Ye Rw

Low first-trimester hemoglobin and low birth weight, preterm birth and small for gestational age newborns

Objective: To examine the relationship between first‐trimester hemoglobin (Hb) concentration and risk of low birth weight (LBW), preterm birth and small for gestational age (SGA). Methods: Data were obtained from a population‐based prenatal care program in China. A total of 88,149 women who delivered during 1995–2000 and had their Hb measured in the first trimester were selected as study subjects. Results: The prevalence of anemia (Hb < 110 g/L) was 22.1% in the first trimester. The risk of LBW, preterm birth and SGA was increased steadily with the decrease of first‐trimester Hb concentration. After controlling for confounding factors, women with Hb 80–99 g/L had significantly higher risk for LBW (OR = 1.44, 95% CI 1.17–1.78), preterm birth (OR = 1.34, 95% CI 1.16–1.55) and SGA (OR = 1.13, 95% CI 0.98–1.31) than women with Hb 100–119 g/L. No elevated risk was noted for women with Hb ≥ 120 g/L. Conclusion: Low first‐trimester Hb concentration increases the risk of LBW, preterm birth and SGA.

Placental concentrations of mercury, lead, cadmium, and arsenic and the risk of neural tube defects in a Chinese population.

To examine whether in utero exposure to mercury (Hg), cadmium (Cd), lead (Pb) and arsenic (As) is associated with an elevated neural tube defects (NTDs) risk, placental concentrations of total Hg, Cd, Pb and As were measured with an inductively coupled plasma mass spectrometer (ICP-MS) in 36 anencephaly and 44 spina bifida cases as well as in 50 healthy controls. The median Hg concentration in the NTD cases (2.25 ng/g) was higher than that of the controls (1.16 ng/g). The odds ratio (OR) for an Hg concentration above the median was 8.80 (95% CI 3.80-20.36) for the NTD cases. NTD risks increased for the second and third high levels of the concentrations, with ORs of 2.70 (95% CI 1.13-6.43) and 18.20 (95% CI 5.45-60.73), respectively. Therefore, higher placental levels of Hg are associated with an elevated risk of NTDs.

Caesarean delivery, caesarean delivery on maternal request and childhood overweight: a Chinese birth cohort study of 181 380 children.

What is already known about this subject Both rates of caesarean section and childhood overweight have been steadily increasing over the past decade in many parts of the world. Caesarean delivery on maternal request contributes remarkably to the rising trend of caesarean births. A few small‐scale studies suggest that caesarean section may be associated with later overweight and obesity, whereas little is known about the impact of caesarean delivery on maternal request.

Caesarean delivery on maternal request and childhood psychopathology: a retrospective cohort study in China

Please cite this paper as: Li H‐T, Ye R, Achenbach T, Ren A, Pei L, Zheng X, Liu J‐M. Caesarean delivery on maternal request and childhood psychopathology: a retrospective cohort study in China. BJOG 2011;118:42–48.

Association of preconceptional health care utilization and early initiation of prenatal care.

Objective:To assess whether women having preconceptional health care utilization were more likely to have early initiation of prenatal care than were women not having preconceptional health care utilization.Study Design:In this cohort study, data were collected prospectively from a population-based Perinatal Health Care Surveillance System in China. The analysis included 195 796 women who delivered single live births in 13 cities/counties during 1997 to 2000. Mantel–Haenszel test was employed to calculate risk ratios and 95% confidence intervals (CI). Multivariate logistic regression was conducted to assess the association between preconceptional health care utilization and early initiation of prenatal care after controlling for maternal residence, age at delivery, educational attainment, occupation, parity, preconceptional medical disorders, and high-risk medical experiences during the first trimester. SPSS 11.5 (SPSS Inc.) was employed for data analysis.Results:Women having preconceptional health care utilization were 2.6 times (95%CI: 2.5 to 2.6) more likely to have early initiation of prenatal care compared with women not having preconceptional health care utilization. When stratified by maternal residence, age at delivery, educational attainment, occupation, parity, preconceptional medical disorder, high-risk medical experiences during the first trimester, and preconceptional medical disorders, this association still existed. After controlling for stratification factors mentioned above and the interaction of maternal age, educational attainment, and parity, women having preconceptional health care utilization were 2.7 times (95%CI: 2.6 to 2.8) more likely to have early initiation of prenatal care than were women not having preconceptional health care utilization.Conclusion:Women who had preconceptional health care utilization were more likely to have early prenatal care than were women not having preconceptional health care utilization.

