Department of Obstetrics and Gynaecology, Department of Biomedical and Clinical Sciences, University Hospital, Linköping University, Linköping, Sweden.
Department of Obstetrics and Gynaecology, Department of Biomedical and Clinical Sciences, University Hospital, Linköping University, Linköping, Sweden
BMJ Open. 2021 Mar 26;11(3):e044754. doi: 10.1136/bmjopen-2020-044754.
To evaluate oxytocin use for augmentation of labour in relation to body mass index (BMI) on admission to the labour ward, focusing on cumulative oxytocin dose and maximum rate of oxytocin infusion during the first stage of labour.
Prospective observational study.
Seven hospitals in Sweden.
1097 nulliparous women with singleton cephalic presentation pregnancy, ≥37 weeks of gestation, spontaneous onset of labour and treatment with oxytocin infusion for labour augmentation. The study population was classified into three BMI subgroups on admission to the labour ward: normal weight (18.5-24.9), overweight (25.0-29.9) and obese (≥30.0). The cumulative oxytocin dose was measured from the start of oxytocin infusion until the neonate was born.
Cumulative oxytocin dose.
Maximum rate of oxytocin infusion during the active phase of first stage of labour.
The mean cumulative oxytocin dose increased in the BMI groups (normal weight 2278 mU, overweight 3108 mU and obese 4082 mU (p<0.0001)). However, when adjusted for the confounders (cervical dilatation when oxytocin infusion was started, fetal birth weight, epidural analgesia), the significant difference was no longer seen. The maximum oxytocin infusion rate during the first stage of labour differed significantly in the BMI groups when adjusted for the confounding factors individually but not when adjusted for all three factors simultaneously. In addition, the maximum oxytocin infusion rate was significantly higher in women with emergency caesarean section compared with women with vaginal delivery.
Women with increasing BMI with augmentation of labour received a higher cumulative oxytocin dose and had a higher maximum oxytocin infusion rate during first stage of labour, however, when adjusted for relevant confounders, the difference was no longer seen. In the future, the guidelines for augmentation of labour with oxytocin infusion might be reconsidered and include modifications related to BMI.
评估入院时体重指数（BMI）与催产素在分娩中的应用关系，重点关注第一产程中的催产素累积剂量和最大催产素输注率。
前瞻性观察性研究。
瑞典 7 家医院。
1097 名初产妇，单胎头位妊娠，孕周≥37 周，自发性临产，接受催产素点滴引产。研究人群按入院时的 BMI 分为 3 个亚组：正常体重（18.5-24.9）、超重（25.0-29.9）和肥胖（≥30.0）。从催产素点滴开始到新生儿出生时测量催产素累积剂量。
催产素累积剂量。
第一产程活跃期的最大催产素输注率。
BMI 组的催产素累积剂量呈上升趋势（正常体重组 2278 mU，超重组 3108 mU，肥胖组 4082 mU（p<0.0001））。然而，调整混杂因素（催产素点滴开始时的宫颈扩张程度、胎儿出生体重、硬膜外镇痛）后，差异不再显著。单独调整混杂因素时，BMI 组间第一产程活跃期的最大催产素输注率差异有统计学意义，但同时调整所有 3 个因素时差异无统计学意义。此外，与阴道分娩相比，急诊剖宫产的产妇最大催产素输注率显著更高。
随着 BMI 的增加，催产素引产的产妇接受了更高的催产素累积剂量和更高的第一产程最大催产素输注率，然而，当调整相关混杂因素后，差异不再显著。未来，可能需要重新考虑和修改包括 BMI 相关因素的催产素引产指南。
