Expectant management until spontaneous labor or induction at 41 weeks.

Cesarean delivery performed immediately or shortly after clinical decision due to imminent threat to the life of the mother or fetus

Cesarean performed within approximately 30 minutes due to immediate life-threatening conditions (e.g., uterine rupture, severe fetal distress)

Cesarean performed within 60-75 minutes due to urgent but not immediately life-threatening indications (e.g., progressive fetal distress, labor arrest)

Planned cesarean performed at or after 39 weeks in the absence of emergency conditions, meeting all of the following:

1. Surgery scheduled ≥24 hours before onset of labor;
2. No spontaneous contractions or rupture of membranes;
3. Clear medical indications (e.g., placenta previa, breech presentation) or maternal request.

The rate of vaginal deliveries assisted with instruments such as forceps or vacuum.

Expressed in weeks and decimal days (e.g., 39 weeks + 5 days = 39.7 weeks)

Incidence of chorioamnionitis, defined as a clinical diagnosis before delivery as: maternal body temperature rises (>38°C) with 2 or more of the following symptoms:

1. Maternal tachycardia (>100 beats/min);
2. Fetal tachycardia (>160 beats/min)
3. Uterine tenderness and irritability
4. Purulent or malodorous amniotic fluid or vaginal discharge
5. Maternal leukocytosis (white blood cell count > 15000/mm3)

The incidence of third-or fourth-degree perineal laceration

Refer to the ARRIVE cohort, defined as any of the following situations:

1. Transfusion
2. Non-elective hysterectomy
3. Use of two or more uterotonics other than oxytocin
4. Other surgical interventions such as uterine compression sutures, uterine artery ligation, embolization and hypogastric ligation, balloon tamponade
5. Curettage

Refer to the ARRIVE cohort, defined as any of the following situations:

1. Clinical diagnosis of endometritis
2. Wound reopened for hematoma, seroma, infection or other reasons
3. Cellulitis requiring antibiotics
4. Pneumonia
5. Pyelonephritis
6. Bacteremia unknown source
7. Septic pelvic thrombosis

The proportion of admission to the ICU

The incidence of maternal death

The incidence of preeclampsia or gestational hypertension diagnosed during labor

Deep vein thrombosis or pulmonary embolism

Median patient-reported pain outcomes with a 10-point Likert scale

The mean birth weight

The proportion of female offspring in terms of physiological gender

Birth weight > 4000g

According to the infant's gender and gestational age, the birth weight exceeds the 90th percentile of infants of the same gestational age

According to the infant's gender and gestational age, the birth weight is less than the 10th percentile of infants of the same gestational age

Apgar score at 5 minutes after birth

The incidence of neonatal acidosis defined as umbilical artery blood pH < 7.10

The incidence of shoulder dystocia

The incidence of hyperbilirubinemia requiring phototherapy or exchange transfusion

The incidence of neonatal transfusion of blood products or blood

The incidence of hypoglycemia (blood glucose < 35mg/L) requiring intravenous treatment

The incidence of admission to the NICU lasting more than 48 hours

Infant weight, length, head circumference, chest circumference, sitting height, upper arm circumference, subcutaneous fat, height-chest circumference index, crown-rump length/length

Weight-for-length, length-for-age, weight-for-age z scores of infants, calculated using the World Health Organization (WHO) tool, WHO Anthro Survey Analyser

Height standard deviation for age < mean-2S or percentile method < P3

The proportion of abnormal results in neurological examinations (hearing development, nerve reflexes)

Total score, cognitive scale score, language scale score, motor scale score, social-emotional scale score, adaptive behavior scale score

Total score, communication domain score, gross motor domain score, fine motor domain score, problem-solving domain score, personal-social domain score

Allergic diseases diagnosed by neonatologists, including cow's milk allergy, allergic rhinitis, eczema/allergic dermatitis, asthma, wheezing and other allergic disorders

Median time from randomization to birth of the fetus, measured in hours

Rate of epidural analgesia use

Median maternal hospital stays, measured in hours

Median neonatal hospital stays, measured in hours

Total hospitalization cost during delivery, before insurance reimbursement

Out-of-pocket cost incurred during delivery hospitalization

Assessment of non-targeted metabolomic macroscopic differences and core metabolomic differences (including tryptophan, fatty acids) in cord blood plasma

Analysis of the proteomic characteristics of cord blood whole blood to trace back the health status during the fetal period