Study population
This retrospective cohort study assessed data from the obstetrics
department of Jiangsu Province Hospital from January
1st to December 31st, 2020. These
data included all maternal medical records and neonatal deliveries. The
inclusion criteria were a low-risk singleton pregnancy delivered at 40
0/7-41 6/7 weeks of gestation at our hospital. Low risk was defined as
the absence of any condition that might be a maternal or foetal
indication for delivery in a short time, such as any antepartum
hypertensive disorder, cardiac disease or renal
insufficiency9. Cases with electing caesarean
delivery, vaginal birth after caesarean section (VBAC) and partial data
loss were excluded. We divided pregnancies meeting the inclusion
criteria into a full-term group (40 0/7-40 6/7 weeks) and a late-term
group (41 0/7-41 6/7 weeks)10. This study was approved
by the Ethics Committee of Jiangsu Province Hospital [Ethics Committee
2020-SR-256].