475: Postpartum cervical insufficiency - a novel cause or consequence of preterm birth?

Abstract

A short cervix is a risk factor for preterm delivery (PTD). Cervical recuperation postpartum however, is still an enigma. We aimed to establish the normal cervical recovery postpartum and investigate differences in cervical recuperation regarding term vs PTD, the influence of parity, mode of delivery and cervical manipulations. The study was conducted between June 2016 to June 2018. Following informed consent, trans-vaginal cervical length (CL) measurements were performed by a single observer (R.L) at 8, 24 and 48 hours postpartum. CL at the second trimester, prophylactic progesterone, demographic characteristics, obstetric history, parity, delivery outcomes, previous cervical manipulations and induction mode, were obtained from the patient's’ medical records. Our cohort included 714 women. The average CL, 48 hours postpartum, following term deliveries was 35.2± 3.5 mm. Parity: The most rapid cervical recovery was demonstrated following the 2nd delivery (39.7±2.5 mm). A significant delay in cervical recovery was observed from the 4th delivery and above (27.8±2.7 mm; p=0.013) (Fig 1A). Preterm delivery: Women delivered before 34 weeks of gestational (n=119) demonstrated an abnormal cervical recovery when compared to deliveries between 34-37 (n=97) weeks and term deliveries (n=498) (17.2±1.9 mm vs 32.4±3.6 mm vs 35.2±3.5 mm respectively P<0.0001) (Fig 1B). No differences were demonstrated between the groups regarding demographic characteristics and CL at midtrimester. Mode of induction: 156 patients underwent medical induction (Dinoprostone or Pitocin) and 88 underwent mechanical induction by cervical ripening balloon (CRB). Abnormal cervical recovery was demonstrated in the CRB group (26.3±1.9 mm vs. 35.2±2.7 mm respectively P=0.012) (Fig 1C). This study gives a novel insight regarding cervical recuperation postpartum. Nomograms of postpartum cervical recovery have been firstly established. Early spontaneous PTD is associated with pathological cervical recovery which might imply “true” cervical insufficiency. Increased parity and mechanical inductions may cause damage to the cervix Although the clinical implications of delayed postpartum cervical recuperation has not been elucidated, it might imply future cervical insufficiency and possible increased risk of preterm birth.