Socioeconomic status of pregnancy outcomes in Chongqing, Southwest China

Background: Findings of socioeconomic status (SES) effects on adverse pregnancy outcomes varies depending on pregnancy complications, SES indicators, countries, regions, and races. Our aim was to compare three SES indicators (maternal educational level, participant and partner’s income and maternal occupation) and to investigate the relationship with adverse pregnancy outcomes in Chongqing, Southwest China. Methods: Between 2015 and 2017, we analyzed data from 1273 women in Chongqing, China, enrolled in the Complex Lipids in Mothers and Babies (CLIMB) trial in which mothers received complex lipid supplementation during pregnancy. Information on SES (maternal educational level, participant and partner’s income and maternal occupation) was collected during face-to-face interviews using standard questionnaires. Pregnancy outcomes considered were gestational diabetes mellitus (GDM), premature rupture of membrane (PROM), cesarean section (C-section), preterm birth (PTB), macrosomia, low birth weight (LBW), large for gestational age (LGA), and small for gestational age (SGA). Logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for pregnancy outcomes in relation to SES. Supplementation had no effect on pregnancy outcomes, so our analysis did not subdivide our participants on this basis. Results: Women who were managers or professionals were less likely to suffer from macrosomia and LGA. After adjustment for potential confounders, the ORs for macrosomia and LGA were 0.44 (95% CI: 0.21, 0.95) and 0.48 (95% CI: 0.26, 0.89), respectively. Other pregnancy outcomes were not affected by maternal occupation. Moreover, no significant relationships were observed between the other two SES indicators (participant and partner’s income and maternal education) and adverse pregnancy outcomes. Conclusions: Our findings suggested that maternal occupation was a more reliable predictor of pregnancy outcomes than maternal education and participant and partner’s income.