Do serial measurements of cervical length improve the prediction of preterm birth in asymptomatic women with twin gestations?

Abstract

Objective To determine whether serial measurements of cervical length can improve the prediction of preterm birth in asymptomatic women with twin gestations compared with a single measurement of cervical length at mid-gestation. Materials and Methods This was a retrospective cohort study of women with twin pregnancies followed in a tertiary medical center between 2012 and 2014. All participants underwent routine measurement of cervical length at mid-gestation and every 2–3 weeks thereafter until 28–32 weeks. For each patient, cervical length was determined at the following time periods: 18+0 to 21+6 weeks (Period 1, routine exam), 22+0 to 24+6 weeks (Period 2), 25+0 to 27+6 weeks (Period 3) and 28+0 to 32+0 weeks (Period 4). Measurements of cervical length at Periods 2–4 were analyzed in the form of either absolute length (in mm) or percent shortening relative to cervical length at Period 1. The performance of a stepwise algorithm that incorporates serial measurements of cervical length for the prediction of preterm birth was compared to that achieved with a single measurement of cervical length at Period 1. Results Overall 441 women with twin pregnancies who were eligible for the study underwent a total of 2,374 cervical length measurements. The association of a short cervix (<10th percentile) with preterm birth at <32 weeks persisted in each of the four periods of gestation [Odds ratio (95%-confidence interval): 7.2 (3.1–16.5), 15.3 (6.4–36.7), 10.3 (4.4–24.3) and 23.1(8.3–64.1), respectively]. Compared with a single measurement of cervical length at mid-gestation (Period 1), a stepwise algorithm integrating serial cervical length measurements from all four successive gestational age periods resulted in a significant increase in the area under the ROC curve (0.917 vs. 0.613, p<0.001). Similarly, when a target false positive rate of 5% was used, the same stepwise algorithm was associated with a higher detection rate (69% vs. 28%, p<0.001), higher positive likelihood ratio (14.54 vs. 5.12) and a lower negative likelihood ratio (0.32 vs. 0.76) for preterm birth at <32 weeks compared with a single measurement of cervical length at Period 1. Conclusions Integration of serial measurements of cervical length using a stepwise algorithm in asymptomatic women with twin gestations can improve the detection of women at risk of preterm birth. Prospective studies are needed to validate these findings, and to investigate whether improved risk assessment performance is sufficient to offset the additional costs associated with serial cervical length measurements.

Prenatal diagnosis and management of vasa previa in twin pregnancies: a case series and systematic review

“…3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 15 15 Twin pregnancies are at higher risks of preterm delivery and a recent retrospective cohort study of 441 women with twin pregnancies has found that integration of serial measurements of CL using a stepwise algorithm in asymptomatic women with twin gestations can improve the detection of women at risk of preterm birth. 46 Women with VP in a MC twin pregnancy also require a regular follow-up to assess the risks of TTTS and thus determining the twin chorionicity is pivotal in the management of these high-risk pregnancies.…”

The cytokine network in women with an asymptomatic short cervix and the risk of preterm delivery

“…1–15 The earlier the diagnosis of a short cervix, the more likely the patient will deliver preterm. 16–33 Compelling evidence supports the view that this condition is syndromic in nature and has multiple etiologies, 13,34–37 such as a decline in progesterone action, 38–48 prior cervical surgery, 49–57 intra-amniotic inflammation and/ or infection, 58–63 and genuine cervical insufficiency. 35,64 Patients with a mid-trimester sonographic short cervix can be offered treatment with vaginal progesterone 65–73 and, for those with a history of preterm birth, a cervical cerclage 74–80 may be placed.…”

Follow-Up of Asymptomatic High-Risk Patients with Normal Cervical Length to Predict Recurrence of Preterm Birth

“…At present, there are some promising reports about the utility of CL measurement in other high-risk women, such as those with multiple pregnancies [22, 30], although conflicting results have been reported in symptomatic patients [26, 31, 32]. Recently, Conde-Agudelo and Romero [25] conducted a systematic review and meta-analysis and concluded that overall, the change in CL over time has a low predictive accuracy for preterm birth before 35 and 37 weeks in women with singleton gestations, irrespective of the basal risk status of the patient.…”