[Analysis of 649 cases of stillbirth in third trimester].

To analyze the risk factors of stillbirth in third trimester. Clinical data of 649 cases of stillbirth in third trimester were analyzed retrospectively in 22 hospitals of Haidian district from October 2011 to September 2016, including the incidence, the maternal profile, the perinatal care during pregnancy and the causes of stillbirth. (1) The incidence of stillbirth in third trimester in Haidian district from October 2011 to September 2016 was 0.293%(649/221 845). While the incidence in floating pregnant women (0.349%, 342/97 939) was higher than that in the residence (0.248%, 307/123 906), with statistically significant difference (χ(2)=19.178, <0.01). The incidence of stillbirth in multiple pregnancy(0.201%, 89/4 264) was higher than that in singleton pregnancy (0.257%, 560/217 581), with statistically significant difference(χ(2)=4.690, <0.01). There was no statistically significant difference in the incidence of stillbirth between male (0.300%, 347/115 632) and female fetuses (0.284%, 302/106 205; χ(2)=0.467, >0.05).(2)Among the 649 cases, the floating population accounted for the majority of those who never had prenatal visit (84.0%, 21/25), or less than 5 visits (80.7%, 125/155), or the first visit was beyond 13 gestational weeks(66.0%, 165/649). The causes of stillbirth in order were fetal factors (30.7%, 199/649), maternal factors(28.0%, 182/649), umbilical cord factors (20.0%, 130/649), unexplained factors (17.6%, 114/649) and placental factors (3.7%, 24/649). Birth defects, pregnancy hypertensive disorders, umbilical cord entanglement or torsion were the most important factors, accounting for 22.8%(148/649), 17.4%(113/649), 17.3%(112/649), respectively. The floating pregnant women are key population of stillbirth in third trimester. Maternal care and education should be strengthened in this population. The prevention of birth defect, better prenatal care in women with complications, and close monitor during labor are the key measures to reduce the incidence of stillbirth in third trimester.