Xiaohong Liu

Heavy metals (lead [Pb], cadmium [Cd], arsenic [As], mercury [Hg], manganese [Mn], copper [Cu], zinc [Zn], and iron [Fe]) might be risk factors for pre-eclampsia (PE), whereas their joint effect remains unclear. To address this issue, we conducted a nested case–control study consisting of 49 PE cases and 329 controls from a Chinese prospective birth cohort and divided the participants into low/high and quartile groups based on hair metal concentrations. We used logistic regression models and a weighted quantile sum (WQS) model to investigate the independent and mixed associations between these eight heavy metals in maternal hair and the risk of PE. After multivariable adjustment, high hair Pb was associated with a 2.53-fold increased risk of PE, and significantly higher risks of PE were also observed in quartiles 2 to 4 of Pb and quartiles 3 to 4 of Fe. The WQS model revealed a statistically significant association between maternal co-exposure to all eight heavy metals and the risk of PE, with Pb, As, and Fe presenting the biggest risk. Therefore, high maternal exposure to heavy metals may increase the risk of PE. It is crucial to consider co-exposure to multiple heavy metals throughout pregnancy in future research endeavors.

To evaluate the efficacy of Multiple Micronutrient (MMN) Supplements during pregnancy in reducing the risk of anemia among pregnant women. A retrospective cohort study was conducted with the supplement of Folic Acid (FA) only and FA plus MMN groups. Data was collected through questionnaires during the first prenatal visit. Hemoglobin levels were extracted from the Laboratory Information System. A total of 4,239 pregnant women who were admitted to Beijing Haidian Maternal & Child Health Hospital between May 2017 and November 2020 was evaluated. Chi-square tests and log-binomial regression were conducted to evaluate the relative risks (RRs) of two groups on the reduction of anemia during pregnancy. The supplement of MMN was found to significantly decrease the risk of anemia in the later stages of pregnancy. Focusing on the third trimester specifically, the crude RR and adjusted RR were 0.891 and 0.844 respectively. In the second and third trimester of pregnancy, a sufficient monthly intake frequency of MMN(≥ 24 pills) is associated with a lower relative risk of anemia, with a value of 0.897 and 0.809 compared to the group supplement FA only. The supplement of MMN has been correlated with a reduced risk of anemia in the second and third trimesters of pregnancy. But the efficacy was limited in the first trimester. Frequent and early initiation of supplementation with FA and MMN pills is associated with a more significant reduction in the risk of anemia compare to group supplement of FA only.

What is already known about this topic? Inconsistent results have been reported on the association between periconceptional folic acid only (FAO) or multiple micronutrients containing folic acid (MMFA) supplementation and the risk of gestational diabetes mellitus (GDM) in previous research. What is added by this report? In a prospective cohort study conducted among pregnant women in Haidian District, Beijing Municipality, it was observed that those who took MMFA demonstrated a higher likelihood of developing GDM in comparison to those who consumed FAO periconceptionally. Interestingly, the increased risk for GDM in pregnant women supplemented with MMFA compared to FAO was primarily due to changes in fasting plasma glucose. What are the implications for public health practice? It is highly recommended that women prioritize the use of FAO in order to yield potential benefits in the prevention of GDM.

What is already known about this topic? Interpregnancy intervals (IPIs) that are either excessively long or short have been linked with an elevated risk of adverse perinatal outcomes. Presently, no pertinent guidelines have been established in China to provide clear direction with regard to optimal IPI. What is added by this report? A brief interpregnancy interval may elevate the risk of miscarriage, postpartum hemorrhage, and fetal distress among expectant women. What are the implications for public health practice? These results could inform prenatal consultations, guiding pregnant women towards an ideal interpregnancy interval of no less than 24 months.

Background: Increasing evidence has shown that active smoking can increase the risk of gestational diabetes mellitus (GDM), but the effect of passive smoking is still unknown. Women in pregnancy are vulnerable to secondhand smoke. This study explored the association of passive smoking with GDM in China. Method: A total of 3083 nonsmoking pregnant women living in Beijing were recruited into a prospective cohort study. Sociodemographic and passive smoking data were collected with structured questionnaires during face-to-face interviews. Glucose levels were measured by physicians according to standard protocols. Multivariate logistic regression was performed for the association estimation after accounting for potential confounders. Result: In total, 562 of the 3083 participants developed GDM (18.23%); 779 participants (25.27%) reported exposure to passive smoking. After adjusting for age, BMI, ethnicity, education, occupation, and parity, passive smoking conferred an approximately 1.4-fold risk increase in GDM (adjusted odds ratio (OR) = 1.37, 95% confidence interval (CI): (1.11, 1.70)). The adjusted ORs with 95% CIs for passive smoking levels of <1, 1–6, and ≥7 times per week were 1.21 (0.94, 1.55), 1.81 (1.22, 2.69), and 1.70 (1.02, 2.84), respectively. An obvious passive-smoking–GDM association was observed among only nulliparous women (adjusted OR = 1.45, 95% CI: (1.14, 1.85)). Conclusion: Frequent exposure to secondhand smoke could increase the risk of GDM among nonsmoking pregnant women. Parity status might modify their association. Public policies should be advocated to prevent passive smoking among this population.

What is already known on this topic? Neural tube defects can be effectively prevented by folic acid supplementation. However, compliance with the recommendations for supplementation is still low in China. What is added by this report? This study investigated the rate of correct use of folic acid supplementation and its risk factors among pregnant women in Beijing. Women who took folic acid correctly only comprised less than 50% of the total, possibly due to unexpected pregnancy. What are the implications for public health practice? Given the low rate in Beijing, an area with high health literacy, the rate may also be low in other areas in China. Regulations for mandatory fortification of food with folic acid are recommended in China.

What is already known about this topic? The coronavirus disease 2019 (COVID-19) pandemic potentially affected prenatal care quality and maternal and fetal outcomes globally. What is added by this report? During COVID-19 pandemic period, the rates of caesarean sections (CS) and preterm birth for uninfected pregnant women increased slightly in areas that were relatively severely impacted by the pandemic in China. The overall number of prenatal examinations did not dramatically decrease, while the eligible examinations significantly decreased in Hubei Province. What are the implications for public health practice? Routine prenatal examinations had been well maintained during the pandemic period in China. In the future, in-time prenatal examinations should be provided to improve the quality of screening and management of high-risk pregnancy under pandemic-affected circumstances. Psychological counseling and transfer treatment channels should be strengthened for pregnant women during lockdown period.

Objective: To assess the relationship between preconception body mass index (BMI) and cervical length (CL). Methods: Data was collected from a prospective cohort study conducted in Beijing, China. A total of 4843 qualified women participated in this study, whose health-related information was recorded at the very beginning and their cervical length was measured with transvaginal ultrasound examination during 22–24 gestational weeks. Logistic regression was used to evaluate the relationship between preconception BMI and cervical length, after adjusting for potential confounders. Results: Of all the participants in the analysis, 580 (12.0%) women had a short cervical length (CL less than 30 mm). After adjusting for the age and parity status, the adjusted odds ratios of short CL for underweight: adjusted OR = 1.28 (95% CI: 1.02, 1.60); overweight: adjusted OR = 0.74 (95% CI: 0.55, 0.99); obesity: adjusted OR = 0.38 (95% CI: 0.17, 0.88) compared with normal weight. The mean CL in underweight, normal weight, overweight and obesity group demonstrated a significant linear increased trend (33.47, 34.16 and 34.96 mm, respectively) (p < .05), dependent of age and parity. Conclusions: This research revealed that low preconception BMI women were more likely to have a short CL.