Prophylactic Cerclage of No Benefit With Multiples

OB/GYN News, June 15, 2001 by Kathryn Demott

CHICACO -- Women with multiple gestations or a history of midtrimester pregnancy loss do not benefit from prophylactic cervical cerclage and may even be harmed by it.

Instead, in both high-risk scenarios expectant management is advised, according to findings reported in two poster presentations at the annual meeting of the American College of Obstetricians and Gynecologists.

In the first study, records from 384 women with a history of midtrimester pregnancy loss were retrospectively reviewed to compare outcomes among 238 women who were managed with serial ultrasound and transfundal pressure between 15 and 24 weeks' gestation and 146 women who received elective cerclage, said the study's lead author, Dr. Edwin Guzman.

Among the women who were followed expectantly, 84 (35.3%) required rescue cerclage because of cervical shortening, said Dr. Guzman of St. Peter's University Hospital, New Brunswick, NJ.

Overall, women managed by serial sonography did much better than those in the elective cerclage group.

Interestingly, outcomes were nearly identical among women who ended up with a rescue cerclage and those in the elective cerclage group. Therefore waiting for sonographic cervical shortening as your indication for cerclage placement does not result in an increase in pregnancy loss or spontaneous prematurity compared with elective placement, he said in an interview.

About 80% of the patients who were followed with serial sonography and did not have cerclage gave birth at or after 37 weeks' gestation, compared with 60% of those who received elective cerclage and 64% who underwent sonography and required rescue cerclage.

There were significantly more deliveries at or after 37 weeks' gestation in the women who were followed with serial sonography versus those who were treated with elective cerclage (74.4% vs. 59.6%).

The pregnancy loss rate (delivery before 24 weeks) was 1.3% for patients in the ultrasound group who did not undergo cerclage, compared with 8.9% and 8.3% among women who received elective and rescue cerclages, respectively

All elective cerclages were placed on the assumption that these woman had an anatomic weakness of the cervix. There were no indications that these women were at additional risk compared with the rest of the cohort.

"Serial cervical sonographic surveillance with rescue cerclage for cervical lengths at or less than 2.0 cm between 15 and 24 weeks' gestation avoided the cerclage procedure in 65% of cases," Dr. Guzman and colleagues concluded.

"It's our belief that women with a prior midtrimester pregnancy loss can be followed by ultrasound and have a cerclage placed when it's necessary based on the onset, rate, and degree of cervical shortening," he added in an interview.

In addition, the study findings bolster an expectant management protocol outlined in an earlier randomized, controlled trial (Am. J. Obstet. Gynecol. 183[4]:823-29, 2000).

Under the protocol of Dr. Guzman's study, no action was taken as long as cervical length was at least 3 cm. Between 2.6 and 3 cm, ultrasound was repeated every 2-3 weeks; between 2.1 and 2.5 cm, exams were repeated every 1-2 weeks. Patients with cervical lengths between 1.5 and 2 cm on their first exam had repeat exams. Rescue cerclage was warranted when cervical length dipped below 1.5 cm. Physical activities were restricted when cervical length shortened to less than 2.5 cm.

In the second study presented at the meeting, which investigated the prevalence of cervical incompetence in women with multiple gestations, 802 women pregnant with multiples were followed through delivery.

Of the total, 29 women (3.6%) had cerclages placed, 12 for elective or prophylactic reasons and 17 for urgent or emergency causes, explained the study's lead author Dr. Barbara V. Parilla of Evanston (Ill.) Northwestern Healthcare.

Overall, women in the cerclage group gave birth significantly earlier compared with those in the no-cerclage group (29 vs. 34 weeks' gestation). Those women who underwent urgent or emergency cerclages had pregnancies that lasted an average of 21 weeks. The overall rate of delivery before 26 weeks' gestation was 41% in the elective cerclage group and 7% in the nocerclage group.

There were 10 pregnancy losses in the no-cerclage group that appeared consistent with a diagnosis of incompetent cervix; when taken together with the 29 women in the cerclage group presumed to have an incompetent cervix, the overall rate of cervical incompetence in the study was 4.9%.

"The relatively low incidence of cervical incompetence in our multiple gestations does not justify prophylactic cervical cerclage placement. Expectant management with serial cervical examinations starting at 16-18 weeks' gestation appears more prudent," Dr. Parilla concluded.