Use of misoprostol in first and second trimester abortion: a review

Comparison of Vaginal and Oral Doses of Misoprostol for Labour Induction in Post-Term Pregnancies

INTRODUCTION

Considering maternal complications, it is preferred to induce labour after 40 weeks. Labour induction is a procedure used to stimulate uterine contractions during pregnancy before the beginning of the labour.

AIM

The aim of this study was to compare oral misoprostol with vaginal misoprostol for induction of labour in post-term pregnancies.

MATERIALS AND METHODS

This double blind clinical-trial study was performed on 180 post-term pregnant women who were admitted to the labour ward of Besat Hospital Sanandaj, Iran in 2013-2014. Participants were equally divided into three groups using block randomization method. The induction was performed for the first group with 100 μg of oral misoprostol, for the second group with 50 μg of oral misoprostol, and for the third group with 25 μg of vaginal misoprostol. Vaginal examination and FHR was done before repeating each dose to determine Bishop Score. Induction time with misoprostol to the start of uterine contractions, induction time to delivery, and mode of delivery, systolic tachycardia, hyper stimulation and fetal outcomes were studied as well.

RESULTS

First minute Apgar scores and medication dosage of the study groups were significantly different (p=0.0001). But labour induction, induction frequency, mode of delivery, complications, and 5 minutes Apgar score in the groups had no significant difference (p>0.05). The risk of fetal distress and neonatal hospitalization of the groups were statistically significant (p=0. 02). There was no significant difference between the three groups in terms of mean time interval from the administration of misoprostol to the start of uterine contractions (labour induction), the time interval from the start of uterine contractions to delivery and taking misoprostol to delivery. From the administration of misoprostol to start of the uterine contractions the mean difference between time intervals in the three groups were not statistically significant.

CONCLUSION

Based on our findings it can be concluded that prescribing 100μg oral misoprostol is effective than 50 μg oral or 25 μg vaginal misoprostol in terms of induction time, maternal and neonatal outcomes in post- term pregnancy. However, the best dose and route should be decided according to evidence based information.

Adequacy and safety of buccal misoprostol for cervical preparation prior to termination of second-trimester pregnancy

OBJECTIVE

The objective of this retrospective, descriptive study is to assess the adequacy and safety of buccal misoprostol with and without laminaria for cervical preparation prior to second-trimester abortion.

METHODS

We analyzed Planned Parenthood Federation of America data from 2,218 elective dilation and evacuation (D&E) procedures conducted on women at 12 to 23 6/7 weeks of gestation from April 2002 to March 2003. Each woman received 400, 600 or 800 microg of buccal misoprostol with or without laminaria for preprocedural cervical preparation.

RESULTS

Of the patients, 62% received 400 mug, 32% received 600 microg and 6% received 800 microg of buccal misoprostol; 42.8% had laminaria inserted for phased cervical preparation. The adequacy of cervical dilation was 88.7%. The D&E procedure was completed during a single surgical procedure for 99.8%. The overall adverse event rate was 19.39 per 1,000 women, with a rate of 4.51 per 1,000 women for serious adverse events.

CONCLUSIONS

This descriptive study suggests that use of buccal misoprostol with or without laminaria is effective and safe. If buccal misoprostol eliminates or reduces the need for phased, multiday laminaria 1-3 days prior to the surgical procedure, then its use may offer service advantages such as reduced number of clinic visits and fewer pelvic examinations per woman.

High-dose vaginal misoprostol versus concentrated oxytocin plus low-dose vaginal misoprostol for midtrimester labor induction: a randomized trial

OBJECTIVE

This study was undertaken to compare the efficacy and side effects of a high-dose vaginal misoprostol regimen to concentrated intravenous oxytocin plus low-dose vaginal misoprostol for midtrimester labor induction.

