Ultrasonographic assessment of cervical length in triplet pregnancies

Our goal was to evaluate the utility of ultrasonographic assessment of cervical length in the management of triplet pregnancies and to compare these measurements with previously reported data for singleton pregnancies.

The maternal records for all triplet pregnancies managed at the Mayo Medical Center from January 1993-January 1998 were reviewed. Cervical length assessment was undertaken at regular intervals during each pregnancy according to an established real-time transperineal ultrasonographic technique. Presence or absence of cervical funneling was noted at the time of the examination. Obstetric management and outcome data were assessed.

Thirty-two triplet pregnancies were managed at our institution between January 1993 and January 1998. Average duration of pregnancy (+/-SD) was 32.4 +/- 2.3 weeks. Progressive cervical shortening was noted with advancing gestational age; average cervical lengths (+/-SD) were 42.0 +/- 5.0 mm at 10 weeks, 37.0 +/- 8.0 mm at 20 weeks, 26.0 +/- 10.0 mm at 25 weeks, and 21.0 +/- 7.0 mm at 30 weeks. Comparison of triplet cervical length measurements with reported data from singleton pregnancies revealed a significant difference between the singleton and triplet data, respectively, at both 24 weeks (35.2 +/- 8.3 mm vs 25.0 +/- 8.0 mm, P <.001) and 28 weeks (33.7 +/- 8.5 mm vs 28.0 +/- 11.0 mm, P <.005). Cervical funneling was noted in 3 women with an average of 27 days from onset to delivery.

Ultrasonographic assessment of cervical length is a useful adjuvant in the management of the triplet gestation. Triplet cervical length measurements are significantly different from those reported for gestational age-matched singleton pregnancies. Premature cervical shortening and the presence of cervical funneling are harbingers of premature delivery and should necessitate obstetric intervention.