Late second trimester abortion with 16,16-dimethyl-trans-delta 2-PGE1 methyl ester (gemeprost)

Which factors influence the number of gemeprost pessaries used in inducing second-trimester abortions?

BACKGROUND

The course of second-trimester abortions with the intention to use gemeprost as the only abortifacient is described.

METHODS

The report is based on 278 consecutive second-trimester abortions, excluding missed abortions, during a 12-year period in a tertiary referral center. The women were treated with 1 mg gemeprost pessaries every fourth hour with a maximum of five applications during 24 h. If abortion had not occurred, a new treatment of gemeprost was prescribed after an interval of 12 h.

RESULTS

The median number of gemeprost pessaries used was 4 (range 1-16) and the mean number (+/-SD) 4.09 (+/-1.90). Abortion occurred within 24 h in 78% of the women and within 48 h in 96%. The efficiency of gemeprost was highly dependent on previous vaginal deliveries (p<0.001), with a mean number of applications of 4.63 (+/-2.04), 3.93 (+/-1.74), and 3.13 (+/-1.26) in those with none, one, and two or more previous vaginal deliveries, respectively. Previous spontaneous abortions were associated with a lower number of applications. Including previous vaginal deliveries and spontaneous abortions in a two-way analysis of variance (anova), only the number of spontaneous abortions was marginally significant (p=0.05). After excluding four patients with three or more spontaneous abortions from the analysis, the number of previous vaginal deliveries was significant (p=0.010) whereas that of spontaneous abortions became nonsignificant. Postprocedure complications were reported in 13% of the women.

CONCLUSION

The course of the abortions was dependent on previous vaginal deliveries and spontaneous abortions.

Prostaglandins for induction of second-trimester termination and intrauterine death

The introduction of synthetic prostaglandin has revolutionized the treatment protocol for induction of second-trimester abortion and intrauterine death. Gemeprost is the only licensed synthetic prostaglandin analogue for second-trimester abortion in the United Kingdom. However, it is expensive and needs to be stored in a refrigerator. Misoprostol is marketed for use in the prevention and treatment of peptic ulcer. It is inexpensive and can be stored at room temperature. It has been widely used for induction of second-trimester abortion and intrauterine death. Misoprostol, 400 microg given vaginally every 3hours, is probably the optimal regimen for second-trimester abortion. The combination of misoprostol and mifepristone significantly reduced the induction-to-abortion interval when compared with the misoprostol-only regimen. In addition, misoprostol can also be used as a cervical priming agent prior to dilatation and evacuation in second-trimester abortion.

Medical abortion in the second trimester

The introduction of prostaglandin analogues and mifepristone has changed the management of second trimester abortion in the last 2 decades. Gemeprost and misoprostol are the two most extensively studied prostaglandin analogues that are used in this period. The combination of either gemeprost or misoprostol with mifepristone is most effective. With these regimens, over 90% of women abort within 24 hours and the mean induction to abortion interval is about 6 hours. Mifepristone is expensive and is not available in many countries. Therefore, prostaglandin analogue-only regimens might be the only option. These regimens are still effective with an abortion rate of >90% in 48 hours. However, the induction to abortion interval (15 hours) is much longer. Intra-cervical tents can be used to shorten the induction to abortion intervals.