Objective  To investigate the clinical characteristics of pregnant woman in advanced maternal age and the effect of advanced maternal age and pregnancy tests on comorbidity and complications of pregnancy.

  Methods  A total of 111 804 pregnant women from six urban areas of Nanning City were selected and divided into low maternal age group (age<35 years old) and advanced maternal age group (age≥35 years old). The clinical characteristics, pregnancy comorbidity or complications of pregnant women were analyzed retrospectively.

  Results  The proportions of cases with early pregnancy examination and number of pregnancy tests ≥5 in the advanced maternal age group were significantly lower than those in the low maternal age group, while the proportions of cases with number of pregnancy ≥3, history of childbirth, history of cesarean section, artificial or spontaneous abortion ≥3 times, reproductive technology assisted pregnancy, multiple pregnancy, exposure to suspicious teratogenic substances during pregnancy and severe high-risk pregnancy were significantly higher than those in the low maternal age group (P<0.05). Multivariate Logistic regression analysis showed that advanced maternal age was the risk factor for gestational hypertension, gestational diabetes, hyperthyroidism or hypothyroidism, anemia, ovarian or uterine tumors, preeclampsia, placental abruption, placenta previa, premature rupture of membranes, abnormal placenta, postpartum hemorrhage and amniotic fluid, while pregnancy tests ≥5 times was the protective factor for placental abruption and premature rupture of membranes in pregnant women with advanced maternal age (P<0.05).

  Conclusion  Advanced maternal age can increase the risk of pregnancy comorbidity and complications, so we should strengthen the perinatal health care management services for pregnant women with advanced maternal age.