Structural transition of parenthood among Chinese nulliparous couples with planned pregnancies, 2013-2019.

BACKGROUND: The postponement of parenthood is a global public health issue that has received attention of many public health experts. However, few studies have investigated the postponement in marriage age, marriage and conception interval, and pregnancy age in terms of demographic and regional heterogenicities. METHODS: This is a cross-sectional, registry-based study, and a total of 13 894 601 nulliparous couples who participated in the National Free Pre-Pregnancy Check-ups Project and became pregnant during 2013-2019 were included. We calculated annual percentage change and forest plots for marriage age, marriage and conception interval, and pregnancy age. RESULTS: Late marriage (marriage age ≥ 35 years), long marriage and conception interval (marriage and conception interval ≥ 2 years), and advanced pregnancy (pregnancy age ≥ 35 years) increased from 1.20%, 22.01%, and 1.88% in 2013 to 1.69%, 32.75%, and 2.79% in 2019, respectively. The corresponding annual percentage changes were 6.55%, 8.44%, and 8.17%. Participants without higher education had a higher annual percentage change, but comparable prevalence for long marriage and conception interval with participants with higher education. Participants residing in second- or new first-tier cities, and the northeast of China who had a higher prevalence of parenthood postponement also had higher corresponding annual percentage changes. CONCLUSIONS: Structural postponement of parenthood with demographic and regional heterogenicities was observed among Chinese nulliparous couples with planned pregnancies during 2013-2019. Inclusive and comprehensive parenting support should be developed and implemented in mainland China to minimize the negative health effects arising from the postponement, especially for couples without higher education and living in new first/second-tier cities or the northeast China.

Burden and Trend of Macrosomia and Large-for-Gestational-Age Neonates Attributable to High Pre-Pregnancy Body Mass Index in China, 2013-2017: A Population-Based Retrospective Cohort Study.

Background: The world is transitioning to an obese future, but few studies have measured the burden of increased maternal body mass index (BMI) on pathological fetal overgrowth, especially the trends in this burden and its heterogeneity in populations with different characteristics. Methods: A population-based retrospective cohort study was conducted with 7,998,620 Chinese females who had participated in the National Free Pre-Pregnancy Check-ups Project and became pregnant during 2013-2017. The proportions of macrosomic and LGA neonates attributable to high BMI (population attributable fraction, PAF) and annual percent change of yearly PAFs were estimated. Results: We found that the burden of macrosomic and LGA (large-for-gestational-age) neonates attributable to high pre-pregnancy BMI increased among Chinese females with planned pregnancies during 2013-2017. The PAF of macrosomia attributable to high BMI increased from 3.16% (95% confidence interval: 2.97-3.35%) to 7.11% (6.79-7.42%) by 23.60% (16.76-30.85%) annually, and the PAF of LGA increased from 2.35% (2.21-2.48%) to 5.00% (4.79-5.21%) by 21.98% (16.14-28.11%) annually. Our study identified that participants with disadvantaged socioeconomic status (including those without higher education, living in provinces with GDP per capita < 40,000 CNY, tier IV, and tier V cities) and residing in northern and southwestern China were at high risk of a rapidly expanding burden. Conclusions: Government authorities should control pre-pregnancy BMI through nationwide intervention programs and direct more resources to focus on the unfair burden on females with disadvantaged socioeconomic status.