Changing trends of adverse pregnancy outcomes with maternal age in primipara with singleton birth: A join point analysis of a multicenter historical cohort study in China in 2011‐2012

Abstract

Introduction Adverse pregnancy outcomes are related to two opposite maternal factors, youth and aging. However, the change in trend of specific outcomes with childbearing age is unknown. The aim of this study was to investigate the changing trend of various maternal and neonatal outcomes with maternal age from 17 to 44 years. Material and methods Data were extracted from the medical records from 2011‐2012 of 39 public hospitals of 14 cities in China. The eligibility criteria were primiparity and singleton birth. Join point regression analysis was used to estimate the percent change per year of age (PCA) to explore the trends of adverse pregnancy outcomes with regard to maternal age and to identify the join point of maternal age when the trend was changed. Results A total of 89 171 women were eligible for analysis. There were four categories of trend styles. Continuously increasing trends were linear for placenta previa (PCA, 0.1%), placenta implantation (PCA, 0.09%) and postpartum hemorrhage (PCA, 0.22%), and nonlinear for gestational diabetes mellitus with one join point of 23 years (PCA, 0.17% and 0.71%) and cesarean section with four join points of 25, 28, 31 and 36 years (PCA, 1.39%, 0.34%, 1.51%, 3.49% and 0.94%). Continuously decreasing trends were linear for intrahepatic cholestasis (PCA, −0.02%) and nonlinear for anemia with one join point of 28 years (PCA, −0.49% and −0.04%). The bidirective trends were downward to upward for preterm birth (PCA, −2.93%, −0.36% and 0.38%), hypertension in pregnancy (PCA, −0.09%, 0.47%), low birthweight (PCA 0.51% and 0.38%), low 1‐minute Apgar score (PCA, −0.28% and 0.07%), low 5‐minute Apgar score at (PCA, −0.10% and 0.06%) and neonatal intensive care unit admission (PCA, −1.92%, −0.07% and 0.12%) with a nadir age of 28 years. The bidirective trend was upward to downward for macrosomia (PCA, 0.39% and −0.11%), with a peak age of 30 years. Conclusions The changes in the trend of specific outcomes were different with maternal age, which means that youth, aging or both could affect the outcomes.

The Influence of Maternal BMI on Adverse Pregnancy Outcomes in Older Women

“…In our study, at the same time, younger and older age was associated with higher adjusted odds ratios of PE, IUGR, and preterm birth <37th week, which is consistent with reports in the literature [17][18][19]32], but the number of PE (n = 24) and IUGR (n = 21) cases in our the cohort was small. PE and IUGR often coexist, and in their pathogenesis the role of placental ischemia in early pregnancy is taken into account.…”

“…Our core results (higher risk of pregnancy complications in older mothers, and associations of young age with some pregnancy outcomes) are consistent with several reports in the world literature [4,[17][18][19][20][21]28]. However, some studies have found no correlation between maternal age and pregnancy outcomes [2,22].…”

“…In our cohort, the risk of gestational hypertension (GH), gestational diabetes mellitus (GM), and caesarean section increased along with increasing maternal age, suggesting that aging influenced these outcomes, and many studies have found the same profile [18]. The rate of cesarean sections in our cohort (without a separate analysis of individual indications) was high (47.2% in women ≥35 years old and 36% in those <35 years old), which is consistent with the literature [4].…”

“…However, the results of the research available in the literature are debatable and controversial. Many studies have shown risks of adverse pregnancy outcomes and complications increasing along with maternal age [17][18][19][20][21]. However, other studies have not found these associations [2,22,23].…”

Dysregulation of bile acids increases the risk for preterm birth in pregnant women

“…Characteristics of pregnant women, sTBA levels, and PTB rates. Among the characteristics of the subjects, maternal age [20][21][22][23] , and pre-pregnancy body mass index (BMI) [24][25][26][27] had significant impacts on PTB. We performed correlation analyses between sTBA concentrations and PTB rates in subjects with different maternal ages or pre-pregnancy BMIs.…”