Hi. Thanks for asking in Healthcare Magic. Babies born before 37 weeks are called premature or preterm babies. Lung maturity occurs only around 37 weeks and so to improve the survival of the baby, premature labor is prevented or controlled. Many conditions can cause premature labor. Oligo or poly hydramnios (less or more amniotic fluid), cervical bleeding during pregnancy (threatened abortion), cervical incompetance or abnormal positions of placenta can all result in preterm labor. One of the drugs used to control the uterine contractions is Isoxsuprine (Duvadilan). It relaxes the uterus. It should not be used if membranes have already ruptured. No satisfactory drug is available for postponing the labor. Although incidences of increase in fetal blood sugar level and changes in lung have been reported with the use of Isoxsuprine during labor, it is one of the main drug used to postpone the labor as the survival of the baby depends upon the lung maturity and the delivery therefore needs to be postponed. I hope this is useful to you.