Outpatient misoprostol cervical ripening without subsequent induction of labor to prevent post‐term pregnancy

Abstract

Sir, We read with great interest the article of Oboro and Tabowei (1), the first published randomized clinical trial (RCT) to assess the outpatient use of misoprostol in term pregnancies in a developing country. The potential benefit from such protocols is not to be demonstrated; the authors are to be congratulated for this well-conducted trial. However, it is not surprising to find a decrease in the mean time to delivery interval after 25 µg misoprostol administration. Even if the authors approached the question of the safety, they concluded that ‘outpatient administration of low-dose misoprostol can safely shorten the length of gestation in post-date pregnancies’. Although the use of misoprostol in term pregnancy ripening is now widely acceptable (2), safety of administration in an outpatient protocol is still of concern. Similar to others (3), the authors found a mean time to delivery of 4.5 ± 4.1 days with a shorter duration of labor of 6.1 ± 4.0 hr. As we previously noted in second-trimester pregnancy termination (4), such standard deviations reflect a large dispersion and make it difficult to predict the time of delivery which is particularly a matter of concern in a environment where women cannot promptly access to maternity. Consistently with this, McKenna et al. (3) in a randomized, double-blinded, placebo-controlled study using the same doses of misoprostol with a similar protocol of monitoring interestingly noted that more than one-third of the women delivered in the 24 hr following misoprostol ‘ripening’. This indicates that a large proportion of women labored at home. Even if the used regimen was slightly higher, Ramsey et al. (5) showed that more than half of women demonstrated an abnormal tracing event after 50 µg misoprostol administration. This raises concern about both outpatient management and the 1-hr monitoring. These authors also concluded that ‘early onset and frequent nature of the tracing abnormalities associated with misoprostol raise concern for the potential use of misoprostol for outpatient cervical ripening’. To the best of our knowledge, six studies investigated the use of misoprostol in term pregnancies on outpatient basis (1,3,6–9) for more than 450 patients; none of these studies reported a statistically significant increase in complication following misoprostol administration, because none of them has the power to detect it and absence of evidence is not evidence of absence (10). Although we do not share the opinion of some (11) who contraindicated the application of misoprostol in an outpatient setting, we strongly believe that a multicenter prospective RCT is needed with complications as primary outcome to asses safety of this demonstrated useful protocol particularly in developing countries.