Painless cervical dilation with "hourglass membranes": conservative management

Cervical competence is currently conceived as a continuous biological process with progressive degrees of insufficiency, this substituting the traditional vision of cervical competence as being present or absent. The most extreme expression of cervical insufficiency is known as "hourglass membranes". Currently no consensus exists regarding the treatment of pregnancies complicated by the protrusion of amniotic membranes; however, the majority of authors agree on recommending bed rest and performing cervical cerclage, known as "emergent cerclage."

We describe a series of clinical cases corresponding to second-trimester pregnancies with cervical dilation and prolapsed amniotic membranes that were admitted to our hospital, managed with conservative treatment. All patients received the same basic treatment: intravenous fluid therapy for hydration, a single-oral-dose of azithromycin and intravenous antibiotic therapy for 7 days, vaginal micronized progesterone and indomethacin administrated orally.

Mean gestational age at diagnosis was 22.5 weeks with an extension of pregnancy between 2.1 and 16 weeks, with eight patients (72.72%) who extended their pregnancy for more than 8 weeks. In all cases, live fetuses were obtained, with favorable evolution.

Despite our limited experience, resulting from the low number of cases presenting, our results encourage us to propose conservative management in pregnancies complicated with a dilated cervix and membranes protruding into the vagina, as a reasonable alternative to surgical emergency cervical cerclage, which is currently considered the therapy of choice when extreme cervical shortening occurs in the second trimester of pregnancy.