Preterm BirthNCT07844499
Labor Characteristics and Maternal-Infant Outcomes in Preterm Primiparous Women
An observational study of Preterm Birth, run by Maternal and Child Health Hospital, Jiading District at 1 site in China.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 to 45 years, women only
- Conditions the study is for
- Preterm Birth
- What is being tested?
- Gestational Age at Delivery
- How many people
- 436 participants
- Where
- 1 siteChina
- Study dates
- 1 Jan 2020to 31 Dec 2025
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 45 years
- Women only
- No healthy volunteers
- Adult
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.
Who may be able to join
- 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.
Who cannot join
- Labor induction due to intrauterine fetal demise.
- Twin or multiple pregnancy.
Trial locations and contacts
1 site in 1 country.
China1 site
Maternal and Child Health Hospital, Jiading District
Shanghai, Shanghai Municipality, 201821
About this study
Official title: Labor Characteristics of Primiparous Women With Spontaneous Preterm Birth at Different Gestational Ages and Their Association With Maternal and Infant Outcomes
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.
Read the detailed description
This is a single-center, retrospective observational study based on electronic medical records from Shanghai Jiading District Maternity and Child Health Care Hospital. The study population consists of primiparous women with spontaneous preterm birth at 28 to 36+6 weeks of gestation who delivered vaginally between January 1, 2020, and December 31, 2025.
Participants are categorized into three gestational-age groups: very preterm (28 to 31+6 weeks), moderate preterm (32 to 33+6 weeks), and late preterm (34 to 36+6 weeks). Labor characteristics assessed include cervical dilation at the onset of the active phase, duration of the active phase, mean cervical dilation rate during the active phase, duration of the first stage of labor, and duration of the second stage of labor. The study also evaluates differences in labor duration according to the use of epidural labor analgesia.
Maternal and neonatal variables collected from the medical records include maternal age, gravidity, pre-pregnancy body mass index, gestational age at delivery, pregnancy-related complications and comorbidities, neonatal birth weight, vaginal delivery status, postpartum blood loss within 2 hours after delivery, postpartum hemoglobin level, and 5-minute Apgar score.
Associations between the durations of the first and second stages of labor and maternal or neonatal outcomes are evaluated using regression analyses with adjustment for relevant potential confounding variables. Linear regression is used to assess postpartum blood loss, multinomial logistic regression is used to evaluate vaginal delivery outcomes, and binary logistic regression is used to evaluate neonatal Apgar outcomes. Restricted cubic spline analyses are used to explore potential dose-response relationships between labor duration and outcomes showing statistically significant associations.
The study is non-interventional. All information is obtained retrospectively from existing medical records and is analyzed after de-identification.
- Conditions
- Preterm Birth
- Being tested
- Gestational Age at Delivery
- 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
- Medical subject headings
- Premature Birth
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Gestational Age at DeliveryOther
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.
| Study group | Role | What they receive |
|---|---|---|
| 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. Receives: 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. Receives: 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. Receives: Other: Gestational Age at Delivery |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: During labor, from full cervical dilation (10 cm) to fetal delivery
Secondary outcomes (3)
Postpartum Blood Loss Within 2 Hours After Delivery
Postpartum blood loss within 2 hours after delivery, measured in milliliters using the gravimetric weighing method and documented in the medical record.
Measured: From fetal delivery through 2 hours postpartum
Vaginal Delivery Status
Vaginal delivery status categorized as spontaneous vaginal delivery, episiotomy, or forceps-assisted vaginal delivery, as documented in the medical record.
Measured: At the time of delivery
5-Minute Apgar Score
Neonatal Apgar score assessed 5 minutes after birth and documented in the medical record. The score was evaluated to assess neonatal condition after delivery.
Measured: 5 minutes after birth
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Sep 2026
- Study start1 Jan 2020
- Primary completion31 Dec 2025
- Study completion31 Dec 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Preterm BirthStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Retrospective
- Enrolment
- 436 participants (actual)
Sponsor and investigators
- Lead sponsor
- Maternal and Child Health Hospital, Jiading District
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Li Wu, Maternal and Child Health Hospital, Jiading District
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07844499
- Sponsor's protocol ID
- JDMCH-2026-036
- Status last verified
- Sep 2026
- First submitted
- 18 Sep 2026
- Last updated
- 28 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: De-identified individual participant data underlying the reported study results may be shared with qualified researchers upon reasonable request to the corresponding author. The shared data may include relevant maternal characteristics, gestational age at delivery, labor characteristics, maternal outcomes, and neonatal outcomes. No directly identifiable participant information will be provided. Data sharing will be subject to institutional approval and applicable privacy and data protection requirements.
