Secondary maternal outcomes by planned mode of birth.

a<p>Values adjusted for maternal SES, BMI, and indication for previous caesarean birth.</p>b<p>Death or serious maternal outcome includes: one or more of maternal death; uterine rupture (defined as a clinically significant rupture involving the full thickness of the uterine wall and requiring surgical repair); severe haemorrhage (blood loss of ≥1,500 ml and/or requiring blood transfusion); hysterectomy for any complications resulting from birth; vulval or perineal haematoma requiring evacuation; deep vein thrombosis (DVT) or thrombophlebitis requiring anticoagulant therapy; pulmonary embolus (PE) requiring anticoagulant therapy; pneumonia due to infection, aspiration or other causes; adult respiratory distress syndrome; wound infection (requiring prolongation of hospital stay or readmission) or wound dehiscence; damage to the bladder, ureter, or bowel requiring repair, or cervical laceration extending to the lower uterine segment, or abnormal extension of the uterine incision; occurrence of a fistula involving the genital tract; bowel obstruction or paralytic ileus; pulmonary oedema; stroke (defined as acute neurological deficit >24 h); cardiac arrest; respiratory arrest.</p

Baseline maternal characteristics.

a<p>Ethnicity as reported by the participant.</p>b<p>Socioeconomic index as measured by SEIFA where high index scores indicate increasing levels of social disadvantage.</p><p>EPDS, Edinburgh Postnatal Depression Scale <a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.1001192#pmed.1001192-Cox1" target="_blank">[32]</a>; SD, standard deviation; SE, socioeconomic; STAI, Spielberger State-Trait Anxiety Inventory <a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.1001192#pmed.1001192-Marteau1" target="_blank">[33]</a>; SF3, SF36-Health Survey Questionnaire <a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.1001192#pmed.1001192-Ware1" target="_blank">[34]</a>.</p

Primary outcomes.

a<p>Values adjusted for maternal SES, BMI, and indication for previous caesarean birth.</p>b<p>Death or serious outcome includes: death (any fetal death after study entry or death of a liveborn infant prior to hospital discharge [excluding lethal congenital anomalies]); or serious neonatal morbidity (defined as one or more of: birth trauma [subdural or intracerebral haemorrhage, spinal cord injury, basal skull fracture, other fracture, peripheral nerve injury present at discharge from hospital]; seizures at <24 h age or requiring two or more drugs to control; Apgar score <4 at 5 min; cord pH<7·0; cord blood base deficit ≥12 mmol/l; neonatal encephalopathy stage 3; admission to NICU>4 d; severe neonatal lung disease [defined as MAP>10 and or FiO₂>0·80 with need for ventilation]; proven necrotising enterocolitis; or proven systemic infection in first 48 h of life treated with antibiotics).</p><p>NICU, neonatal intensive care unit.</p

Labour and birth outcomes.

a<p>Values adjusted for maternal SES, BMI, and indication for previous caesarean birth.</p><p>RCT, randomised controlled trial.</p

Secondary maternal outcomes by study group, including those related to preterm birth, psychological health, side effects of study treatment, and compliance.

<p>Secondary maternal outcomes by study group, including those related to preterm birth, psychological health, side effects of study treatment, and compliance.</p

Comparability of randomised study groups at trial entry and use of study treatment.

<p>Comparability of randomised study groups at trial entry and use of study treatment.</p

Consolidated Standards of Reporting Trials (CONSORT) flow diagram of participants in the study.

<p>Consolidated Standards of Reporting Trials (CONSORT) flow diagram of participants in the study.</p

Primary and secondary neonatal outcomes by study group.

<p>Primary and secondary neonatal outcomes by study group.</p

Treatment effects by subgroups according to the time from the start of treatment until birth.

<p>Treatment effects by subgroups according to the time from the start of treatment until birth.</p

Treatment effects by the individual reasons why the pregnancy was considered to be high risk.

<p>Treatment effects by the individual reasons why the pregnancy was considered to be high risk.</p