Relation of cervical length at 22-24 weeks of gestation to demographic characteristics and obstetric history

Abstract

Preterm delivery is the main cause of neonatal death and ultrasonographic cervical assessment has been shown to be more accurate than digital examination in recognizing a short cervix. This is a crosssectional study, involving 1131 women at 22-24 weeks of pregnancy, designed to determine the distribution of cervical length and to examine which variables of demographic characteristics and obstetric history increase the risk of a short cervix (15 mm or less). The distribution of maternal demographic and obstetric history characteristics among patients with cervical length ≤15 mm was analyzed and compared to the findings for the general population. Risk ratios (RR) between subgroups were generated from this comparison. Median cervical length was 37 mm and in 1.5% of cases it was 15 mm or less. The proportion of women with a short cervix (≤15 mm) was significantly higher among patients with a low body mass index (RR = 3.5) and in those with previous fetal losses between 16-23 weeks (RR = 33.1) or spontaneous preterm deliveries between 24-32 weeks (RR = 14.1). We suggest that transvaginal sonographic measurement of cervical length be performed as part of a routine midtrimester ultrasound evaluation. There are specific variables of demographic characteristics and obstetric history which increase the risk of detecting a short cervix at 22-24 weeks.

Transvaginal sonographic measurement of cervical length to predict preterm birth in asymptomatic women at increased risk: a systematic review

“…The remaining 29 studies were reviewed in detail 31,32,34 -60 . Fifteen studies were not included for the following reasons: four studies included low-risk women in their cohorts 37 -40 , three studies included multiple gestations 41 -43 , two studies did not present data for the outcome of interest (preterm birth) 44,45 , two studies did not present information in such a way as to allow abstraction of data into 2 × 2 tables 36,46 , one study presented data that had been previously published 47 , one study did not present data on cervical length and was a secondary analysis of an earlier published study 48 , one study used translabial ultrasound for some women 49 and one study was an editorial and so did not present new data 35 . The remaining 14 studies were included in the review.…”

Screening for Placental Insufficiency by Transvaginal Uterine Artery Doppler at 22–24 Weeks of Gestation

“…Using the transvaginal approach and color flow mapping it was possible to visualize both uterine arteries and obtain adequate waveforms in all patients examined. The use of the mean PI allowed for a simple and objective single screening tool, avoiding the subjectivity of criteria such as the presence or absence of notching in one or both uterine arteries as in other studies [9,14,18,21] .…”

“…Transvaginal sonography with a 5-MHz transducer (Aloka1700 II SSD, Aloka Co. Ltd., Tokyo, Japan) was carried out by one of two ultrasound specialists who had received the Fetal Medicine Foundation Certificate of Competence in Doppler. The probe was placed in the anterior fornix of the vagina for measurement of cervical length as previously described [18] . The probe was subsequently moved laterally and color Doppler was used to identify each uterine artery at the level of the internal os.…”

W123 Screening of Preterm Labor in Yazd Province: Transvaginal Ultrasound Assessment of the Cervix in the Second Trimester

“…They asserted that this factor can be beneficial in predicting preterm labor (22). Considering the positive relationship between short cervical length and increased rate of preterm labor incidence, measurement of cervical length can be suggested as an efficient way for predicting preterm labor (3, 4, 21, 23-25). …”