STUDY DESIGN

Women at 14 to 24 weeks, with obstetric or fetal indications for delivery and no prior cesarean, were randomly assigned to receive either vaginal misoprostol 600 microg x 1, then 400 microg every 4 hours x 5 (group 1) or escalating dose-concentrated oxytocin infusions (277-1667 mU/min) plus vaginal misoprostol 400 microg x 1, then 200 microg every 6 hours x 2, then 100 microg x 1 (group 2). Analysis was by intent to treat. Primary outcomes were live birth rate and induction-to-delivery interval.

RESULTS

The intended sample size was 70 women per group; however, the trial was terminated at the initial interim analysis because of a highly significant difference in 1 of the primary study outcomes. Twenty women were assigned to group 1 and 18 were assigned to group 2. Median induction-to-delivery interval was significantly shorter in group 1 (12 hours, range 4-44 hours) versus group 2 (18 hours, range 7-36 hours; P = .01). Induction success rate at 12 hours was significantly higher in group 1 (60%) compared with group 2 (22%, P = .02). No significant difference was noted in the live birth rate between groups 1 and 2 (13%, 0%, P = .16). The incidence of retained placenta requiring curettage, chorioamnionitis, intrapartum fever, nausea, emesis, and diarrhea were similar between both groups.

CONCLUSION

Compared with concentrated oxytocin plus low-dose vaginal misoprostol, high-dose vaginal misoprostol significantly shortens midtrimester labor inductions.

Medical termination of pregnancy in the early first trimester

Surgical abortion using vacuum aspiration or dilatation and curettage has been the method of choice for termination of pregnancy up to 63 days' gestation since the 1960s. Over the last three decades many studies have explored the use of medical methods for inducing abortion at these gestations. Earlier regimens assessed the systemic and intrauterine injection of prostaglandins. This was followed in the 1980s by the introduction of the antiprogesterone, mifepristone. Since its introduction, the uptake of medical abortion has been steadily increasing in countries where it has been available for routine use. Most current clinical protocols require the use of prostaglandins in combination with anti-progesterones or antimetabolites. The safety, efficacy and acceptability of the medical regimen are now well established at all gestations of pregnancy. Provision of medical abortion increases the choice available to women, in particular those wishing to avoid surgery.

Vaginal misoprostol versus concentrated oxytocin and vaginal PGE2 for second-trimester labor induction

OBJECTIVE

To compare the efficacy, side effects, and complications of high-dose vaginal misoprostol with concentrated intravenous oxytocin plus low-dose vaginal prostaglandin (PGE(2)) for second-trimester labor induction.

METHODS

One hundred twenty-six consenting women with maternal or fetal indications for pregnancy termination and no prior cesarean delivery were randomly assigned to receive either vaginal misoprostol 600 microg 1x, 400 microg every 4 hours 5x (misoprostol group, n = 60) or escalating-dose concentrated oxytocin infusions (277-1,667 mU/min) plus vaginal PGE(2) 10 mg every 6 hours 4x (oxytocin group, n = 66). Both groups received concurrent extra-amniotic saline infusion for cervical ripening. Women who failed their assigned regimen received 20 mg of PGE(2) suppositories every 4 hours until delivery. Analysis was by intent to treat.

RESULTS

Demographic characteristics were similar between study groups. Median induction-to-delivery interval was significantly shorter in the misoprostol group (12 hours) than in the oxytocin group (17 hours; P <.001). There was a higher induction success rate at 24 hours in the misoprostol group (95%) than in the oxytocin group (85%; P =.06), although this difference did not reach statistical significance. The incidence of live birth (25% versus 17%), chorioamnionitis (5% versus 2%), and postpartum hemorrhage greater than 500 mL (3% versus 3%) were similar between the misoprostol and oxytocin groups, respectively. Diarrhea (2% versus 11%; P =.04), nausea/emesis (25% versus 42%; P =.04), and retained placenta requiring curettage (2% versus 15%; P =.008) were significantly less common in the misoprostol group when compared with the oxytocin group, respectively. Isolated intrapartum fever, however, was more frequent in the misoprostol group (67%) than in the oxytocin group (21%; P <.001).

