Changes in Maternal Socio-Demographic Characteristics and Pregnancy Outcomes Across Monitoring Regions - Six Provinces, China, 2016-2022.

What is already known about this topic?: In recent years, there has been a significant increase in the proportion of women of advanced maternal age (AMA), accompanied by a rise in adverse pregnancy outcomes in certain regions of China. What is added by this report?: From 2016 to 2022, there was an observed increase in the proportion of AMA, educational levels, and incidences of preterm birth and low birth weight (LBW) in both primiparous and multiparous women. Concurrently, there was a declining trend in the rate of cesarean deliveries and the incidence of macrosomia among multiparous women. What are the implications for public health practice?: In addition to focusing on health management for AMA individuals, proactive steps should be undertaken to enhance the quality of medical services and promote childbirth at optimal ages, thereby reducing the incidence of adverse pregnancy outcomes.

Effects of feeding patterns during the first 6 months on weight development of infants ages 0-12 months: a longitudinal study.

The purpose of this study was to investigate the effect of feeding patterns during the first 6 months on weight development of infants ages 0-12 months. Using monitoring data from the Maternal and Child Health Project conducted by the National Center for Women and Children's Health of the Chinese Center for Disease Control and Prevention from September 2015 to June 2019, we categorized feeding patterns during the first 6 months as exclusive breastfeeding, formula feeding, or mixed feeding. We calculated weight-for-age Z scores (WAZ) according to the World Health Organization's (WHO) 2006 Child Growth Standard using WHO Anthro version 3.2.2. A multilevel model was used to analyze the effect of feeding patterns during the first 6 months on the WAZ of infants ages 0-12 months in monitoring regions. Length of follow-up (age of infants) was assigned to level 1, and infants was assigned to level 2. Characteristics of infants, mothers, and families and region of the country were adjusted for in the model. The average weight of infants ages 0-12 months in our study (except the birth weights of boys who were formula fed or mixed fed) was greater than the WHO growth standard. After we adjusted for confounding factors, the multilevel model showed that the WAZ of exclusively breastfed and mixed-fed infants were statistically significantly higher than those of formula-fed infants (coefficients = 0.329 and 0.159, respectively; P < 0.05), and there was a negative interaction between feeding patterns and age (both coefficients = - 0.020; P < 0.05). Infants who were exclusively breastfed were heavier than formula-fed infants from birth until 12 months of age. Mixed-fed infants were heavier than formula-fed infants before 8 months, after which the latter overtook the former. Infants' weight development may be influenced by feeding patterns during the first 6 months. Exclusive breastfeeding during the first 6 months may be beneficial for weight development of infants in infancy.

Increased risk of preterm birth due to heat exposure during pregnancy: Exploring the mechanism of fetal physiology.

BACKGROUND: Heat exposure during pregnancy can increase the risk of preterm birth (PTB) through a range of potential mechanisms including pregnancy complications, hormone secretion and infections. However, current research mainly focuses on the effect of heat exposure on pathophysiological pathways of pregnant women, but ignore that maternal heat exposure can also cause physiological changes to the fetus, which will affect the risk of PTB. OBJECTIVE: In this study, we aimed to explore the mediating role of fetal heart rate (FHR) in the relationship between maternal heat exposure and PTB incidence. METHODS: We assigned heat exposure to a multi-center birth cohort in China during 2015-2018, which included all 162,407 singleton live births with several times FHR measurements during the second and third trimesters. We examined the associations between heat exposure, FHR and PTB in the entire pregnancy, each trimester and the last gestational month. The inverse odds ratio-weighted approach applied to the Cox regression was used to identify the mediation effect of heat exposure on PTB and its clinical subtypes via FHR. FINDINGS: Exposure to heat significantly increased the risk of PTB during the third trimester and the entire pregnancy, hazard ratios and 95 % CIs were 1.266 (1.161, 1.379) and 1.328 (1.218, 1.447). Heat exposure during the third trimester and entire pregnancy increased FHR in the third trimester by 0.24 bpm and 0.14 bpm. The proportion of heat exposure mediated by FHR elevation on PTB and its subtype ranged from 3.68 % to 24.06 %, with the significant mediation effect found for both medically indicated PTB and spontaneous PTB. CONCLUSIONS: This study suggests that heat exposure during pregnancy has an important impact on fetal health, and FHR, as a surrogate marker of fetal physiology, may mediate the increased risk of PTB caused by extreme heat. Monitoring and managing physiological changes in the fetus would constitute a promising avenue to reduce adverse birth outcomes associated with maternal heat exposure.

Prevalence and influencing factors of anemia among pregnant women across first, second and third trimesters of pregnancy in monitoring areas, from 2016 to 2020: a population-based multi-center cohort study.

OBJECTIVE: To assess the prevalence of anemia among pregnant women across their entire pregnancy and the factors affecting it in the monitoring areas. METHODS: A total of 108,351 pregnant women who received antenatal health care and delivered from January 1, 2016 to December 31, 2020 in 15 monitoring counties of 8 provinces in the Maternal and Newborn Health Monitoring Program (MNHMP) of National Center for Women and Children's Health (NCWCH) were selected as the study subjects. The anemia status among the subjects across their first, second and third trimester of pregnancy and the influencing factors were analyzed. RESULTS: From 2016 to 2020, the prevalence of anemia at any stage during pregnancy in the monitoring areas was 43.59%. The prevalence of anemia among pregnant women across all three trimesters was 3.95%, and the prevalence of mild and moderate-to-severe anemia was 1.04% and 2.90%, respectively. Protective factors were living in the northern area (OR = 0.395) and being a member of an ethnic minority (OR = 0.632). The risk factors were residing in rural areas (OR = 1.207), with no more than junior high school education (OR = 1.203), having ≥ 3 gravidities (OR = 1.195) and multiple fetuses (OR = 1.478). CONCLUSIONS: Although the prevalence of anemia among pregnant women across all trimesters in the monitoring area was low, the severity of anemia was high. Since the prevalence of anemia among pregnant women across their entire pregnancy in the monitoring area is affected by many different factors, more attention should be paid to pregnant women living in rural areas, with low literacy, ≥ 3 gravidities and multiple fetuses for early intervention.