Parry S et al. – Optimal strategies to employ cervical ultrasound and progesterone treatment might be revealed by additional studies investigating cervical length cut–offs, frequency of screening, selective screening in higher–risk groups, and the use of transabdominal cervical length screening as a surrogate for transvaginal cervical length screening.
- Three large randomized controlled trials investigating the efficacy of universal cervical length screening and treatment with vaginal progesterone or cervical cerclage to prevent preterm delivery have been published over the past several years.
- None of these trials demonstrate proven efficacy for universal cervical length screening and cerclage placement in women with short cervical length.
- However, universal cervical length screening and treatment with daily vaginal progesterone in women with short cervical length reduces the risk of preterm birth, but large numbers of women must be screened to prevent a relatively small number of preterm deliveries.
- Issues that should be considered while implementing universal cervical length screening include: 1) the standards of quality and reproducibility for transvaginal ultrasound cervical length ascertainment; 2) the implications of screening on the application of therapeutic strategies to populations not known to benefit (so–called “indication creep”); and 3) the willingness of obstetricians to prescribe vaginal progesterone formulations that are not approved by the US Food and Drug Administration for preterm birth prevention.