Preterm birth continues to be a major problem for our patients and for our society. Although the preterm birth rate in the United States fell for a fourth consecutive year in 2010, it remains alarmingly high. The incidence of preterm birth was almost 12% in 2009, according to the Centers for Disease Control and Prevention. It has been estimated, moreover, that two-thirds of preterm births in the United States are spontaneous.
Tocolysis can delay preterm birth by up to 48 hours and improve neonatal outcomes by allowing time for administration of corticosteroids. In general, however, tertiary prevention has been ineffective in decreasing the number of preterm births, and our attention has shifted to primary and secondary prevention. Several risk factors – from body mass index to various infections – have been studied, but their sensitivity or positive predictive value has been disappointing. However, two of these factors – a history of prior preterm birth and short cervical length – have proved to be important independent predictors of preterm delivery.
The value of careful history taking and prophylactic intervention for women with a prior preterm birth was recognized and approved by medical organizations and widely implemented in practice.
Treatment with vaginal progesterone also was associated in singletons with significant reductions in the rate of preterm birth at less than 35 weeks’ and less than 28 weeks’ gestation, the incidence of RDS, composite neonatal morbidity and mortality, birth weight, and NICU admission.
For optimal care of pregnant women, we have instituted universal transvaginal cervical length screening of all women with singleton gestation at the time of their anatomy scan. If cervical length is 5-20 mm, vaginal progesterone is offered; if the woman had a prior preterm delivery, the choice of cervical cerclage is also offered. If the cervical length is 21-25 mm, transvaginal ultrasound is repeated in 1-2 weeks.
Source: Ob.Gyn.News at http://www.obgynnews.com/views/master-class/blogview-enewsletter/cervical-length-screening-to-reduce-preterm-birth/d61c0785188d50b2f9a188814fa949e5.html?tx_ttnews%5BsViewPointer%5D=4