Factors Associated With Success of Emergent
Second-Trimester Cerclage
Mary Faith C. Terkildsen, MD, Barbara V. Parilla, MD, Praveen Kumar, MD, and
William A. Grobman, MD, MBA
OBJECTIVE: To assess the factors associated with delivery
greater than or equal to 28 weeks’ gestation after placement
of an emergent cerclage in women with singleton gesta-
tions.
METHODS: All women who underwent emergent cerclage,
defined as any cerclage placed between 16 and 24
6
/7 weeks’
gestation in response to documented cervical change on
physical examination, at Northwestern Memorial Hospital
from 1980 to 2000 were identified. Univariable and multi-
variable analyses were used to determine the factors most
associated with achieving at least 28 weeks’ gestation.
RESULTS: One hundred sixteen women were eligible for
analysis. Maternal age, race, and operative variables such
as suture type and use of antibiotics were not associated
with differences in the frequency of delivery at or after 28
weeks. Cerclage placement at or after 22 weeks’ gestation
increased the likelihood of reaching 28 weeks, whereas
several cervical examination findings (dilatation greater
than 3 cm, cervical length less than 0.5 cm, and membranes
prolapsing beyond the external cervical os) as well as need
for placement in a nullipara significantly reduced the like-
lihood of reaching 28 weeks. In multivariable analysis,
nulliparity (odds ratio 0.31, 95% confidence interval 0.1,
0.8) and membranes prolapsing beyond the external cervi-
cal os (odds ratio 0.24, 95% confidence interval 0.1, 0.4)
continued to be associated with delivery before 28 weeks,
whereas cerclage placement at or after 22 weeks (odds ratio
3.2, 95% confidence interval 1.2, 8.6) increased the chance of
achieving at least 28 weeks’ gestation.
CONCLUSION: Nulliparity, the presence of membranes pro-
lapsing beyond the external cervical os, and gestational age
less than 22 weeks at cerclage placement are associated
with decreased chance of delivery at or after 28 weeks after
emergent cerclage; these factors may be used to help coun-
sel patients considering the procedure. (Obstet Gynecol
2003;101:565–9. © 2003 by The American College of Ob-
stetricians and Gynecologists.)
Painless cervical dilatation (also known as “cervical in-
competence”) leading to premature rupture of mem-
branes (PROM) and preterm delivery is implicated in
10 –25% of second-trimester pregnancy losses.
1,2
Pro-
phylactic cerclage placed early in the second trimester is
an accepted treatment in patients with a history of incom-
petent cervix in a prior pregnancy, with fetal salvage
rates reported as high as 75–90%.
3
The management of
cervical incompetence in the emergent setting, when
cervical change documented on physical examination
has already occurred, is more controversial. No random-
ized study has prospectively documented the benefits
that emergent cerclage placement imparts. Although one
prospective nonrandomized study has suggested that
increased gestational time can be gained by placement of
emergent cerclage, the benefits of this increased latency
remain unclear, as many children continue to be deliv-
ered at the threshold of viability, and thus suffer from the
resultant sequelae of extreme prematurity.
4,5
Indeed, little published evidence exists to assist in
counseling patients who present with cervical change
documented by physical examination in the second tri-
mester regarding the probability of a desirable outcome
after emergent cerclage placement. The present litera-
ture is predominantly limited to series with small num-
bers of patients and with a wide variation in entry
criteria. For example, some series have included diagno-
sis of cervical shortening or funneling by ultrasound as
an indication for emergent cerclage placement, rather
than strictly defining entry criteria by physical examina-
tion findings alone.
6
Along these lines, two randomized
trials have been performed to assess the benefits of
cerclage in response to cervical change, but only cervical
change diagnosed by routine ultrasonographic assess-
ment.
7,8
In fact, in these trials, women with significant
cervical change on physical examination, as evidenced
by membranes prolapsing beyond the external os, were
explicitly excluded. In the retrospective trials that have
included only women with cervical change diagnosed by
physical examination, a variety of surgical techniques
From the Sections of Maternal–Fetal Medicine and Pediatrics, Northwestern
University Medical School, Northwestern University, Chicago, Illinois.
565 VOL. 101, NO. 3, MARCH 2003 0029-7844/03/$30.00
© 2003 by The American College of Obstetricians and Gynecologists. Published by Elsevier. doi:10.1016/S0029-7844(02)03117-4