Preterm LaborPhase 4PAP-CNCT02511574
Comparison Between Natural Progesterone and Vaginal Pessary for the Prevention of Spontaneous Preterm Birth
A Phase 4 study testing natural progesterone and cervical pessary in people with Preterm Labor and Premature Birth, run by University of Sao Paulo at 1 site in Brazil.
Trial summary
The aim of this study is to compare the effectiveness between the cervical pessary and the natural progesterone in reduction of preterm birth rates in pregnant women with a uterine cervical length of 25 mm or less evaluated by transvaginal ultrasonography. Read more about this study
- Who is it for?
- Any age, women onlyHealthy volunteers can take part
- Conditions the study is for
- Preterm Labor, Premature Birth
- What is being tested?
- natural progesterone and cervical pessary
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 203 participants
- Where
- 1 siteBrazil
- Study dates
- 3 Aug 2015to 30 Aug 2023
- Phase
- Phase 4
- 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 Any age
- Women only
- Healthy volunteers accepted
- Child, Adult, Older adult
Who may be able to join
- gestational age between 20 weeks and 23 weeks and 6 days
- singleton pregnancies
Who cannot join
- fetal death at randomization
- major structural or chromosomal abnormality
- cervical cerclage in the current pregnancy
- preterm rupture of membranes diagnosed before randomization
Trial locations and contacts
1 site in 1 country.
Brazil1 site
Hospital das Clínicas da Faculdade de Medicina da USP
São Paulo, São Paulo, 05403-000
About this study
Official title: Comparison Between Natural Progesterone and Vaginal Pessary for the Prevention of Spontaneous Preterm Birth in Pregnant Women With a Uterine Cervix Measuring 25 mm or Less in Length
The aim of this study is to compare the effectiveness between the cervical pessary and the natural progesterone in reduction of preterm birth rates in pregnant women with a uterine cervical length of 25 mm or less evaluated by transvaginal ultrasonography.
Read the detailed description
Preterm birth is the leading cause of perinatal morbidity and mortality. The rates of spontaneous premature labor have not changed much during the past 10 years. A significant decrease in mortality and morbidity of premature babies will only be possible if women at risk of spontaneous preterm birth are accurately identified and administered preventive therapies. Ultrasonographic measurement of the cervix between 20 and 24 weeks of gestation can improve the identification of both women with single pregnancies and those with twin pregnancies at risk. Asymptomatic women with a short uterine cervix (25 mm or less) are at increased risk of spontaneous premature labor.
The prophylactic use of progesterone during the early phase of pregnancy in women with a history of preterm birth and those with a short cervix can prevent preterm birth.
The cervical pessary is a device used also for the prevention of preterm birth. Vaginal infections are also important causes of preterm birth. There are not many studies about the vaginal microbiome in pregnant women.
Measurement of cervical length is used as a screening test because it is inexpensive, has a short learning curve, and is well tolerated by patients. In addition, placement and removal of the pessary is an easy, accessible, and noninvasive procedure. The results on the concentration of omega 3 and preterm birth are still conflicting.
The aim of this study is to compare the effectiveness of the cervical pessary and the natural progesterone in reduction of preterm birth rates in pregnant women with a uterine cervix measuring 25 mm or less in length as evaluated by transvaginal ultrasonography, assess whether there is a relationship between maternal plasma concentration of omega 3 and preterm birth, and compare the microbiome in these women.
Methods: A prospective randomized controlled trial including pregnant women at the time of morphological ultrasound between 20 and 23 weeks and 6 days of pregnancy. Pregnant women in this gestational age with cervical length of 25 mm or less will be randomized between the conduct and the inclusion of progesterone vaginal pessary. In patients of both groups vaginal discharge sample will be collected at the time of randomization.
- Conditions
- Preterm Labor, Premature Birth
- Being tested
- natural progesterone, cervical pessary
- Keywords
- progesterone, uterine cervix, cervical pessary
- Medical subject headings
- Obstetric Labor, Premature, Premature Birth
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
natural progesteroneDrug
cervical pessaryDevice
| Study group | Role | What they receive |
|---|---|---|
| cervical pessary | Experimental | Patients with uterine cervical length ≤ 25 mm are randomized to use the cervical pessary or natural progesterone to compare their effectiveness in the reduction of preterm birth rates. Receives: Device: cervical pessary |
| natural progesterone | Active comparator | Patients with uterine cervical length ≤ 25 mm are randomized to use the cervical pessary or natural progesterone to compare their effectiveness in the reduction of preterm birth rates. Receives: Drug: natural progesterone |
What is being measured
The primary outcome is the main question the study is designed to answer.
Spontaneous preterm birth before 34 weeks of gestational age
All births that occurred before 34 weeks of gestation were included, excluding iatrogenic births (medically indicated).
Measured: before 34 weeks of gestation
Secondary outcomes (4)
Overall preterm birth before 37, 34, 32 and 30 weeks of gestational age
All births (spontaneous and iatrogenic) that occurred before 37, 34, 32 and 30 weeks of gestation were included.
