Pessary for short cervix may reduce risk of twin preterm birth

1. In women with short cervix and ongoing twin pregnancy, combination of pessary and vaginal progesterone was associated with pregnancy prolongation.

2. The incidence of adverse neonatal outcomes was lower in women with pessary and vaginal progesterone compared to matched controls.

Evidence Rating Level: 2 (Good)

Study Rundown: With the popularization of assisted reproductive technologies, twin births now account for nearly four percent of all live births in the United States. More than half of all twin deliveries are premature (<37 weeks gestation), which contributes to the disproportionately higher incidence of neonatal morbidity and mortality of twin compared to singleton deliveries. Short cervical length on ultrasound, otherwise known as sonographically short cervix (<2cm), has been demonstrated to be associated with and predictive of preterm birth in both singleton and twin pregnancies, but unfortunately the interventions available to reduce this risk in twin pregnancies has been poorly studied. Some evidence suggests that vaginal progesterone may help, but other interventions including bedrest, cerclage (a stitch used to hold the cervix closed), and tocolytics (anti-contraction medications) have been shown to be ineffective prolonging twin pregnancies complicated by sonographically short cervix.

A cervical pessary is a small plastic ring placed around the opening of the cervix to theoretically hold it closed. Studies of its use in singleton pregnancies with short cervix suggest it may be an effective intervention, but to date no study has specifically assessed its use in twin pregnancies with a short cervix. In this small retrospective study, researchers at one maternal-fetal medicine practice compared pregnancy and neonatal outcomes in twin pregnancies complicated by sonographically short cervix in a 1:3 ratio of women who received a cervical pessary and vaginal progesterone versus women who received only vaginal progesterone.

Key findings demonstrated that the use of a pessary in addition to vaginal progesterone was associated with pregnancy prolongation and incidence of adverse neonatal outcomes. Strengths included matching controls by gestational age and cervical length, which reduced selection bias. Limitations included retrospective design and analysis, small sample size and lack of randomization. Replication of results in a large, randomized, prospective trial would lend credence to the findings presented herein and better establish risks and benefits associated with cervical pessary placement.

Click to read the study in Obstetrics & Gynecology

Click to read the accompanying editorial

Relevant Reading: Cervical pessaries for prevention of preterm birth in women with a multiple pregnancy (ProTWIN)

In-Depth [retrospective cohort study]: All women with a cervical length of <20 mm at <28 weeks of gestation receiving care for ongoing twin pregnancy at a single maternal-fetal medicine practice were included in the analysis. All women were prescribed vaginal progesterone at the time of diagnosis as per standard of care. Starting in 2013, the practice began offering pessary placement in addition to progesterone. Patients who received a pessary (n = 21) were compared to controls (n = 63), matched by cervical length and gestational age in a 1:3 ratio. A range of pregnancy and neonatal outcomes were assessed using Chi-square, Fisher exact, and Student’s t test as appropriate.

Among women with a sonographically short cervix and ongoing twin pregnancy, those who received a pessary in addition to vaginal progesterone experienced a longer interval to delivery (65 vs. 24 days, p = 0.025) and were less likely to delivery before 32 weeks (4.8% vs. 28.6%, p = 0.05). When evaluating neonatal outcomes, there was a lower incidence of severe neonatal morbidity (9.5% vs. 34.9%, p = 0.04) among women with pessary compared to matched controls. There were no adverse events noted in the pessary group.

Image: PD

©2015 2 Minute Medicine, Inc. All rights reserved. No works may be reproduced without expressed written consent from 2 Minute Medicine, Inc. Inquire about licensing here. No article should be construed as medical advice and is not intended as such by the authors or by 2 Minute Medicine, Inc.