A randomized controlled double blinded study included 200 women with preterm contractions. After successful arrest of contractions women were randomized into 2 equal groups: GI women received nifedipine 20 mg tablets twice daily and GII women received Ritodrine 5 mg tablets every 6 hours. The primary outcome was gestational age at delivery and the secondary outcomes include episodes of recurrent preterm labor, mode of delivery, maternal side effects and neonatal outcome

Women included in the study were diagnosed as preterm labor defined according to American Academy of Pediatrics and the American College of Obstetricians and Gynecologists (2012) with regular contractions before 37 weeks that are associated with cervical change [12].

Regular uterine contractions means at least 4 in 20 minutes or 8 in 60 minutes) and cervical changes are either cervical dilation more than 1 cm, and/or cervical effacement ≥ 80%. Threatened preterm labour was defined as contractions without any appreciable cervical changes. Women included were between 18 and 40 years old at gestational age between 28 and 34 weeks. Women with failed tocolytic treatment to stop uterine contractions, those with established preterm labor (cervical dilatation ≥ 4 cm), with multifetal pregnancy, fetal anomalies or those with contraindication of continuation of pregnancy (antepartum hemorrhage, premature rupture of membranes, evidence of intrauterine infections or non reassuring fetal heart rate tracing) were excluded from the study.

During the pre-selection visit, exclusion and inclusion criteria were applied; with recording of full medical history, findings on abdominal ,local and ultrasound examination.

When the patient's consent was obtained, digital vaginal examination was done prior to start of medication Treatment of TPL was achieved through Indomethacin administered rectally. A dose of 50 to 100 mg is followed at 8-hour intervals not to exceed a total 24-hour dose of 200 mg for a maximum of 48 hours [4].

After successful arrest of contractions women were randomized using automated web based randomization system ensuring allocation concealment into 2 equal groups: GI women received nifedipine 20 mg tablets (Epilat Retard®, EIPICO, Egypt) twice daily, starting 12 hours after arrest of threatened preterm labor(The cost is 20 tab=5.20 LE) and GII women received Ritodrine 5 mg tablets (Yutopar®, PHARCO, Alexandria) every 6 hours, starting 12 hours after arrest of threatened preterm labor.(The cost is 20 tab=20LE Treatment was maintained till 37 weeks of gestation unless established preterm delivery commence

Inclusion Criteria:

• Women included in the study were diagnosed as preterm labor defined according to American Academy of Pediatrics and the American College of Obstetricians and Gynecologists (2012) with regular contractions before 37 weeks that are associated with cervical change .

Regular uterine contractions means at least 4 in 20 minutes or 8 in 60 minutes) and cervical changes are either cervical dilation more than 1 cm, and/or cervical effacement ≥ 80%. Threatened preterm labour was defined as contractions without any appreciable cervical changes. Women included were between 18 and 40 years old at gestational age between 28 and 34 weeks

Exclusion Criteria:

• Women with failed tocolytic treatment to stop uterine contractions,
• those with established preterm labor (cervical dilatation ≥ 4 cm),
• multifetal pregnancy
• fetal anomalies
• those with contraindication of continuation of pregnancy (antepartum hemorrhage, premature rupture of membranes, evidence of intrauterine infections or non reassuring fetal heart rate tracing)