A universal mid-trimester transvaginal cervical length screening program and its associated reduced preterm birth...

Area of Science:

• Obstetrics and Gynecology
• Maternal-Fetal Medicine
• Public Health Screening

Background:

• Mid-trimester transvaginal cervical length assessment identifies women at risk for preterm birth.
• The low incidence of short cervix raises questions about the benefit of universal screening in women without prior preterm birth.

Purpose of the Study:

• To evaluate if a universal transvaginal cervical length screening program reduces the rate of preterm birth.

Main Methods:

• A cohort study compared preterm birth rates before and after implementing universal screening (July 2011) in women with singleton gestations and no prior preterm births.
• Included women undergoing obstetric sonograms between 18-24 weeks gestation from January 2007 to January 2014.
• Multivariable analysis and Breslow-Day test for homogeneity were used.

Main Results:

• The universal cervical length screening program was associated with a significant decrease in preterm birth rates (<37 weeks: 6.7% vs 6.0%; <34 weeks: 1.9% vs 1.7%; <32 weeks: 1.1% vs 1.0%).
• The reduction was primarily in spontaneous preterm births.
• The effect was similar in nulliparous and multiparous women with previous term births.

Conclusions:

• Universal transvaginal cervical length screening in women without a history of preterm birth is linked to a lower frequency of preterm birth.