Er. Guzman et al., A NEW METHOD USING VAGINAL ULTRASOUND AND TRANSFUNDAL PRESSURE TO EVALUATE THE ASYMPTOMATIC INCOMPETENT CERVIX, Obstetrics and gynecology, 83(2), 1994, pp. 248-252
Objective: To evaluate the ability of ultrasound with transfundal pres
sure to detect the incompetent cervix in pregnant women at risk for th
is condition. Methods: One hundred fifty pregnant women with no prior
pregnancy losses were scanned transabdominally, and 31 asymptomatic pr
egnant women with a prior history of cervical incompetency or risk for
this condition were scanned transvaginally. The control patients were
scanned once between 16-24 weeks, and the patients at risk were studi
ed 73 times between 8-25 weeks. After evaluating the cervix and its in
ternal os, transfundal pressure was applied. Cervical cerclages were p
laced for cervical funneling and shortening in response to transfundal
pressure or for a grossly incompetent cervix on ultrasound evaluation
. Results: Transfundal pressure elicited no changes in the internal ce
rvical os of the 150 control patients, of whom 141 delivered at term,
two miscarried at 22 and 23 weeks, and seven delivered prematurely (4.
7%). Fourteen of the 31 pregnancies at risk for cervical incompetency
revealed opening of the internal os or descent of the fetal membranes
with transfundal pressure. Thirteen of these 14 pregnancies were treat
ed with cerclage, with nine (64%) proceeding to term, three (21%) deli
vering prematurely, and two (14%) aborting. The one patient who did no
t receive a cerclage also aborted. In six cases, the cervix and its in
ternal os appeared normal but the membranes protruded into the endocer
vical canal in response to transfundal pressure. Conclusion: Applicati
on of transfundal pressure during transvaginal ultrasound evaluation o
f the cervix and its internal os may assist in detecting the asymptoma
tic incompetent cervix.