Research hypothesis :

In pregnant women undergoing induction of labor, intramuscular injection of dexamethasone may accelerate induction delivery interval.

Research question :

In pregnant women undergoing induction of labor, does intramuscular injection of dexamethasone accelerate induction delivery interval ?

This study aims to assess the effect of intramuscular administration of dexamethasone on the induction delivery interval in full term patients undergoing induction of labor.

The use of corticosteroids is one of the methods put forward for the strengthening and speeding up the process of labor. After identification of glucocorticoid receptors in human amnion, the role of corticosteroids in starting the process of labor has been studied in numerous studies. Some of them discussed the relation between dexamethasone injection and labor induction but still there is insufficient data. So by the end of this study it may be possible to assess the effect of intramuscular dexamethasone injection on shortening the induction delivery interval.

• Type of Study: Randomized Clinical Double Blind Trial .
• Study Setting: The study will be conducted at Ain Shams Maternity Hospital.
• Study Population: Full term patients who attend to the labor ward in El Demerdash Maternity Hospital and scheduled for induction of labor.
• Sample Size: Sample size was calculated using PASS® version 15.0, setting the power (β) at 0.02 and the significance level (α) at 0.05. Data from previous reports (Kashanian et al., 2008) indicated that mean Induction-Active phase Interval in women receiving 8mg of dexamethasone before induction of labor and controls was 3.09±1.5 and 4.21±1.8 hours respectively. Calculation according to these values produced a minimal sample size of 70 patients to be randomized equally to both groups. Assuming a drop-out rate of 15%, a minimum drop-out inflated enrollment sample size of approximately 80 women will be needed.
• Ethical Considerations: The study will be approved from the Ethical Committee of the Department of Obstetrics and Gynecology, Faculty of Medicine, Ain Shams University. Informed written consent will be taken from all women before recruitment in the study, and after extensive explanation and clear discussion of risks and benefits.
• Study Procedures: A total of 80 women undergoing induction of labor will be included in this study after taking their consent for this clinical trial after full explanation of the trial.

Inclusion Criteria:

1. Primipara.
2. Gestational age (39-41) weeks according to Naegele's rule and a first-trimester ultrasound evaluation.
3. Vertex presentation.
4. Singleton fetus.
5. Intact fetal membranes.
6. No contraindication for vaginal delivery.
7. Cervix with a poor Bishop score (4-6).
8. Reactive CTG.
9. Average amount of liquor.

Exclusion Criteria:

1. Indication for cesarean section e.g. CPD, Placenta previa, IUGR, Non vertex presentation and previous cesarean section.
2. Maternal medical disorders as diabetes mellitus and severe pre-eclampsia.
3. Active phase of labor (cervical dilatation of 4 cm plus 3 forceful contractions over a ten minute span).
4. Preterm labor and premature rupture of membranes.
5. Multiparous women.
6. Significant vaginal bleeding. Placenta previa, probable placental abruption.
7. Fetal macrosomia>4.5 kg estimated by u/s.
8. Multiple pregnancy.
9. Fetal Distress and Non-reactive CTG.
10. Oligohydramnios.
11. IUGR.