Snapshot A 31-year-old G1P0 woman presents to the obstetrician for her prenatal appointment at 22 weeks of gestation. She has had an uncomplicated pregnancy thus far, aside from occasional nausea in the first trimester. Her only complaint at this visit is that she has recently noticed increased vaginal discharge that is white and odorless. On speculum examination, the cervix is found to be dilated 2 cm, and white vaginal discharge is observed in the vaginal vault. On transvaginal ultrasound, her cervical length is measured to be 22 mm. Introduction Overview cervical insufficiency is the inability of the cervix to retain a pregnancy in the second trimester, in the absence of uterine contractions Epidemiology Incidence 0.5% in the general population of pregnant women 8% in women with a history of previous mid-trimester midcarriages Risk factors history of previous mid-trimester midcarriages repeated cervical dilations and/or cervical excisional procedures ETIOLOGY Pathophysiology Structural defect compromising the tensile strength of the cervix Premature cervical shortening may be secondary to other conditions (i.e., intrauterine infection and uterine overdistention) shortened cervix is defined as less than the 10th percentile (25 mm at 23-28 weeks) Presentation Symptoms most patients are asymptomatic pelvic pressure cramping back pain ↑ vaginal discharge Physical exam painless dilation of cervix delivery of fetus between 18-32 weeks of gestation Imaging Transvaginal ultrasonography indications routine cervical length screening is recommended for all women without a history of prior preterm birth should be performed between 16- 24 weeks for the most accurate and predictive measurement women with prior cervical excisional procedures or cervical dilations do not require additional screening following the first cervical length measurement findings short cervical length (< 25 mm) cervical funneling diltation of the internal part of the cervical canal Studies Fetal fibronectin testing can be used as a predictor of preterm delivery limited to women between 22-34 weeks of gestation, with intact fetal membranes and cervical dilatation < 3 cm positive fetal fibronectin may predict a higher risk of preterm delivery Treatment Medical progesterone supplementation indications women with a prior spontaneous preterm birth should be offered progesterone supplementation starting at 16-24 weeks of gestation and continuing up to 36 weeks of gestation women without a history of preterm birth and a short cervix Surgical cervical cerlage placement of sutures to improve the tensile strength of the cervix indications women with singleton gestations with any of the following: history of 2nd trimester pregnancy loss with painless cervical dilatation painless cervical dilatation in the 2nd trimester history of spontaneous preterm birth (< 34 weeks of gestation) and a short cervical length < 24 weeks of gestation NOT recommended in women with multiple gestations and a short cervix associated with an ↑ risk of preterm delivery