The Outcome of preterm labour and preterm prelabour rupture of membranes after oral salbutamol or nifedipine SR

Abstract

RATIONALE: Preterm labour (PTL) and preterm prelabour rupture of membranes (FT - PLROM) are still a problem. Several tocolytics with varying doses have been tried in the treatment. OBJECTIVE: To compare the effectiveness and safety of oral salbutamol and nifedipine SR in the management of PTL and PT - PLROM. DESIGN AND SETTING: A randomised controlled trial from 15 May 2002 to 30 April 2003 at the University Obstetric Unit, Teaching Hospital, Galle. SUBJECTS AND METHOD: One hundred and fourteen consecutive women who presented with PT - PLROM or fulfilled the diagnostic criteria for PTL-more than one uterine contraction occurring within ten minutes and the cervix effaced and greater than 1cm, and without any contraindications for tocolysis, were randomly assigned to receive either oral salbutamol 4 mg 8 hourly or nifedipine SR 20 mg 12 hourly for 48 hours. The first author was unaware of the treatment regimen until the final analysis. Three doses of dexamethasone 8 mg 12 hourly were also given. MAIN OUTCOME MEASURES: The time interval upto delivery, birth weight of the baby, admissions to premature baby unit, perinatal deaths and adverse maternal effects were assessed. RESULTS: Forty-eight women received salbutamol and 66 received nifedipine SR. Between the two groups there were no significant differences in the basic characteristics, the mean period of gestation, the frequency of uterine contractions and the cervical dilatation in the subjects. Delivery occurred after a mean of 9.7 days SD 14.7 (salbutamol group) and 14.6 days SD 21.0 (nifedipine SR group) (P=0.2). In the salbutamol group 75% delivered within 9.5 days while in the Nifedipine SR group it took 28.0 days for 75% of the subjects to deliver. The mean birth weight of the babies in the nifedipine SR group (2.47 kg, SD 0.68) was significantly higher (P=0.04) than that of the babies in the salbutamol group (2.18 kg, SD 0.67). There were six perinatal deaths in the salbutamol group but only two deaths in the nifedipine SR group (P=0.06). Adverse effects were more common with salbutamol; tremors (54% versus 5%), palpitations was significantly higher (P=0.04) than that of the babies in the salbutamol group (2.18 kg, SD 0.67). There were six perinatal deaths in the salbutamol group but only two deaths in the nifedipine SR group (P=0.06). Adverse effects were more common with salbutamol; tremors (54% versus 5%), palpitations (46% versus 9%), nausea (10% versus 5%) compared to nifedipine SR. Headache was commoner with nifedipine SR (26% versus 10%). CONCLUSIONS: If oral to colytics are used in women with preterm labour or preterm prelabour rupture of membranes nifedipine SR is apparently better than salbutamol with regard to adverse maternal effects. There may be a delay in delivery and an increase of the birth weight of the baby with nifedipine SR treatment. (46% versus 9%), nausea (10% versus 5%) compared to nifedipine SR. Headache was commoner with nifedipine SR (26% versus 10%). CONCLUSIONS: If oral tocolytics are used in women with preterm labour or preterm prelabour rupture of membranes nifedipine SR is apparently better than salbutamol with regard to adverse maternal effects. There may be a delay in delivery and an increase of the birth weight of the baby with nifedipine SR treatment.