Is Nifedipine as a Tocolytic Effective in Facilitating In Utero Transfer?

Previous studies have reported that air medical transfer of women in preterm labor can be safely accomplished, without preterm birth occurring; in fact, many women were later discharged without preterm birth occurring. The purpose of this study was to determine if nifedipine, when used as a tocolytic, is effective at facilitating in utero transfer of women in preterm labor in the Top End of the Northern Territory of Australia.

This was a retrospective descriptive study over a 3-year period of all women transported in preterm labor between 23 + 6 to 36 + 6 weeks' gestation of pregnancy (N = 325).

The average gestation period was 32 + 2 weeks. The mean retrieval time was 6 hours. The mean time of birth from referral was 33 hours. A number of women gave birth to a preterm newborn in a remote health center (17%). There were 3 in-flight preterm births, and 49% of women were discharged without a preterm birth occurring. All women transported by air medical retrieval were admitted to the tertiary hospital for at least 24 hours.

In this study, nifedipine was used successfully to facilitate in utero transfer in many cases. Nearly half of the women referred were discharged without preterm birth occurring. Findings compare favorably with other published studies.