CONCLUSION

Compared with concentrated oxytocin plus low-dose vaginal PGE(2), high-dose vaginal misoprostol is associated with significantly shorter induction-to-delivery intervals, fewer side effects, a lower incidence of retained placenta, and comparable incidence of live birth.

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

Medical abortion was performed in 461 consecutive women with gestational age </= 63 days using a regimen of mifepristone 600 mg followed 2 days later by gemeprost 1 mg vaginally. Success, defined as no surgical intervention, declined from 98.7% after 2 weeks to 94.6% after 15 weeks. The difference in short- and long-term success rates increased with increasing gestational age. The majority of failures (76%) were diagnosed more than 2 weeks after initiation of the abortion. At a 2-week follow-up visit, the women who turned out to be failures had a larger endometrial width, higher beta-hCG values and smaller reductions of beta-hCG than those treated successfully. To optimize comparison of success rates after different medical abortion regimens, we suggest that the criteria for success are stated clearly, that the success rates are stratified according to gestational age and that the indications for secondary intervention are categorized.

A randomized comparison of two regimens of misoprostol for second-trimester pregnancy termination

OBJECTIVE

The purpose of this study was to compare the efficacy and side effects of two different misoprostol regimens for second-trimester pregnancy termination.

STUDY DESIGN

We performed a randomized clinical trial in patients who were at 14 to 23 weeks of gestation and who were admitted for medical termination of pregnancy. All patients received 800 microg of vaginal misoprostol and were assigned randomly to 400 microg of oral misoprostol or 400 microg of vaginal misoprostol every 8 hours. Efficacy and side effects were compared. The mean induction time of the study group was compared with that of an historic control group that had received 400 microg vaginally every 12 hours.

RESULTS

Forty-three women were assigned randomly, 22 women to vaginal misoprostol and 21 women to oral misoprostol. Induction time and hospital stay were slightly shorter for the oral group; however, the differences were not significant. Side effects were similar for both groups.

CONCLUSION

After an initial 800 microg dose of vaginal misoprostol, a regimen of 400 microg of oral misoprostol every 8 hours is as effective as the same dose of vaginal misoprostol with no additional side effects, which provides a convenient alternative for midtrimester pregnancy termination.

Early medical termination pregnancy with methotrexate and misoprostol in lower segment cesarean section cases

AIM

The aim of the study was to investigate the efficacy of methotrexate and misoprostol for the medical termination of early pregnancy with previous cesarean section.

METHODS

Sixty-six pregnant women of 60 days or less in duration with previous one or two cesarean sections were selected. Each woman received intramuscularly a dose of methotrexate (50mg). Two to 3 days later, 800 microg of misoprostol was administered intravaginally. Repeat doses were used if there was no significant bleeding. An ultrasonography was done in each case after seven days. Subjects with continuing pregnancies or excessive bleeding had a surgical abortion. A successful medical abortion was defined by vaginal bleeding without surgical intervention and a negative transvaginal ultrasound. Side-effects were noted.

RESULTS

Complete abortion occurred in 87.9% cases after first dose of misoprostol, and 6.1% cases had complete abortion after second dose, so out of 66 cases 62 (94%) had a successful medical abortion. Four (6%) subjects required surgical intervention; one for continued pregnancies, one for missed abortion, and two for excessive bleeding. The complete abortion rate was higher for early gestations: 30/30 (100%) at < or = 45 days gestation, 28/30 (93.3%) at 46-50 days gestation, and 2/6 (33.3%) from 50 to 63 days gestation. Vaginal bleeding lasted 15 +/- 7 days. Gastrointestinal side-effects were uncommon, mild, and brief. There was no case of uterine rupture.

