BACKGROUND: Macrosomic fetuses are at increased risk of shoulder dystocia. We aimed to compare induction of labour with expectant management for large-for-date fetuses for prevention of shoulder dystocia and other neonatal and maternal morbidity associated with macrosomia.
METHODS: We did this pragmatic, randomised controlled trial between Oct 1, 2002, and Jan 1, 2009, in 19 tertiary-care centres in France, Switzerland, and Belgium. Women with singleton fetuses whose estimated weight exceeded the 95th percentile, were randomly assigned (1:1), via computer-generated permuted-block randomisation (block size of four to eight) to receive induction of labour within 3 days between 37(+0) weeks and 38(+6) weeks of gestation, or expectant management. Randomisation was stratified by centre. Participants and caregivers were not masked to group assignment. Our primary outcome was a composite of clinically significant shoulder dystocia, fracture of the clavicle, brachial plexus injury, intracranial haemorrhage, or death. We did analyses by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00190320.
FINDINGS: We randomly assigned 409 women to the induction group and 413 women to the expectant management group, of whom 407 women and 411 women, respectively, were included in the final analysis. Mean birthweight was 3831 g (SD 324) in the induction group and 4118 g (392) in the expectant group. Induction of labour significantly reduced the risk of shoulder dystocia or associated morbidity (n=8) compared with expectant management (n=25; relative risk [RR] 0·32, 95% CI 0·15-0·71; p=0·004). We recorded no brachial plexus injuries, intracranial haemorrhages, or perinatal deaths. The likelihood of spontaneous vaginal delivery was higher in women in the induction group than in those in the expectant management group (RR 1·14, 95% CI 1·01-1·29). Caesarean delivery and neonatal morbidity did not differ significantly between the groups.
INTERPRETATION: Induction of labour for suspected large-for-date fetuses is associated with a reduced risk of shoulder dystocia and associated morbidity compared with expectant management. Induction of labour does not increase the risk of caesarean delivery and improves the likelihood of spontaneous vaginal delivery. These benefits should be balanced with the effects of early-term induction of labour.
FUNDING: Assistance Publique-Hôpitaux de Paris and the University of Geneva.
<b>OBJECTIVE: </b>Macrosomia at term is associated with increased maternal and neonatal morbidity, including a higher rate of cesarean delivery and shoulder dystocia. Induction of labor has been suggested as a means to prevent further weight gain and improve outcome. The aim of this study was to determine whether or not induction of labor in these cases improves maternal and neonatal outcome.<b>METHODS: </b>Patients at term with an ultrasonic fetal weight estimation of 4000-4500 g were prospectively randomized into two groups: induction of labor (group D and expectant management (group II). Patients with diabetes, a previous cesarean delivery, or nonvertex presentation were excluded. Outcome variables included mode of delivery, arterial cord pH, presence of shoulder dystocia, brachial plexus injury, clavicular fracture, cephalohematoma, and intraventricular hemorrhage.<b>RESULTS: </b>Of 273 patients who were eligible for the study, 134 were randomized to group I and 139 to group II. Parity, gestational age, and fetal weight estimation were similar in the two groups. The neonates of group II patients were significantly heavier (4132.8 +/- 347.4 versus 4062.8 +/- 306.9 g; P = .024). The rate of cesarean delivery was 19.4% in group I and 21.6% in group II patients (not significant [NS]). Cord pH was similar in both groups. Shoulder dystocia was diagnosed in five group I and six group II patients (NS). None developed brachial plexus injury. There were two cases of mild, transient brachial plexus injury in group II patients without documented shoulder dystocia. Mild intraventricular hemorrhage was diagnosed in three of 44 group I and two of 31 group II neonates evaluated (NS).<b>CONCLUSION: </b>In this prospective, randomized study, induction of labor for suspected macrosomia at term did not decrease the rate of cesarean delivery or reduce neonatal morbidity. Ultrasonic estimation of fetal weight between 4000 and 4500 g should not be considered an indication for induction of labor.
Macrosomic fetuses are at increased risk of shoulder dystocia. We aimed to compare induction of labour with expectant management for large-for-date fetuses for prevention of shoulder dystocia and other neonatal and maternal morbidity associated with macrosomia.
METHODS:
We did this pragmatic, randomised controlled trial between Oct 1, 2002, and Jan 1, 2009, in 19 tertiary-care centres in France, Switzerland, and Belgium. Women with singleton fetuses whose estimated weight exceeded the 95th percentile, were randomly assigned (1:1), via computer-generated permuted-block randomisation (block size of four to eight) to receive induction of labour within 3 days between 37(+0) weeks and 38(+6) weeks of gestation, or expectant management. Randomisation was stratified by centre. Participants and caregivers were not masked to group assignment. Our primary outcome was a composite of clinically significant shoulder dystocia, fracture of the clavicle, brachial plexus injury, intracranial haemorrhage, or death. We did analyses by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00190320.
FINDINGS:
We randomly assigned 409 women to the induction group and 413 women to the expectant management group, of whom 407 women and 411 women, respectively, were included in the final analysis. Mean birthweight was 3831 g (SD 324) in the induction group and 4118 g (392) in the expectant group. Induction of labour significantly reduced the risk of shoulder dystocia or associated morbidity (n=8) compared with expectant management (n=25; relative risk [RR] 0·32, 95% CI 0·15-0·71; p=0·004). We recorded no brachial plexus injuries, intracranial haemorrhages, or perinatal deaths. The likelihood of spontaneous vaginal delivery was higher in women in the induction group than in those in the expectant management group (RR 1·14, 95% CI 1·01-1·29). Caesarean delivery and neonatal morbidity did not differ significantly between the groups.
INTERPRETATION:
Induction of labour for suspected large-for-date fetuses is associated with a reduced risk of shoulder dystocia and associated morbidity compared with expectant management. Induction of labour does not increase the risk of caesarean delivery and improves the likelihood of spontaneous vaginal delivery. These benefits should be balanced with the effects of early-term induction of labour.
FUNDING:
Assistance Publique-Hôpitaux de Paris and the University of Geneva.
