Consecutive cervical length measurements as a predictor of preterm cesarean section in complete placenta previa

Abstract

In women with complete placenta previa, decrease in cervical length to ≤35 mm was associated with increased risk of preterm cesarean section due to massive hemorrhage.

Using ultrasound in the clinical management of placental implantation abnormalities

“…Approximately 80% of the patients with cervical length >30 mm went to term (!37 weeks) as compared to only 31% of those with cervical lengths 30 mm (P < .001), the probability of bleeding necessitating delivery ranging from as low as 10-20% for cervical lengths of 50-60 mm and as high as 60-100% for cervical lengths <10-15 mm. 16 Sekiguchi et al, 19 who followed patients with placenta previa with serial cervical length measurements until 37-38 weeks' gestation, reported similar findings. They chose a cervical length cutoff of 35 mm to differentiate between those who required preterm cesarean delivery vs those who went to term.…”

“…However, they also analyze their data according to various cervical length cutoffs; 72% (33/46) of patients with cervical length >30 mm went to term as compared to only 28% (13/46) when the cervix was 30 mm (odds ratio, 3.81; 95% confidence interval, 1.37e10.62; P ¼ .018). 19 Zaitoun et al 17 reported similar findings regarding the value of cervical length as predictor of bleeding. They found that patients with placenta previa and cervical length >30 mm had fewer emergency cesarean deliveries <36 weeks (10% vs 46%, P ¼ .002) and higher mean birthweights (2.8 vs 1.9 kg, P ¼ .003) as compared to those with cervical lengths 30 mm.…”

Placenta accreta and emergency cesarean delivery correlates to cervical length and transcervical placental thickness measurement

“…However, they also analyze their data according to various cervical length cutoffs; 72% (33/46) of patients with cervical length >30 mm went to term as compared to only 28% (13/46) when the cervix was <30 mm (odds ratio=3.81; 95% CI, 1.37-10.62; p=0.018). 28 Zaitoun et al reported similar findings regarding the value of cervical length as predictor of bleeding. 29 They found that patients with placenta previa and cervical length >30 mm had fewer emergency CD <36 weeks (10% versus 46%, p=0.002) and higher mean birth weights (2.8 versus 1.9 kg, p=0.003) as compared to those with cervical lengths ≤ 30 mm.…”

“…Sekiguchi et al who followed patients with placenta previa with serial cervical length measurements until 37-38 weeks' gestation reported similar findings. 28 They chose a cervical length cutoff of ≤35 mm to differentiate between those who required preterm CD versus those who went to term. However, they also analyze their data according to various cervical length cutoffs; 72% (33/46) of patients with cervical length >30 mm went to term as compared to only 28% (13/46) when the cervix was <30 mm (odds ratio=3.81; 95% CI, 1.37-10.62; p=0.018).…”

The Rate of Cervical Length Shortening in the Management of Vasa Previa

“…On transvaginal sonography at 28 to 33 weeks, the best cervical length cutoff for the identification of women at high risk for emergency cesarean delivery is 31 mm or less (16 times higher risk of preterm cesarean delivery with 83.3% sensitivity and 76.6% sensitivity) . Using a similar cervical length cutoff, others authors found that women presenting with placenta previa with a cervical length of 30 mm or less in 3 studies and 25 mm or less in 2 studies had higher rates of antepartum bleeding requiring emergency delivery. In our study, we found that the rate of cervical length shortening for the identification of women at high risk for emergency cesarean delivery was greater than 0.7 mm/wk (with 86.7% sensitivity, 53.8% specificity, 68.4% positive predictive value, and 77.8% negative predictive value).…”