Threatened Preterm Labour: Vaginal Progesterone Versus Nifedipine

Preterm birth is defined as any birth before 37 completed weeks of gestation, or fewer than 259 days of gestation. It is estimated that annually, 13 million preterm infants are born. The worldwide rates of preterm birth vary with an estimated prevalence of 5-25%. Approximately 60% of preterm infants are born in south Asia and sub-Saharan Africa.

Progesterone and nifedipine were tested as tocolytic medications in women who were at risk of preterm birth to see whether they had any influence on efficacy, success, and the effects on the mother and foetus. Nifedipine is a drug which was reported for stopping uterine contractions in preterm labour. It is calcium channel blockers have some qualities that make them a better choice as compared to others. They decrease calcium entry through cell membranes, so controlling muscle contractility in various tissues like uterus. However; its use for maintenance tocolysis has yielded conflicting results.

Various interventions have been attempted to reduce the risk of preterm birth in women at increased risk, including progesterone, cervical cerclage, and cervical pessary. Progesterone plays a role in the maintenance of pregnancy by suppression of the calcium-calmodulin-myosin light chain kinase system. Additionally, progesterone has recognized anti-inflammatory properties, raising a possible link between inflammatory processes, alterations in progesterone receptor expression and the onset of preterm labor.