The effectiveness of using misoprostol with and without letrozole for successful medical abortion: A randomized placebo-controlled clinical trial

Effect of misoprostol with and without letrozole on the induction of abortion for women with first-trimester missed abortion

OBJECTIVE

To determine whether addition of letrozole to a misoprostol-based abortion regimen can increase the rate of complete abortion.

METHODS

The randomized, placebo-controlled, double-blind trial enrolled women with missed abortion in the first trimester of pregnancy attending Sadooghi Hospital, Isfahan, Iran, from 2016 to 2018. The women were randomly assigned to the study group, which received 10 mg of letrozole daily for 3 days, followed by two doses of 800 μg of vaginal misoprostol at a 4-hour interval, or the control group, which received a placebo, followed by the same dose of misoprostol. Sonography was performed to check the abortion status.

RESULTS

In total, 120 women completed the study: 60 in the misoprostol plus letrozole group, and 60 in the misoprostol only group. Complete abortion was documented for 93 (77.5%) women: 48 (80.0%) in the misoprostol plus letrozole group and 45 (75.0%) in the misoprostol only group (P=0.80). The mean duration of induction in the misoprostol plus letrozole and misoprostol only groups was 7.35 ± 3.54 hours and 8.2 ± 3.8 4hours, respectively (P=0.21).

CONCLUSION

Administration of misoprostol alone was found to be as effective as the administration of misoprostol plus letrozole for first-trimester missed abortion.

The efficacy of letrozole supplementation for medical abortion: a meta-analysis of randomized controlled trials

INTRODUCTION

The efficacy of letrozole supplementation for medical abortion remains controversial. We conduct a systematic review and meta-analysis to explore the influence of letrozole supplementation for medical abortion.

METHODS

We searched PubMed, Embase, Web of Science, EBSCO, and Cochrane Library databases through October 2018 for randomized controlled trials (RCTs) assessing the effect of letrozole supplementation for medical abortion. This meta-analysis is performed using the random-effect model.

RESULTS

Six RCTs involving 555 patients are included in the meta-analysis. Overall, compared with control group for pregnant women, letrozole supplementation shows significantly increased complete abortion (RR = 1.38; 95% CI = 1.07-1.78; p = .01), and decreased estradiol (std. MD = -2.86; 95% CI = -4.45 to -1.27; p = .0004), but has no remarkable effect on induction-abortion time (std. MD = -1.03; 95% CI = -2.99-0.93; p = .30), progesterone (std. MD = 0.02; 95% CI = -0.30-0.34; p = .89), vaginal hemorrhage (std. MD = 1.84; 95% CI = 0.05-70.90; p = .74), nausea and vomiting (std. MD = 073; 95% CI = 0.44-1.21; p = .22).

CONCLUSIONS

Letrozole supplementation provides benefits to medical abortion in pregnant women.

Medical treatment for early fetal death (less than 24 weeks)

BACKGROUND

In most pregnancies that miscarry, arrest of embryonic or fetal development occurs some time (often weeks) before the miscarriage occurs. Ultrasound examination can reveal abnormal findings during this phase by demonstrating anembryonic pregnancies or embryonic or fetal death. Treatment has traditionally been surgical but medical treatments may be effective, safe, and acceptable, as may be waiting for spontaneous miscarriage. This is an update of a review first published in 2006.

OBJECTIVES

To assess, from clinical trials, the effectiveness and safety of different medical treatments for the termination of non-viable pregnancies.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (24 October 2018) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised trials comparing medical treatment with another treatment (e.g. surgical evacuation), or placebo, or no treatment for early pregnancy failure. Quasi-randomised studies were excluded. Cluster-randomised trials were eligible for inclusion, as were studies reported in abstract form, if sufficient information was available to assess eligibility.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. We assessed the quality of the evidence using the GRADE approach.

