Preterm labour refers to a delivery that occurs between 20 weeks and before completing 37 weeks of gestation. It may or may not be preceded by preterm labor Preterm labor (PTL) is one of the leading causes of perinatal morbidity and mortality. It is one of the major public health problems, especially with reference to mortality, disability and health care expenses~The diagnosis of preterm labor based upon clinical criteria of regular painful uterine contractions occurs between 20 weeks and before 37 weeks gestation accompanied by cervical change (dilation and/or effacement). Vaginal bleeding and/or ruptured membranes in this setting increase diagnostic certainty , using the following specific criteria:~Uterine contractions (≥4 every 20 minutes or ≥8 in 60 minutes) Plus one of the following:-~Cervical dilation equal or more than 3 cm~Cervical length less than 20 mm on transvaginal ultrasound~Cervical length between 20 to less than 30 mm on transvaginal ultrasound and positive fetal fibronectin test . (This criterion will not be relied upon in this study because it is costly and widely not available in most laboratories)~Since uterine contractions are the most frequently recognized sign of preterm labor, inhibition of uterine contractions with tocolytic agents to prolong pregnancy and reduce neonatal complications has been and continues to be the focus of treatment of preterm labor~• Nifedipine, a calcium channel blocker, could be used as a first line tocolytic agent~Owing to this side effects of Nifedipine, another novel drug (Nicorandil) is studied and according to literature Nicorandil is as effective as Nifedipine for tocolysis in preterm labour~is an anti-angina medication that has the dual properties of a nitrate and ATP-sensitive K+ channel activator. Nicorandil has proved to be safe as anti angina treatement in pergnency
Nicorandil (potassium channel activator) is claimed to be as effective as Nifedipine (calcium channel blocker) for tocolysis in preterm labour~aim of the study: To assess the efficacy of Nicorandil compared with Nifedipine as a tocolytic agent in delaying labour for 48 hours following their administration