Association of interpregnancy interval and risk of adverse pregnancy outcomes in woman by different previous gestational ages / 中华医学杂志(英文版)

BACKGROUND@#With an increasing proportion of multiparas, proper interpregnancy intervals (IPIs) are urgently needed. However, the association between IPIs and adverse perinatal outcomes has always been debated. This study aimed to explore the association between IPIs and adverse outcomes in different fertility policy periods and for different previous gestational ages.@*METHODS@#We used individual data from China's National Maternal Near Miss Surveillance System between 2014 and 2019. Multivariable Poisson models with restricted cubic splines were used. Each adverse outcome was analyzed separately in the overall model and stratified models. The stratified models included different categories of fertility policy periods (2014-2015, 2016-2017, and 2018-2019) and infant gestational age in previous pregnancy (<28 weeks, 28-36 weeks, and ≥37 weeks).@*RESULTS@#There were 781,731 pregnancies enrolled in this study. A short IPI (≤6 months) was associated with an increased risk of preterm birth (OR [95% CI]: 1.63 [1.55, 1.71] for vaginal delivery [VD] and 1.10 [1.03, 1.19] for cesarean section [CS]), low Apgar scores and small for gestational age (SGA), and a decreased risk of diabetes mellitus in pregnancy, preeclampsia or eclampsia, and gestational hypertension. A long IPI (≥60 months) was associated with an increased risk of preterm birth (OR [95% CI]: 1.18 [1.11, 1.26] for VD and 1.39 [1.32, 1.47] for CS), placenta previa, postpartum hemorrhage, diabetes mellitus in pregnancy, preeclampsia or eclampsia, and gestational hypertension. Fertility policy changes had little effect on the association of IPIs and adverse maternal and neonatal outcomes. The estimated risk of preterm birth, low Apgar scores, SGA, diabetes mellitus in pregnancy, and gestational hypertension was more profound among women with previous term births than among those with preterm births or pregnancy loss.@*CONCLUSION@#For pregnant women with shorter or longer IPIs, more targeted health care measures during pregnancy should be formulated according to infant gestational age in previous pregnancy.

A study on rural-urban differences in neonatal mortality rate in China, 1996-2006.

OBJECTIVE: This study examined the differences in neonatal mortality rates between urban and rural areas in China. METHODS AND RESULTS: Data were taken from a database collected by the Chinese surveillance network for mortality of children under 5 years of age. The risk ratio of neonatal mortality for rural versus urban areas was between 2.2 and 2.7 for 1996-2006 and it declined to 2.0 in 2005-6. Pneumonia, birth asphyxia and preterm birth or low birth weight were the major contributors to the urban-rural differences in neonatal mortality, together with a relatively high proportion of home delivery and a relatively lower proportion of hospital treatment in rural areas. CONCLUSION: The urban-rural differences reflect the gap between the developed and the underdeveloped regions in China at that period. The neonatal mortality rate in China's rural areas could decrease further if continuous efforts are successful to increase the rates of hospital delivery in rural areas.