Tocolysis in Prevention of Preterm Labor

Preterm birth is defined as birth before 37 completed weeks of gestation .it occurs in 11.1%of birth globally affecting an estimated 14.9 million babies every year . It is generally accepted that approximately 65%-70%of preterm births are spontaneous,40%-45% of them due to spontaneous preterm labor and 25%-30%following preterm rupture of membranes.preterm birth represents the single largest cause of morbidity and mortality for newborn and is estimated for 29%of deaths in the first four weeks of life and also is estimated for of major cause of morbidity for pregnant women . Tocolytic agents include a wide range of drugs that can slow or suppress uterine contractions . Tocolytic are considered advantages in spontaneous preterm labor to : (a) allow time for the fetus to mature ,potentially avoiding deleterious effects of pre-maturity . (b)allow time for antenatal corticosteroids to be administered and have clinical effect. (c) allow time for intrauterine transfer to higher-care center where neonatal intensive care facilities are available . the ideal Tocolytic agent should be effective , easy to administer , without significant material ,fetal or neonatal side effects and permit time for antenatal corticosteroids to be administered and take effect . a variety of Tocolytic treatments have been used to inhibit uterine activity in women in spontaneous preterm labor , including betamimetics , calcium channel blockers , magnesium sulfate , prostaglandin inhibitors and oxytocin receptor antagonists however there is considerable global variation in types , doses and regimens of tocolytic agents uses to manage preterm labor . A comparison study between Ritodrine, magnesium sulfate and Nifedipine in terms of effect and morbidity will be conducted.