Labor Characteristics and Maternal-Infant Outcomes in Preterm Primiparous Women

NCT07844499 | Completed

• 1 other identifier: JDMCH-2026-036
• Study Type: observational
• Target: 436
• Locations: 1 country
• Sites: 1

Brief Summary

This retrospective observational study evaluates labor characteristics in primiparous women with spontaneous preterm birth at different gestational ages and examines their associations with maternal and neonatal outcomes. Medical records of women who delivered at Shanghai Jiading District Maternity and Child Health Care Hospital between January 1, 2020, and December 31, 2025, are reviewed. Participants are classified according to gestational age at delivery into very preterm (28 to 31+6 weeks), moderate preterm (32 to 33+6 weeks), and late preterm (34 to 36+6 weeks) groups. The study compares the onset and duration of the active phase of labor, cervical dilation rate, and durations of the first and second stages of labor across these gestational-age groups. The study also evaluates the associations between labor duration and maternal and neonatal outcomes, including postpartum blood loss, mode of vaginal delivery, and 5-minute Apgar score. The findings are intended to provide evidence for gestational age-specific and individualized labor management in women with spontaneous preterm birth.

Conditions

Preterm Birth

Keywords

Spontaneous Preterm Birth; Primiparous Women; Gestational Age; Labor Duration; Active Phase of Labor; Cervical Dilation; First Stage of Labor; Second Stage of Labor; Maternal Outcomes; Neonatal Outcomes; Epidural Analgesia; Postpartum Blood Loss; Apgar Score

Outcome Measures

Primary Outcomes (5)

• Duration of the Active Phase of Labor

  Duration of the active phase of labor, measured in hours, from the onset of the active phase to full cervical dilation (10 cm). The onset of the active phase was defined as the cervical dilation corresponding to the inflection point at which the cervical dilation curve changed from a gradual slope to its maximum slope.

  During labor, from the identified onset of the active phase to full cervical dilation (10 cm)

• Title Description Time Frame Cervical Dilation at the Onset of the Active Phase

  Cervical dilation, measured in centimeters, at the identified onset of the active phase of labor.

  At onset of the active phase during the index delivery

• Mean Cervical Dilation Rate During the Active Phase

  Mean cervical dilation rate, measured in cm/hour, calculated as (10 cm minus cervical dilation at the onset of the active phase) divided by the duration of the active phase.

  During labor, from the identified onset of the active phase to full cervical dilation (10 cm)

• Duration of the First Stage of Labor

  Duration of the first stage of labor, measured in hours, as documented in the obstetric medical record.

  During labor, from the documented onset of labor to full cervical dilation (10 cm)

• Duration of the Second Stage of Labor

  Duration of the second stage of labor, measured in hours, from full cervical dilation to delivery of the fetus.

  During labor, from full cervical dilation (10 cm) to fetal delivery

Secondary Outcomes (3)

• Postpartum Blood Loss Within 2 Hours After Delivery

  From fetal delivery through 2 hours postpartum

• Vaginal Delivery Status

  At the time of delivery

• 5-Minute Apgar Score

  5 minutes after birth

Study Arms (3)

Very Preterm Group

Primiparous women with spontaneous preterm birth who delivered vaginally at 28 weeks 0 days to 31 weeks 6 days of gestation. This group included 45 participants. No study-specific intervention was assigned; clinical and labor data were retrospectively obtained from existing medical records.

Other: Gestational Age at Delivery

Moderate Preterm Group

Primiparous women with spontaneous preterm birth who delivered vaginally at 32 weeks 0 days to 33 weeks 6 days of gestation. This group included 37 participants. No study-specific intervention was assigned; clinical and labor data were retrospectively obtained from existing medical records.

Other: Gestational Age at Delivery

Late Preterm Group

Primiparous women with spontaneous preterm birth who delivered vaginally at 34 weeks 0 days to 36 weeks 6 days of gestation. This group included 354 participants. No study-specific intervention was assigned; clinical and labor data were retrospectively obtained from existing medical records.

Other: Gestational Age at Delivery

Interventions

Gestational Age at Delivery OTHER

Gestational age at delivery was the primary exposure of interest. Participants were retrospectively classified into three groups according to gestational age at delivery: very preterm (28 weeks 0 days to 31 weeks 6 days), moderate preterm (32 weeks 0 days to 33 weeks 6 days), and late preterm (34 weeks 0 days to 36 weeks 6 days). No study-specific intervention was assigned, and all exposure and outcome information was obtained from existing medical records.

Late Preterm Group; Moderate Preterm Group; Very Preterm Group

Eligibility Criteria

• Age: 18 Years - 45 Years
• Sex: female
• Healthy Volunteers: No
• Age Groups: Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

Primiparous women with spontaneous preterm birth who delivered vaginally at Shanghai Jiading District Maternity and Child Health Care Hospital between January 1, 2020, and December 31, 2025, were identified retrospectively from the hospital electronic medical record system. Eligible women had a singleton pregnancy with vertex presentation and delivered between 28 weeks 0 days and 36 weeks 6 days of gestation. Participants were classified according to gestational age at delivery into very preterm, moderate preterm, and late preterm groups.

You may qualify if:

• Primiparous women undergoing vaginal delivery.
• Gestational age at delivery from 28 weeks 0 days to 36 weeks 6 days.
• Spontaneous preterm labor.
• Singleton pregnancy with vertex presentation.
• No labor interventions such as administration of uterotonic agents for labor augmentation or artificial rupture of membranes during labor.
• Complete clinical records.

You may not qualify if:

• Labor induction due to intrauterine fetal demise.
• Twin or multiple pregnancy.

Sponsors & Collaborators

• Maternal and Child Health Hospital, Jiading District: lead

Study Sites (1)

Maternal and Child Health Hospital, Jiading District

Shanghai, Shanghai Municipality, 201821, China

Location

MeSH Terms

Conditions

Premature Birth

Condition Hierarchy (Ancestors)

Obstetric Labor, Premature; Obstetric Labor Complications; Pregnancy Complications; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: RETROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: September 18, 2026
• First Posted: September 28, 2026
• Study Start: January 1, 2020
• Primary Completion: December 31, 2025
• Study Completion: December 31, 2025
• Last Updated: September 28, 2026

Record last verified: 2026-09

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL
• Time Frame: Data will be available beginning after publication of the primary study results and will remain available in accordance with the institution's data retention and governance policies.
• Access Criteria: Qualified researchers may request access to the de-identified individual participant data from the corresponding author for legitimate scientific research purposes. Requests will be reviewed on a case-by-case basis by the study investigators and, where required, the institution. Access will be subject to institutional approval and applicable privacy, confidentiality, and data protection requirements.

Locations

CN (1)