Labour induction with an intermediate-dose oxytocin regimen has advantages over a high-dose regimen.
A total of 200 women planned for labour induction were randomised to receive high-dose oxytocin (6 mU/min with similar increments every 45 min) or intermediate-dose oxytocin (3 mU/min with similar increments every 45 min). Oxytocin solution was prepared with 30 units in 500 ml saline with which the infusion rate in ml/h is numerically equal to oxytocin in mU/min. We observed that the caesarean rate (18% vs 6%, p = 0.009), contraction abnormalities (35% vs 14%, p = 0.0005) and neonatal bilirubin levels (7.99 ± 2.70 vs 6.80 ± 2.65, p = 0.002) were higher with high-dose than with intermediate-dose. The induction-delivery interval (IDI) was similar (10 h 13 min with high-dose and 11 h 5 min with intermediate-dose; p = 0.237, NS). Nulliparous women benefited more with intermediate-dose as the caesarean rate was higher with high-dose (24.6% vs 7.9%, p = 0.011). Although the caesarean rate was higher in multiparous women with high-dose oxytocin, it was statistically not significant (5.7% vs 2.7%; p = 0.609). Oxytocin regimens for labour induction are usually high-dose (4-6 mU/min) or low-dose (1-1.5 mU/min). The former is associated with more contraction abnormalities and the latter with prolonged IDI; both result in an increased caesarean rate. In order to offset these disadvantages, an intermediate- dose regimen was selected. The increment interval of 45 min was selected in accordance with the pharmacokinetics of oxytocin. We observed a lower caesarean rate when compared with the high-dose regimen, without any increase in the IDI. Hence, we propose that the intermediate-dose oxytocin regimen should be preferred to the high-dose regimen for labour induction.
Department of Obstetrics and Gynaecology, Post Graduate Institute of Medical Education and Research , Chandigarh , India.
B G
BG
Manjula
R
R
Bagga
J
J
Kalra
S
S
Dutta
D000328:Adult; D002585:Cesarean Section / Q000379:methods / Q000706:statistics & numerical data; D004305:Dose-Response Relationship, Drug; D016903:Drug Monitoring / Q000379:methods; D005260:Female; D006801:Humans; D007751:Labor, Induced / Q000009:adverse effects / Q000379:methods; D010120:Oxytocics / Q000008:administration & dosage / Q000493:pharmacokinetics; D010121:Oxytocin / Q000008:administration & dosage / Q000493:pharmacokinetics; D011247:Pregnancy; D011256:Pregnancy Outcome; D016896:Treatment Outcome; D014590:Uterine Contraction / Q000187:drug effects*
D010120:Oxytocics; D010121:Oxytocin
Induction; intermediate-dose; labour; oxytocin