CONCLUSION

Medical abortion using methotrexate with misoprostol is safe, cheap, and effective for early pregnancy termination through 8 weeks' gestation even with previous cesarean section.

High-dose oral misoprostol for mid-trimester pregnancy interruption

OBJECTIVE

To evaluate the efficacy of high-dose oral misoprostol for mid-trimester pregnancy interruption.

METHODS

We reviewed our experience with high-dose oral misoprostol for mid-trimester pregnancy interruption from November 1995 to May 1999. Patients undergoing labor induction for intrauterine fetal demise or medically indicated pregnancy termination at 13-32 weeks of gestation with a non-dilated cervix were evaluated. Patients received 400 microg misoprostol orally every 4 h. Women undelivered within 24 h were considered failures and were treated with high-dose oxytocin as previously described. For comparison, a group of women treated with high-dose oxytocin were evaluated.

RESULTS

Forty-seven pregnancies were managed with misoprostol (n = 23) or high-dose oxytocin regimen (n = 24). Both groups were similar with respect to induction indication, gestational age, maternal age/parity, laminaria use, and initial cervical dilation. Induction-to-delivery interval (mean +/- SD) was significantly shorter in the misoprostol cohort (15.2 +/- 6.7 h) compared with those treated with oxytocin (21.7 +/- 11.0 h; p = 0.02). Additionally, a significantly greater percentage of women treated with misoprostol delivered within 24 h (91.0%) compared with the oxytocin group (62.0%; p = 0.04). Adverse outcomes and side effects were not significantly different between the study groups.

CONCLUSION

High-dose oral misoprostol is more effective than concentrated oxytocin infusion for mid-trimester pregnancy interruption.

Buccal misoprostol as cervical preparation for second trimester pregnancy termination

The objective of the study was to assess the efficacy of cervical preparation with misoprostol or laminaria suction abortion up to 18 weeks gestation. The study was conducted among a consecutive case series of patients presenting for dilatation and evacuation at a single center. Cervical preparation was effected by either 600 mg buccal misoprostol (n = 32) or laminaria (n = 78). Dilatation and evacuation was then performed using vacuum aspiration, with fetal parts or placenta removed as necessary with appropriate forceps. The principle outcome of interest was procedure time. Complete abortion was effected in 100% of the cases. In all cases, the cervix was adequately prepared to allow either the introduction of a size 14-mm suction cannula or was easily dilated to this diameter. Group size was sufficient for detection of a 20% difference in mean procedure time with 80% power (calculated with two separate standard deviations for procedure time). Procedure times were not significantly different when misoprostol was used compared to laminaria for cervical preparation. It is concluded that the use of misoprostol to provide cervical preparation in second trimester abortion procedures appeared effective and offers an alternative to laminaria. Buccal misoprostol should be more widely investigated for this purpose.

Inhibition of progesterone secretion with trilostane for mid-trimester termination of pregnancy: randomized controlled trials

BACKGROUND

Progesterone is central to the maintenance of pregnancy, and is thus the ideal target for fertility regulation. Two mechanisms by which progesterone can be targeted are: receptor blockade and reduction of progesterone production through enzyme inhibition. Mifepristone, a receptor blocker, is usually given as 'pretreatment' prior to prostaglandin administration in mid-trimester termination of pregnancy (TOP). Unfortunately, there are difficulties accessing mifepristone in developing countries, and TOP is therefore performed using prostaglandins alone, which results in unacceptably long induction-to-abortion intervals. Trilostane is a 3beta-hydroxysteroid dehydrogenase inhibitor which reduces progesterone production. In these mid-trimester studies it is evaluated as a method of pretreatment prior to misoprostol administration.

METHODS

Three consecutive randomized controlled trials comparing different trilostane regimens for pretreatment were performed. In study 1, trilostane was compared with placebo; in study 2, two doses of trilostane were compared (1080 mg and 720 mg); in study 3, the effect of adding danazol to trilostane as combination therapy was evaluated. The primary outcome in all the studies was the induction-to-abortion interval. Serum progesterone, estradiol and cortisol were measured serially during treatment.