Study at a glance
From the registry record, last updated by the sponsor on 28 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Labor Characteristics of Primiparous Women With Spontaneous Preterm Birth at Different Gestational Ages and Their Association With Maternal and Infant Outcomes
- ClinicalTrials.gov ID
- NCT07844499
- Acronym / sponsor ID
- JDMCH-2026-036
- 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
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 436 participants (actual)
- Lead sponsor
- Maternal and Child Health Hospital, Jiading DistrictUniversity, hospital or other
- Study start
- 1 Jan 2020 (actual)
- Primary completion
- 31 Dec 2025 (actual)
- Study completion
- 31 Dec 2025 (actual)
- First posted
- 28 Sep 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
This is a single-center, retrospective observational study based on electronic medical records from Shanghai Jiading District Maternity and Child Health Care Hospital. The study population consists of primiparous women with spontaneous preterm birth at 28 to 36+6 weeks of gestation who delivered vaginally between January 1, 2020, and December 31, 2025.
Participants are categorized into three gestational-age groups: very preterm (28 to 31+6 weeks), moderate preterm (32 to 33+6 weeks), and late preterm (34 to 36+6 weeks). Labor characteristics assessed include cervical dilation at the onset of the active phase, duration of the active phase, mean cervical dilation rate during the active phase, duration of the first stage of labor, and duration of the second stage of labor. The study also evaluates differences in labor duration according to the use of epidural labor analgesia.
Maternal and neonatal variables collected from the medical records include maternal age, gravidity, pre-pregnancy body mass index, gestational age at delivery, pregnancy-related complications and comorbidities, neonatal birth weight, vaginal delivery status, postpartum blood loss within 2 hours after delivery, postpartum hemoglobin level, and 5-minute Apgar score.
Associations between the durations of the first and second stages of labor and maternal or neonatal outcomes are evaluated using regression analyses with adjustment for relevant potential confounding variables. Linear regression is used to assess postpartum blood loss, multinomial logistic regression is used to evaluate vaginal delivery outcomes, and binary logistic regression is used to evaluate neonatal Apgar outcomes. Restricted cubic spline analyses are used to explore potential dose-response relationships between labor duration and outcomes showing statistically significant associations.
The study is non-interventional. All information is obtained retrospectively from existing medical records and is analyzed after de-identification.
Study design
- Observational model
- Cohort
- Time perspective
- Retrospective
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Very Preterm Group | – | Other: Gestational Age at DeliveryPrimiparous 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. |
| Moderate Preterm Group | – | Other: Gestational Age at DeliveryPrimiparous 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. |
| Late Preterm Group | – | Other: Gestational Age at DeliveryPrimiparous 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. |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult
- 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.
Key inclusion criteria (6 listed)
- 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.
Key exclusion criteria (2 listed)
- Labor induction due to intrauterine fetal demise.
- Twin or multiple pregnancy.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Gestational Age at DeliveryGestational 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. | Other | Late Preterm Group, Moderate Preterm Group, Very Preterm Group |
Primary outcome
Duration of the Active Phase of Labor
Time frame: During labor, from the identified onset of the active phase to full cervical dilation (10 cm)
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.
Title Description Time Frame Cervical Dilation at the Onset of the Active Phase
Time frame: At onset of the active phase during the index delivery
Cervical dilation, measured in centimeters, at the identified onset of the active phase of labor.
Mean Cervical Dilation Rate During the Active Phase
Time frame: During labor, from the identified onset of the active phase to full cervical dilation (10 cm)
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.
Duration of the First Stage of Labor
Time frame: During labor, from the documented onset of labor to full cervical dilation (10 cm)
Duration of the first stage of labor, measured in hours, as documented in the obstetric medical record.
Duration of the Second Stage of Labor
Time frame: During labor, from full cervical dilation (10 cm) to fetal delivery
Duration of the second stage of labor, measured in hours, from full cervical dilation to delivery of the fetus.
3 secondary outcomes
Postpartum Blood Loss Within 2 Hours After Delivery
Time frame: From fetal delivery through 2 hours postpartum
Vaginal Delivery Status
Time frame: At the time of delivery
5-Minute Apgar Score
Time frame: 5 minutes after birth
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 Sep 2026.
- Individual participant dataSharing planned: Yes. De-identified individual participant data underlying the reported study results may be shared with qualified researchers upon reasonable request to the corresponding author. The shared data may include relevant maternal characteristics, gestational age at delivery, labor characteristics, maternal outcomes, and neonatal outcomes. No directly identifiable participant information will be provided. Data sharing will be subject to institutional approval and applicable privacy and data protection requirements.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Preterm Birth, run by Maternal and Child Health Hospital, Jiading District at 1 site in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 28 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Duration of the Active Phase of Labor (time frame: During labor, from the identified onset of the active phase to full cervical dilation (10 cm)). The study lists 5 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Sep 2026.