Objective: To study the current status of spontaneous abortion of primigravid women in Jiaxing areas of Zhejiang province of China.
Methods: We analyzed the data from both perinatal healthcare surveillance program and spontaneous abortion, collected in Jiaxing areas by the Institute of Reproductive and Child Health, Peking University. The study population consisted of 14 769 primigravid women (excluding induced abortion, ectopic pregnancy and molar pregnancy as outcomes) attempting to become pregnant who registered between 1993 and 1995.
Results: 1454 spontaneous abortion cases were identified, with the spontaneous abortion rate as 9.8% (95%CI: 9.3% - 10.3%). The mean gestational weeks at pregnancy diagnosis were 7.6 ± 2.1 weeks, the mean gestational weeks at miscarriage were (10.1 ± 3.1) weeks and the incidence of first-trimester (≤ 12 weeks) spontaneous abortion was 7.3% (95%CI: 6.8% - 7.7%), accounting for 73.7% of all the spontaneous abortion cases. A peak for risk of miscarriage was around 8 - 13 weeks, accounting for 37.7% of all spontaneous abortion. The observed multiple Cox regression model showed that increased spontaneous abortion rates were observed in women with age at pregnancy ≥ 30, being peasants and with higher education level.
Conclusion: The spontaneous abortion rate of primigravid women in Jiaxing areas was higher than in other areas of China. The maximum occurrence of spontaneous abortions was during period of 8-13 gestation weeks.