RESULTS

In study 1, 48 women were randomized. The median induction-to-abortion interval was 9 h in the trilostane group and 18.5 h in the placebo group (P < 0.0001). Progesterone and estradiol production was significantly reduced in the women receiving trilostane, with maintenance of diurnal cortisol variation. Twenty-eight women were randomized in study 2, which demonstrated that there was no significant difference in the induction-to-abortion interval using 1080 mg and 720 mg trilostane when compared with the higher doses used in study 1. Study 3, in which 40 women were included, failed to show any additional benefit using combination therapy with danazol and trilostane.

CONCLUSIONS

Trilostane is an effective pretreatment agent in mid-trimester TOP.

Outpatient second trimester pregnancy termination

We evaluated the efficacy of initiating a second trimester medical abortion outside of a health care facility using patient self-administered serial intravaginal misoprostol. Patients scheduled for second trimester medical termination of pregnancy were randomized to an inpatient or outpatient group. Both groups received a single 200-microg vaginal misoprostol tablet every 6 h. No other abortifacients were used. The home group self-administered the misoprostol and returned to the hospital for clinical reasons or after 24 h and again at 48 h. Forty-two women were assigned to the inpatient and 45 to the outpatient groups. There was no difference between the groups in demographics or indications for terminations. The median hours from first misoprostol to delivery of the fetus was 12 and 14 (inpatient versus outpatient, respectively; p = 0.28). The total median hours in hospital were 24 versus 11 (inpatient versus outpatient, respectively; p <0.05). Two patients (4%) in the outpatient group delivered the fetus outside of the hospital. There were no cases of hemorrhage in either group. Outpatient initiation of second trimester medical termination with self-administered misoprostol is effective and decreases time of hospitalization.

Strategies to reduce maternal mortality worldwide

The challenge of reducing maternal mortality is increasingly being addressed by area-based efforts to improve access to care of obstetric emergencies. Improving coverage and quality of skilled attendance at birth is also being increasingly emphasized. Post-abortion care, better reproductive health services for adolescents, and improved family planning care are important ingredients in maternal mortality reduction. New developments in malaria, nutrition, violence and HIV/AIDS in relation to maternal health are highlighted, as well as measurement issues. Maternal mortality reduction is also being promoted today by using a human rights approach.

Cardiovascular effects of intravaginal misoprostol in the mid trimester of pregnancy

OBJECTIVE

Our aim was to evaluate the cardiovascular effects of high-dose intravaginal misoprostol administration by means of transthoracic electrical bioimpedance monitoring.

STUDY DESIGN

Healthy women undergoing mid trimester pregnancy interruption with intravaginal misoprostol were eligible for this prospective observational study. Baseline blood pressure was obtained for 1 hour and transthoracic electrical bioimpedance monitoring was performed before misoprostol administration, 600 microg vaginally. Posttreatment assessments were made every 15 minutes for a total of 4 hours, with patients in a left lateral recumbent position. Heart rate, mean arterial pressure, cardiac index, stroke index, systemic vascular resistance index, and end-diastolic volume index were determined. Measurements were averaged for 30-minute intervals and reported as mean +/- SD. Statistical analyses included the paired t test and repeated-measures analysis of variance.

RESULTS

Nine women consented to have transthoracic electrical bioimpedance monitoring, and no statistically significant changes in any of the measured cardiac parameters for the 4-hour monitoring interval were noted. Direct comparisons between the pretreatment and 2-hour posttreatment intervals (reported time peak of blood misoprostol levels) also revealed no significant differences in the cardiovascular index values.

CONCLUSION

High-dose intravaginal misoprostol in the mid trimester does not alter maternal cardiac function as measured by transthoracic electrical bioimpedance.