MAIN RESULTS

Forty-three studies (4966 women) were included. The main interventions examined were vaginal, sublingual, oral and buccal misoprostol, mifepristone and vaginal gemeprost. These were compared with surgical management, expectant management, placebo, or different types of medical interventions were compared with each other. The review includes a wide variety of different interventions which have been analysed across 23 different comparisons. Many of the comparisons consist of single studies. We limited the grading of the quality of evidence to two main comparisons: vaginal misoprostol versus placebo and vaginal misoprostol versus surgical evacuation of the uterus. Risk of bias varied widely among the included trials. The quality of the evidence varied between the different comparisons, but was mainly found to be very-low or low quality.Vaginal misoprostol versus placeboVaginal misoprostol may hasten miscarriage when compared with placebo: e.g. complete miscarriage (5 trials, 305 women, risk ratio (RR) 4.23, 95% confidence interval (CI) 3.01 to 5.94; low-quality evidence). No trial reported on pelvic infection rate for this comparison. Vaginal misoprostol made little difference to rates of nausea (2 trials, 88 women, RR 1.38, 95% CI 0.43 to 4.40; low-quality evidence), diarrhoea (2 trials, 88 women, RR 2.21, 95% CI 0.35 to 14.06; low-quality evidence) or to whether women were satisfied with the acceptability of the method (1 trial, 32 women, RR 1.17, 95% CI 0.83 to 1.64; low-quality evidence). It is uncertain whether vaginal misoprostol reduces blood loss (haemoglobin difference > 10 g/L) (1 trial, 50 women, RR 1.25, 95% CI 0.38 to 4.12; very-low quality) or pain (opiate use) (1 trial, 84 women, RR 5.00, 95% CI 0.25 to 101.11; very-low quality), because the quality of the evidence for these outcomes was found to be very low.Vaginal misoprostol versus surgical evacuation Vaginal misoprostol may be less effective in accomplishing a complete miscarriage compared to surgical management (6 trials, 943 women, average RR 0.40, 95% CI 0.32 to 0.50; Heterogeneity: Tau² = 0.03, I² = 46%; low-quality evidence) and may be associated with more nausea (1 trial, 154 women, RR 21.85, 95% CI 1.31 to 364.37; low-quality evidence) and diarrhoea (1 trial, 154 women, RR 40.85, 95% CI 2.52 to 662.57; low-quality evidence). There may be little or no difference between vaginal misoprostol and surgical evacuation for pelvic infection (1 trial, 618 women, RR 0.73, 95% CI 0.39 to 1.37; low-quality evidence), blood loss (post-treatment haematocrit (%) (1 trial, 50 women, mean difference (MD) 1.40%, 95% CI -3.51 to 0.71; low-quality evidence), pain relief (1 trial, 154 women, RR 1.42, 95% CI 0.82 to 2.46; low-quality evidence) or women's satisfaction/acceptability of method (1 trial, 45 women, RR 0.67, 95% CI 0.40 to 1.11; low-quality evidence).Other comparisonsBased on findings from a single trial, vaginal misoprostol was more effective at accomplishing complete miscarriage than expectant management (614 women, RR 1.25, 95% CI 1.09 to 1.45). There was little difference between vaginal misoprostol and sublingual misoprostol (5 trials, 513 women, average RR 0.84, 95% CI 0.61 to 1.16; Heterogeneity: Tau² = 0.10, I² = 871%; or between oral and vaginal misoprostol in terms of complete miscarriage at less than 13 weeks (4 trials, 418 women), average RR 0.68, 95% CI 0.45 to 1.03; Heterogeneity: Tau² = 0.13, I² = 90%). However, there was less abdominal pain with vaginal misoprostol in comparison to sublingual (3 trials, 392 women, RR 0.58, 95% CI 0.46 to 0.74). A single study (46 women) found mifepristone to be more effective than placebo: miscarriage complete by day five after treatment (46 women, RR 9.50, 95% CI 2.49 to 36.19). However the quality of this evidence is very low: there is a very serious risk of bias with signs of incomplete data and no proper intention-to-treat analysis in the included study; and serious imprecision with wide confidence intervals. Mifepristone did not appear to further hasten miscarriage when added to a misoprostol regimen (3 trials, 447 women, RR 1.18, 95% CI 0.95 to 1.47).

AUTHORS' CONCLUSIONS

Available evidence from randomised trials suggests that medical treatment with vaginal misoprostol may be an acceptable alternative to surgical evacuation or expectant management. In general, side effects of medical treatment were minor, consisting mainly of nausea and diarrhoea. There were no major differences in effectiveness between different routes of administration. Treatment satisfaction was addressed in only a few studies, in which the majority of women were satisfied with the received intervention. Since the quality of evidence is low or very low for several comparisons, mainly because they included only one or two (small) trials; further research is necessary to assess the effectiveness, safety and side effects, optimal route of administration and dose of different medical treatments for early fetal death.

Letrozole vs. Placebo Pretreatment in the Medical Management of First Trimester Missed Miscarriage: a Randomized Controlled Trial

Introduction

Misoprostol is used for the medical management of miscarriage as it is more effective in the early stages of pregnancy. Letrozole has an anti-estrogen effect and is used for the pretreatment of miscarriage with misoprostol.

Aim

The aim of this study was compare the efficacy and safety of letrozole with placebo pretreatment in the medical management of first trimester missed miscarriage.

Design

This was a prospective randomized case-control study.

Patients and Methods

Four hundred and thirty-eight women were randomly divided into two groups of 219; the placebo group received placebo tablets twice daily for 3 days, followed by 800 micrograms of misoprostol vaginally on the fourth day of enrolment, while the letrozole group received letrozole 10 mg twice daily for three days followed by 800 micrograms misoprostol administered vaginally. Symptoms and side effects were recorded, and the women advised to return to hospital if they experienced severe pain or bleeding or intolerable side effects and to report to hospital for a check-up one week after misoprostol administration. Ultrasound was done seven days after misoprostol administration to monitor outcomes. Surgical evacuation was carried out if medical management failed.

Results

There were significant differences between the two groups, with better outcomes found for the letrozole group in terms of rates of complete miscarriage, onset of vaginal bleeding, and interval between induction and onset of expulsion (p < 0.001). A higher rate of nausea and vomiting was reported for the letrozole group (p = 0.002). Differences between groups with regard to pre- and post-termination hemoglobin levels, fever, severe pain and severe bleeding needing evacuation were not statistically significant.

Conclusion

Adding letrozole to misoprostol improves the success rate and decreases the interval between induction and expulsion in cases of first trimester miscarriage; however, nausea and vomiting is higher with letrozole.

Fetal safety profile of aromatase inhibitors: Animal data

Aromatase inhibitors (AIs) are a class of drugs that act by blocking the production of estrogens from androgens. The current review concentrates on the prenatal developmental toxicity of AIs in experimental models. Available data indicate that AIs may affect pregnancy at human therapeutic or lower doses. The window of vulnerability to AIs is not limited to organogenesis, but also includes the preimplantation stage and fetal periods. Decreased embryo/fetal survival was the prominent treatment-related effect. Morphological anomalies noted in fetuses exposed to AIs included skeletal anomalies, abnormal head morphology, increased ano-genital distance in female fetuses, and minor urinary tract system anomalies. Placental enlargement was consistently reported in rats and non-human primates after maternal treatment with several AIs. In conclusion, data from basic scientific research suggest that low intensity exposure to AIs applied during a wide gestational window can profoundly affect prenatal development.