Exposure of methyl mercury in utero and the risk of neural tube defects in a Chinese population.

To determine if exposure to methyl mercury (MeHg) in utero is associated with an elevated risk of neural tube defects (NTDs), we measured its concentration in the placentas of 36 anencephalic and 44 spina bifida cases, as well as in 50 healthy controls. The median MeHg concentration in NTD cases (0.49ng/g) was higher than that in controls (0.33ng/g). The crude and adjusted odds ratios (ORs) for a MeHg concentration above the median were 3.54 (95% confidence interval (CI), 1.68-7.49) and 3.64 (95% CI, 1.66-7.99), respectively. Both anencephaly and spina bifida subtypes had higher levels of MeHg than the controls. NTD risk increased for subjects in the second and third highest tertile of MeHg concentrations, with an OR of 2.24 (95% CI, 0.93-5.40) and 2.85 (95% CI, 1.17-6.94), respectively. In summary, higher placental levels of MeHg are associated with an elevated risk of NTDs.

Low 3rd trimester haemoglobin level and the risk of post-term pregnancy

The aim of this study was to examine the association between haemoglobin (Hb) concentration during pregnancy and the risk of post-term pregnancy (PTP). Based on data from a population-based prenatal care programme in South China, a total of 102,484 women who delivered during 1995–2000 were identified. Haemoglobin concentration was determined by using standard methods. Risk of PTP was analysed according to severity of anaemia and multiple Hb categories. Multivariable logistic regression models were used to control potential confounding factors. Results showed that the overall prevalence rate of PTP in the population was 4.8% (4,947/102,484). The rate was 5.0%, 4.7% and 4.8% for women who were anaemic, while it was 4.5%, 4.4% and 4.2% for women who were non-anaemic in the 1st, 2nd and 3rd trimester, respectively. Although anaemia in either of the trimesters was not significantly associated with an increased risk of PTP, the risk was two-fold higher (odds ratio, 2.06; 95% CI, 1.18–3.59) for women whose last trimester haemoglobin concentration was lower than 80 g/l, when compared with women whose last trimester haemoglobin concentration was 140 g/l or higher. Our findings suggest that a very low 3rd trimester haemoglobin level is associated with an increased risk of PTP.

Establishment and Evaluation of Enzyme-linked Immunosorbent Assay for Measuring Human IgM Autoantibody to Folate Receptor

OBJECTIVE To establish the method of enzyme-linked immunosorbent assay (ELISA) for measuring human IgM autoantibody to folate receptor. METHODS Folate receptor was extracted and purified from the healthy woman placenta. The protein was coated on 96-well plates with a concentration of 5 ng/Μl. Goat monoclonal antibody was used for detecting antibody. Pooled plasma from healthy donors was used to plot the standard curve and the IgM concentration of pooled plasma was defined as 1. We set up an ELISA procedure to measure human IgM autoantibody to folate receptor. The sensitivity, precision, and stability of the method were evaluated. Further, the folate receptor and bovine folate-binding protein were used as the antigen, respectively, to determine the autoantibody levels in 24 healthy individuals and 20 individuals once gave birth to baby with neural tube defects. RESULTS The measuring range of the method was from 6.25 × 10⁻⁴ to 8.00 × 10⁻². The lowest IgM level that can be detected was 3.12 × 10⁻⁴. The inter-assay coefficients of variations for samples with high, medium, and low IgM levels were 6.61%,3.50%, and 5.12%, respectively. The intra-assay coefficients of variations were 4.54%, 5.49%, and 5.44%, respectively. The stability test results were considered within acceptable limits. The data from folate receptor-ELISA was significantly higher than that from bovine folate binding protein-ELISA, both in the healthy group (t=-11.9, P<0.001) and in the neural tube defect group (t = 7.35, P<0.001). CONCLUSIONS The folate receptor-ELISA method for measuring human IgM autoantibody to folate receptor was successfully established. The method is sensitive, repeatable, and stable.