Mifepristone–misoprostol midtrimester abortion: impact of gestational age on the induction-to-abortion interval
Received 8 September 2009; received in revised form 19 September 2009; accepted 5 October 2009. published online 13 November 2009.
Abstract
Background
This study was conducted to explore the effect of gestational age (GA) on the induction-to-abortion interval of mifepristone–misoprostol midtrimester termination of pregnancy (TOP) regimen.
Study Design
This study involved a consecutive series of 270 pregnancies between 12.0 and 22.6 weeks that have undergone legal TOP from April 2006 to June 2009. All women received a single oral dose of 200 mg mifepristone and, 36–48 h later, a course of misoprostol (an initial vaginal dose of 800 mcg plus four oral doses of 400 mcg at 3-hourly intervals). Treatment was considered to be a failure if abortion did not occur within 24 h. The impact of GA, parity and maternal age on the induction-to-abortion interval was assessed by means of Cox regression.
Results
Overall, the mean GA at TOP was 18.0 weeks. The mean induction-to-abortion interval was 9.8 h (SD=8.2 h; range=1–50 h), and 246 women (91%) aborted successfully within 24 h. GA at TOP and parity were the only two variables independently associated with the induction-to-abortion interval. The mean induction-to-abortion interval was increased by about 50% in patients undergoing TOP between 20.0 and 22.6 weeks (12.9 h, SD=8.9), as compared with those at 16.0–19.6 weeks (7.8 h, SD=5.9) and 12.0–15.6 weeks (8.2 h, SD=8.3) (p<.001). The effect of parity on the induction-to-abortion interval was more modest, with a 20% increase in induction-to-abortion interval in nulliparous (10.1 h, SD=9.1), as compared with women with a previous live birth (8.1 h, SD=6.7).
Conclusions
The mean induction-to-abortion interval increases by 4 h after 20 weeks GA. This information may be relevant for counseling and planning of the procedure.
aDepartment of Maternal–Fetal Medicine, ICGON, Hospital Clínic, University of Barcelona and Centre for Biomedical Research on Rare Diseases (CIBERER), 08028 Barcelona, Spain
bDepartment of Pharmacy, ICGON, Hospital Clínic, University of Barcelona and Centre for Biomedical Research on Rare Diseases (CIBERER), 08028 Barcelona, Spain
Corresponding author. Department of Maternal–Fetal Medicine, Institut Clinic de Ginecologia, Obstetricia i Neonatologia, Hospital Clínic, 08028 Barcelona, Spain. Tel.: +34 678451555; fax: +34 93 2275605.
ABSTRACT