<qa>  What is the presence of major fetal anomaly, intrauterine fetal death- The presence of major fetal anomaly, intrauterine fetal death, advanced cervical dilatation 4cm, membranes bulging into the vagina in asymptomatic women, history of ruptured membranes, major antepartum hemorrhage, major chronic medical disorder such as chronic hypertension, chronic renal disease, and pre-gestational diabetes mellitus as these conditions would increase the risk of PTL and potentially confound the primary study outcome, twins or higher order multiple pregnancy, any other condition in which continuation of the pregnancy can harm the mother or fetus and any contraindication for nifedipin andor nicorandil therapy. 