[Ultrasonography on the labour ward]

Ultrasonography is one of the most important technologies introduced in obstetrics over the last 30 years. Its use on labour ward has changed the obstetrical practice. Literature describing its applications is large. Therefore, the objective of this article is to present a review of the literature on the potential interest of ultrasonographic use on labour ward. Transvaginal ultrasonography, in the case of premature labour, has allowed an adaptation of the management. Use of ultrasonography instead of the Bishop score seems to be logical considering the superiority of its diagnostic value and the reduction of interindividual variability. Nevertheless its advantages must not be overestimated. Use of ultrasonography to check fetal presentation might be justified in case of clinical doubt, a systematic use being difficult in case of clinical certainty. On the other hand, it seems logical to use it routinely before an instrumental extraction. Transabdominal ultrasonography seems to be generally more accessible than transvaginal ultrasonography, which might be useful in case of fetal engagement. Ultrasonography on labour ward finds its indication in many cases: fetal heart recording difficulties or abnormalities, before induction, engagement diagnosis, multiple pregnancies, evaluation of the amniotic fluid index, fetal weight estimation, vaginal bleeding and unknown pregnancy. Thus, ultrasonography is more and more present on labour ward, and practitioners should use it as a complementary tool for investigation rather than a replacement for their clinical skills.