Repeated medical abortions and the risk of preterm birth in the subsequent pregnancy.
OBJECTIVE
The aim of this study was to determine the impact of repeated first trimester mifepristone-induced medical abortions on the risk of preterm birth in a subsequent pregnancy.


METHODS
This is a pregnancy-based cohort study. Clinical data were collected from seven public hospitals in Chengdu, China from January 2006 to December 2009. Pregnant women with one or more first trimester mifepristone-induced medical abortions, and/or one or more surgical abortions, or no previous induced abortions were included in the study. The women were monitored through pregnancy and birth. Samples for analysis included 18,024 singleton births.


RESULTS
The risk of preterm birth among women with one or more first trimester mifepristone-induced abortions did not differ significantly from the risk among primigravida women (OR 1.03, 95% confidence interval 0.53-1.63). The risks of preterm birth were higher among women with repeated surgical abortions in comparison to women with repeated medical abortions (OR 1.22, 95% confidence interval 1.03-1.64).


CONCLUSIONS
A history of multiple first trimester mifepristone-induced abortions is not associated with a higher risk of preterm delivery among singleton births in the first subsequent pregnancy.
Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, 610041 Sichuan, People's Republic of China. liaoh124@163.com
Hua
H
Liao
Qiang
Q
Wei
Lijun
L
Duan
Junli
J
Ge
Yuanyang
Y
Zhou
Weiyue
W
Zeng
D000021:Abortifacient Agents, Steroidal / Q000009:adverse effects*; D000028:Abortion, Induced / Q000009:adverse effects* / Q000379:methods; D000328:Adult; D002681:China / Q000453:epidemiology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D018811:Maternal Exposure / Q000009:adverse effects*; D015735:Mifepristone / Q000009:adverse effects*; D011247:Pregnancy; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First; D047928:Premature Birth / Q000453:epidemiology*; D012307:Risk Factors; D055815:Young Adult
D000021:Abortifacient Agents, Steroidal; D015735:Mifepristone