WASHINGTON – Universal cervical length screening to prevent preterm birth has been implemented by more two-thirds of institutions with maternal-fetal medicine fellowship programs, but less than half of these programs screen with transvaginal ultrasound, a national survey has found.
The survey of 78 accredited programs also revealed geographic variations in the use of routine screening and the ultrasound approach employed, Dr. Adeeb Khalifeh reported at the annual meeting of the American College of Obstetricians and Gynecologists.
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All 78 programs responded to the survey. Fifty-three programs (68%) indicated they had implemented a universal screening program, defined as cervical length screening of women with singleton gestations who had not had a prior spontaneous preterm delivery. Of these, 28 use transabdominal ultrasound (TAU) and 25 use transvaginal ultrasound (TVU) for screening.
While the survey shows that a majority of academic institutions now perform universal cervical length screening, it also reveals that “almost one-third do not,” despite strong evidence of an inverse relationship between cervical length and risk of spontaneous preterm birth, said Dr. Khalifeh, a maternal-fetal medicine fellow at Thomas Jefferson University Hospital in Philadelphia who conducted the survey in 2015 with other physicians there.
Both ACOG and the Society for Maternal-Fetal Medicine recommend transvaginal measurements of cervical length for physicians who decide to implement universal cervical length screening.
ACOG’s 2012 Practice Bulletin on Prediction and Prevention of Preterm Birth, which does not mandate universal screening but supports its consideration, notes that, “if second trimester transabdominal scanning of the lower uterine segment suggests that the cervix may be short or have some other abnormality, it is recommended that a subsequent transvaginal ultrasound examination be performed to better visualize the cervix and establish its length” (Obstet Gynecol. 2012 Oct;120:964-73).
Cervical length assessment performed with TAU is unreliable, and it is less cost effective then assessment using TVU, Dr. Khalifeh said.
Vaginal progesterone as a treatment for short cervix in patients with singleton gestations was assessed and proven to be valuable in studies using TVU, not TAU, he noted.
Institutions in the Midwest had the highest rate of universal screening (94%) and the highest use of TVU (58% of programs with routine screening), while programs in the South had the lowest rate of university screening (58%) and the lowest use of TVU (12.5%).
In the Northeast, universal screening was reported by 60% of institutions, and the use of TVU by 40%. Among institutions in the West, 69% reported performing universal screening, with 40% of these programs using TVU.
Obstetrical volume did not impact the implementation of, or approach to, universal cervical length screening; there were no significant differences between institutions with a higher obstetrical volume (more than 3,000 deliveries annually) and a lower volume.
It’s “hard to extrapolate the practice of academic centers [to the community at large], so the findings might not be representative of what’s happening nationwide,” Dr. Khalifeh said.
He reported that he and his coinvestigators had no relevant financial disclosures.