvious monotonic, almost linear, trend of prevalence rate of infertility with increasing age at menarche (P for trend: <0.001). Compared with wives with age at menarche of 13 years, the prevalence ratios of infertility were 0.71 (95%CI: 0.42, 1.20), 1.33 (95%CI: 1.05, 1.68), 1.47 (95%CI: 1.17, 1.85), 1.57 (95%CI: 1.20, 2.04), 1.41 (95%CI: 1.00, 1.99) and 1.73 (95%CI: 1.18, 2.52) for wives with age at menarche of ≤12, 14, 15, 16, 17 and ≥18 years, respectively, after adjusting for wifes year at birth, age at marriage, ethnic group, education and occupation, and husbands smoking and drinking habits before marriage. CONCLUSIONS The present community-based study indicated that increasing age at menarche was associated with an increased risk of infertility in the study population.

Mifepristone-induced abortion and duration of third stage labour in a subsequent pregnancy

To evaluate the impact of mifepristone-induced abortion (MA) on the duration of third stage labour in a subsequent pregnancy, an observational cohort study was conducted from 1998 to 2001 at antenatal clinics in Shanghai, Beijing and Chengdu, China. A total of 4925 pregnant women with no history of induced abortion (NA) and 4931 pregnant women with one previous MA were enrolled and followed until delivery. Of these, 5139 women who delivered singletons vaginally were used in the present analyses, including 2614 with NA and 2525 with a history of MA. Maternal characteristics, labour duration and other obstetric and gynaecological information were obtained. The incidence rates of prolonged third stage of labour were 1.55% and 1.49% in NA and MA, respectively. After adjusting for age at delivery, maternal education, maternal occupation, area of residence, duration of gestational, type of delivery and pregnancy-induced hypertension, MA was not associated with the risk of prolonged third stage of labour (odds ratios = 0.92, 95% confidence interval 0.58, 1.44). Subgroup analysis of women with MA showed similar results regardless of gestational age at abortion, womans age at abortion, subsequent curettage/complications and the interpregnancy interval. In conclusion, the data did not provide evidence that one MA was associated with the risk of prolonged third stage of labour in a subsequent pregnancy in primiparae.

Effect of interpregnancy interval after a mifepristone-induced abortion on neonatal outcomes in subsequent pregnancy

BACKGROUND The study evaluated effects of interpregnancy interval (IPI) on neonatal outcomes after mifepristone-induced abortion in the first pregnancy. STUDY DESIGN This observational cohort study, conducted from 1998 to 2001 at antenatal clinics in Shanghai, Beijing, and Chengdu, China, included 4682 nulliparous women with one mifepristone-induced abortion in their first pregnancy, who were enrolled and followed up until delivery. We compared neonatal outcomes among women with different IPIs between their mifepristone-induced abortion and subsequent pregnancy. RESULTS When compared to IPI of 18-24 months, there was an increased risk of the neonate being small for gestational age (SGA) [adjusted odds ratio (aOR): 2.01; 95% confidence interval (CI): 1.04-3.88] when IPI was <6 months; this risk was greater among women without a curettage history after abortion (aOR: 2.49; 95% CI: 1.13-5.50). The associations between IPI and preterm delivery (<37 weeks), low birth weight (<2500 g), mean birth weight and ponderal index were not statistically significant. CONCLUSIONS The results indicate that an IPI <6 months after one mifepristone-induced abortion in first pregnancy is associated with an increased risk of SGA in the subsequent pregnancy.

Effects of Cesarean Section on Infant Health in China: Matched Prospective Cohort Study

Objective To compare the medical outcomes of infants delivered by cesarean section with those of infants delivered vaginally. Methods A total of 301 healthy women with cesarean section and a matched control group of 301 women delivered vaginally were identified at three district-level hospitals in Shanghai from May 2001 to February 2003. Two groups were matched according to their medical indications for cesarean section. Their infants were assessed at delivery, 1 month, 6 month and 1 year after birth. Results The incidence of neonatal complications and infant morbidities at all measurement occasions did not differ significantly between groups. Rehospitalization was found to be more likely among infants delivered by cesarean section in the first month after birth. However, there was no difference between two groups in the incidence of rehospitalization in the first year after birth. Cesarean section was also associated with a higher risk of infant diarrhea (adjusted relative risk=1.25, 95% CI: 1.01, 1.56). Conclusion Infants did not have health benefits from cesarean section if the pregnancy was at low risk.