Diagnostic ultrasound in labor and delivery.

Clinical questions often arise suddenly and at odd hours during the intrapartum period. Many questions can be answered immediately by making use of readily available diagnostic ultrasonography. The verification of fetal life, fetal number and fetal presentation, amniotic fluid assessment and determination of placental location are important in maternal-fetal care. Sonographic skills facilitate the performance of certain procedures, including external version of the breech fetus, intrapartum twin management and amniocentesis for lung-maturity testing or culture in cases of suspected chorioamnionitis. Sonography can be helpful in the evaluation of possible placental abruption, but management of this condition remains clinical and should not be affected by a negative sonographic scan.