Vaginal fetal fibronectin evaluation before and immediately after ultrasonographic vaginal cervical length measurements in symptomatic women at risk of preterm birth: a pilot study.
OBJECTIVE
To determine if vaginal ultrasound for cervical length measurement induces the release of vaginal fetal fibronectin (fFN), leading to a false-positive fFN test.


METHODS
Participants included women with singleton pregnancies at 24-34 weeks' gestation who presented with uterine contractions without bleeding or membrane rupture. Women who had had intercourse or underwent pelvic examination less than 24 h previously were excluded. The first fFN test was followed immediately by vaginal ultrasonography with a transvaginal probe (three images per patient) and, thereafter, a second fFN test.


RESULTS
The first fFN test was positive in three patients, and in all, the second, post-ultrasound, fFN test was also positive. In all women with a negative baseline fFN test (n = 25), the second, post-ultrasound, fFN test was also negative.


CONCLUSIONS
Vaginal ultrasound examination does not artificially change the fFN status. This is in contrast to common understanding and may permit the performance of ultrasound examination before fFN, which can be restricted to cases of short cervix.
Ben-Haroush
Avi
A
Department of Obstetrics & Gynecology, Helen Schneider Hospital for Women, Rabin Medical Center, Beilinson Hospital, Petah Tikva, Israel. yudavi@inter.net.il
Poran
Eran
E
Yogev
Yariv
Y
Glezerman
Marek
M
D054791:Cervical Length Measurement / Q000009:adverse effects*; D005189:False Positive Reactions; D005260:Female; D005353:Fibronectins / Q000378:metabolism*; D006801:Humans; D010865:Pilot Projects; D011247:Pregnancy; D047928:Premature Birth; D014621:Vagina / Q000000981:diagnostic imaging / Q000378:metabolism*
C403421:FFN protein, human; D005353:Fibronectins