Fentanyl citrate is a potent short-acting narcotic reported to cause less nausea and sedation than morphine or meperidine hydrochloride. The purpose of this prospective investigation was to determine whether a safe but adequate intrapartum dosing schedule is possible. A total of 137 women with uncomplicated term pregnancies were offered a standard intravenous dose (50 mcg or 100 mcg hourly as needed) of fentanyl citrate during active labor. Temporary analgesia and mild sedation were apparent in each case. The cumulative dose varied in accordance with maternal needs (mean, 140 +/- 42 micrograms; range, 50 mcg to 600 micrograms). Apart from a brief decrease in fetal heart rate variability that lasted 30 minutes, no worrisome pattern was apparent from exposure to fentanyl citrate. Pediatric examinations were performed without knowledge of analgesic therapy on infants exposed to fentanyl citrate and those not exposed to analgesics. No differences were found in frequencies of newborn depressed respirations, low Apgar scores, or neurologic and adaptive capabilities at two hours and 24 hours postnatally. With the use of the described dosing schedule, fentanyl citrate was helpful during labor and did not cause immediate or prolonged hazards to the mother and unborn infant.