To study the effect of antenatal
indomethacin or
nylidrin hydrochloride treatment on the fetal and neonatal ductus arteriosus and tricuspid valve function, 84 pregnant women with threatened
premature birth between 22.9 and 34.0 wk gestation and 94 of their offspring born at 24.7 to 41.6 wk of gestation were studied by Doppler echocardiography. Forty-six women were treated with
indomethacin and 38 with
nylidrin. Both peak systolic and peak diastolic velocities in the ductus increased after administration of
indomethacin and exceeded the corresponding velocities in the fetuses of the
nylidrin group (p = 0.0001). Ductal constriction occurred in 42 of 49 fetuses treated with
indomethacin (86%).
Tricuspid valve regurgitation (TR) was evident in 11 of 49 fetuses treated with
indomethacin (22%). The mean gestational age of the fetuses with TR (30.0 wk) tended to be higher than those without TR (28.3 wk, p = 0.056). In the
nylidrin group, no fetus had ductal constriction or TR. A significant increase in peak systolic velocity (r = 0.54, p = 0.0001) and in peak diastolic velocity (r = 0.46, p = 0.0001) in the ductus with advancing gestational age was demonstrated in the
indomethacin group; however, in the
nylidrin group, there was a less remarkable increase in peak systolic velocity (r = 0.35, p = 0.04) and no increase in peak diastolic velocity (r = 0.02, p = 0.93). In infants born at or before 35 wk gestation, incidences of both spontaneous closure and
indomethacin-induced closure of ductus were similar in both study groups (p > 0.1).(ABSTRACT TRUNCATED AT 250 WORDS)