A prospective, randomized trial of nifedipine vs. ritodrine in threatened preterm labor.
OBJECTIVE
To compare the tocolytic efficacy and maternal tolerance of nifedipine with ritodrine in the management of threatened preterm labor.


METHODS
Prospective randomized study of 52 singleton pregnancies with preterm labor between 26 and 34 week's gestation. The capacity to delay delivery 48 h, 7 days, until week 36 or until fetal weight reached 2500 g were the outcome variables assessed. Doppler ultrasound studies were performed on the fetal umbilical artery as control.


RESULTS
No significant differences were found in the delay of delivery, but significantly fewer maternal side-effects were found in the nifedipine group. Doppler ultrasound results were similar in both groups.


CONCLUSIONS
Nifedipine is a valid and well-tolerated alternative among the tocolytic drugs, and apparently does not significantly alter fetal vascular blood flow.
Department of Obstetrics and Gynecology, La Paz Hospital, Autonoma University, Madrid, Spain. jagarciav@meditex.es
J A
JA
García-Velasco
A
A
González González
D000033:Abortion, Threatened / Q000517:prevention & control; D000328:Adult; D001034:Apgar Score; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism; D005260:Female; D005333:Fetus / Q000098:blood supply; D005865:Gestational Age; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007231:Infant, Newborn; D007262:Infusions, Intravenous; D009543:Nifedipine / Q000008:administration & dosage*; D007752:Obstetric Labor, Premature / Q000517:prevention & control*; D011247:Pregnancy; D011256:Pregnancy Outcome; D011446:Prospective Studies; D012039:Regional Blood Flow; D012312:Ritodrine / Q000008:administration & dosage* / Q000009:adverse effects; D015149:Tocolytic Agents / Q000008:administration & dosage* / Q000009:adverse effects; D018617:Ultrasonography, Doppler, Pulsed; D016216:Ultrasonography, Prenatal; D014469:Umbilical Arteries / Q000000981:diagnostic imaging
D001786:Blood Glucose; D015149:Tocolytic Agents; D012312:Ritodrine; D009543:Nifedipine