Reduction in cervical length after vaginal progesterone in women with short cervix is significantly associated with preterm delivery at ≤ 34 weeks and < 37 weeks of gestation.

OBJECTIVE: To evaluate the association between changes in cervical length (CL) after vaginal progesterone treatment and preterm delivery (PTD). METHODS: This was a retrospective cohort study that included 197 singleton pregnancies without (n = 178) and with (n = 19) a history of PTD which were found to have a short cervix (≤ 25 mm) between 18 + 0 and 23 + 6 weeks' gestation with a follow-up transvaginal CL measurement taken at least 1 week after vaginal progesterone treatment started. Receiver-operating-characteristics (ROC)-curve analysis was performed and three CL shortening patterns were evaluated: (1) ≥ 10% reduction; (2) ≥ 20% reduction; and (3) ≥ 5 mm reduction relative to the first CL measurement. The predictive performance of each CL reduction cut-off and its association with PTD ≤ 34 weeks and PTD < 37 weeks were evaluated. RESULTS: Overall, the rate of PTD ≤ 34 weeks was 16.8% (33/197) and that of PTD < 37 weeks was 36.5% (72/197). The area under the ROC curve of cervical shortening expressed in % for predicting PTD ≤ 34 weeks and PTD < 37 weeks was 0.703 and 0.608, respectively. Cervical shortening was observed in 60/197 (30.5%) patients, with 49/60 (81.7%) women showing ≥ 10% reduction, 32/60 (53.3%) ≥ 20% reduction and 27/60 (45.0%) ≥ 5 mm reduction in CL. Sensitivity and specificity for PTD ≤ 34 weeks were, respectively, 48.5% and 79.9% for ≥ 10% reduction; 36.4% and 87.8% for ≥ 20% reduction; and 27.3% and 89.0% for ≥ 5 mm reduction in CL. For PTD < 37 weeks, sensitivity and specificity were, respectively, 36.1% and 81.6% for ≥ 10% reduction; 27.8% and 90.4% for ≥ 20% reduction; and 20.8% and 90.4% for ≥ 5 mm reduction in CL. The highest positive likelihood ratios for PTD ≤ 34 and < 37 weeks were for ≥ 20% CL reduction (2.98 (95% CI, 1.62-5.49) and 2.89 (95% CI, 1.52-5.57), respectively). Despite significant differences in sensitivity among the different cut-offs for cervical shortening, favoring the ≥ 10% reduction cut-off, a reduction of ≥ 20% in CL showed the strongest association with PTD ≤ 34 weeks (odds ratio (OR), 4.11 (95% CI, 1.75-9.62)) and < 37 weeks (OR, 3.62 (95% CI, 1.65-7.96)), as compared with a less pronounced reduction in CL. CONCLUSIONS: In women with a short cervix treated with vaginal progesterone, a reduction in CL on a subsequent ultrasound scan can predict PTD ≤ 34 and < 37 weeks. A ≥ 20% reduction in CL had the highest positive likelihood ratio and association with PTD ≤ 34 and < 37 weeks compared with ≥ 10% or ≥ 5 mm reduction. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Doppler evaluation of normal and abnormal placenta.

Doppler techniques are needed for the evaluation of the intraplacental circulation and can be of great value in the diagnosis of placental anomalies. Highly sensitive Doppler techniques can differentiate between the maternal (spiral arteries) and fetal (intraplacental branches of the umbilical artery) components of the placental circulation and assist in the evaluation of the placental functional units. A reduced number of placental functional units can be associated with obstetric complications, such as fetal growth restriction. Doppler techniques can also provide information on decidual vessels and blood movement. Abnormal decidual circulation increases the risk of placenta accreta. Doppler evaluation of the placenta greatly contributes to the diagnosis and clinical management of placenta accreta, vasa previa, placental infarcts, placental infarction hematoma, maternal floor infarction, massive perivillous fibrin deposition and placental tumors. However, it has a limited role in the diagnosis and clinical management of placental abruption, placental hematomas, placental mesenchymal dysplasia and mapping of placental anastomoses in monochorionic twin pregnancies. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.