Objective To analyze changes and correlations in the pregnancy characteristics of parturients and adverse birth outcomes of newborns in a tertiary grade A hospital from 2017 to 2022, and provide a basis for targeted prevention of adverse birth outcomes in newborns.

Methods  Medical records of obstetric deliveries from January 1, 2017, to December 31, 2022, were retrospectively collected. Descriptive analysis was used to examine the pregnancy characteristics of parturients and adverse birth outcomes of newborns. Univariate and multivariate analyses were conducted to explore the relationship between these factors during this period.

Results The final analysis included data from 93547 newborns and 88857 corresponding mothers. From 2017 to 2022, the number of mothers and newborns at our hospital showed an overall increasing trend. The main reproductive age for women in this region was concentrated between 30 and 34 years. The proportion of older mothers (≥ 35 years) showed a general downward trend, and this difference was statistically significant (χ²_trend = 13.261, P < 0.001). Except for cesarean section, the risks of preterm birth, low birth weight (LBW), macrosomia, small for gestational age infant (SGA), and large for gestational age infant (LGA) in this region showed an overall downward trend, with statistically significant differences (P < 0.05). Multivariate logistic regression analysis showed that, compared with mothers under 30 years, the risk of cesarean section for newborns was 1.339 times higher in the 30-34 age group (adjusted odds ratio aOR = 1.339, 95% CI: 1.297-1.382) and 2.646 times higher in the ≥ 35 age group (aOR = 2.646, 95% CI: 2.532-2.765). For LGA risk, only mothers aged ≥ 35 years showed an increased risk for newborns (aOR = 1.111, 95% CI: 1.049-1.178, P < 0.001). The risks of cesarean section, preterm birth, and macrosomia in the multiparous group were 1.151 times (aOR = 1.151, 95% CI: 1.114-1.189), 1.558 times (aOR = 1.558, 95% CI: 1.486-1.633), and 1.595 times (aOR = 1.595, 95% CI: 1.527-1.688) those in the primiparous group, respectively, while the risk of SGA in the multiparous group was lower than in the primiparous group (aOR = 0.684, 95% CI: 0.655-0.715). The risks of cesarean section, macrosomia, and LGA in the in vitro fertilization (IVF) group were 2.295 times (aOR = 2.295, 95% CI: 2.170-2.427), 1.274 times (aOR = 1.274, 95% CI: 1.122-1.447), and 1.300 times (aOR = 1.300, 95% CI: 1.216-1.391) those in the natural conception group, respectively, but the risk of SGA was lower than in the non-IVF group (aOR = 0.774, 95% CI: 0.729-0.821).

Conclusion  From 2017 to 2022, the characteristics of pregnant women in our hospital changed, and the risk of some adverse neonatal outcomes showed a decreasing trend during this period. Additionally, neonatal birth outcomes among different high-risk groups (women aged 35 or older, multiparous women, and women who conceived with assisted reproductive technology) exhibited distinct characteristics.