The Efficacy of Nifedipine in the Management of Preterm Labor

The Tocolytic Efficacy of Nifedipine in the Management of Threatened and Advanced Preterm Labor: A Study on 444 Singleton Pregnant Women With Intact Membranes

Preterm labor is one of the problems of obstetrics, and is one of the leading cause of neonatal morbidity and mortality. The incidence of preterm birth is around 7 to 9 %. The preterm baby is prone to respiratory, renal, neurologic and gastrointestinal problems. The correct diagnosis should be followed by the early administration of the most effective tocolytic agent with least side effects for both mother and fetus. Nifedipine, a calcium channel blocker, has gained a world-wide popularity recently since it has the least side-effects on both mother and fetus. In the present study, we aimed to evaluate the success rate of tocolytic agent 'nifedipine' on the spontaneous preterm labor of singeton pregnant women with intact amnionic membrane.

Preterm birth is the main reason of perinatal morbidity and mortality. The main management method of this important problem is to prolong the pregnancy period and to use corticosteroids to prevent fetal pulmonary distress. The most widely studied tocolytic agents, ritodrin, salbutamol and terbutaline are all betamimetics, and they are shown to prolong birth labor till 7 days and do not have any effct on the fetal mortality. However, their maternal side-effects are inevitable and can be mortal. They cause tachycardia, hypotension and some biochemical disturbances. Furthermore, maternal death is possible due to pulmonary edema. These adrenergic agonists are the first line tocolytics, but calcium canal blockers are becoming more popular since they have less side effects and comparable efficacy.

Calcium canal blockers are nonspecific smooth muscle relaxants used in adult hypertension treatment. Their tocolytic effect depends on their inhibition of calcium ions into the myometrial cells. In vitro studies have shown that they have strong relaxant effects on human myometrium. In the present study, our aim is to investigate the effects of nifedipine in our clinic in a period between 2002 and 2005, when it was first used in our clinic as the sıngle tocolytic agent. Its success in preventing preterm labor and its complications in our earlier practice will be noted and this retrospective study will guide us in its current usage, dosages and side-effects.

Inclusion Criteria:

• ingleton pregnant women with spontaneous preterm labor at their 23-37 weeks.

Exclusion Criteria:

• Normal pregnant women
• Pregnent women before 23 weeks of gestation
• Pregant women between 23 and 37 weeks of gestation, but with preterm early membrane rupture, chorioamnionitis, preterm labor without cervical change, multiple pregnancy, hypertension, intrauterine growth retardation, fetal anomaly, oligoanhidramniosis, placenta previa, decolman placentaand intrauterine fetal death