Measured: before 37, 34, 32 and 30 weeks of gestation
Spontaneous preterm birth before 37, 32 and 30 weeks of gestational age
All births that occurred before 37, 32 and 30 weeks of gestation were
Measured: before 37, 32 and 30 weeks of gestation
Adverse neonatal events
Intraventricular hemorrhage, respiratory distress syndrome, retinopathy of prematurity and necrotizing enterocolitis
Measured: Neonatal period (up to 27 days after birth)
The need of neonatal special care
admission to neonatal intensive care unit [NICU], mechanical ventilation, phototherapy, treatment for sepsis and blood transfusion
Measured: Neonatal period (up to 27 days after birth)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Jul 2015 (estimated)
- Study start3 Aug 2015
- Primary completion10 Dec 2022
- Study completion30 Aug 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Preterm LaborStudies of the same condition, open and under way.
- More trials run by University of Sao PauloThe sponsor's other registered studies.
- 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
- Interventional
- Phase
- Phase 4
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 203 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Sao Paulo
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Mario Henrique Burlacchini de Carvalho, University of Sao Paulo
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02511574
- Sponsor's protocol ID
- 470.095
- Acronym
- PAP-C
- Status last verified
- Mar 2026
- First submitted
- 6 Jul 2015
- Last updated
- 19 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 19 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison Between Natural Progesterone and Vaginal Pessary for the Prevention of Spontaneous Preterm Birth in Pregnant Women With a Uterine Cervix Measuring 25 mm or Less in Length
- ClinicalTrials.gov ID
- NCT02511574
- Acronym / sponsor ID
- PAP-C / 470.095
- Conditions
- Preterm Labor, Premature Birth
- Keywords
- progesterone, uterine cervix, cervical pessary
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 203 participants (actual)
- Lead sponsor
- University of Sao PauloUniversity, hospital or other
- Study start
- 3 Aug 2015 (actual)
- Primary completion
- 10 Dec 2022 (actual)
- Study completion
- 30 Aug 2023 (actual)
- First posted
- 30 Jul 2015 (estimated)
- 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.
The aim of this study is to compare the effectiveness between the cervical pessary and the natural progesterone in reduction of preterm birth rates in pregnant women with a uterine cervical length of 25 mm or less evaluated by transvaginal ultrasonography.
Detailed description
Preterm birth is the leading cause of perinatal morbidity and mortality. The rates of spontaneous premature labor have not changed much during the past 10 years. A significant decrease in mortality and morbidity of premature babies will only be possible if women at risk of spontaneous preterm birth are accurately identified and administered preventive therapies. Ultrasonographic measurement of the cervix between 20 and 24 weeks of gestation can improve the identification of both women with single pregnancies and those with twin pregnancies at risk. Asymptomatic women with a short uterine cervix (25 mm or less) are at increased risk of spontaneous premature labor.
The prophylactic use of progesterone during the early phase of pregnancy in women with a history of preterm birth and those with a short cervix can prevent preterm birth.
The cervical pessary is a device used also for the prevention of preterm birth. Vaginal infections are also important causes of preterm birth. There are not many studies about the vaginal microbiome in pregnant women.
Measurement of cervical length is used as a screening test because it is inexpensive, has a short learning curve, and is well tolerated by patients. In addition, placement and removal of the pessary is an easy, accessible, and noninvasive procedure. The results on the concentration of omega 3 and preterm birth are still conflicting.
The aim of this study is to compare the effectiveness of the cervical pessary and the natural progesterone in reduction of preterm birth rates in pregnant women with a uterine cervix measuring 25 mm or less in length as evaluated by transvaginal ultrasonography, assess whether there is a relationship between maternal plasma concentration of omega 3 and preterm birth, and compare the microbiome in these women.
Methods: A prospective randomized controlled trial including pregnant women at the time of morphological ultrasound between 20 and 23 weeks and 6 days of pregnancy. Pregnant women in this gestational age with cervical length of 25 mm or less will be randomized between the conduct and the inclusion of progesterone vaginal pessary. In patients of both groups vaginal discharge sample will be collected at the time of randomization.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| cervical pessary | Experimental | Device: cervical pessaryPatients with uterine cervical length ≤ 25 mm are randomized to use the cervical pessary or natural progesterone to compare their effectiveness in the reduction of preterm birth rates. |
| natural progesterone | Active comparator | Drug: natural progesteronePatients with uterine cervical length ≤ 25 mm are randomized to use the cervical pessary or natural progesterone to compare their effectiveness in the reduction of preterm birth rates. |
Who may qualify
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (2 listed)
- gestational age between 20 weeks and 23 weeks and 6 days
- singleton pregnancies
Key exclusion criteria (4 listed)
- fetal death at randomization
- major structural or chromosomal abnormality
- cervical cerclage in the current pregnancy
- preterm rupture of membranes diagnosed before randomization
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 |
|---|---|---|
| natural progesterone | Drug | natural progesterone |
| cervical pessary | Device | cervical pessary |
Primary outcome
Spontaneous preterm birth before 34 weeks of gestational age
Time frame: before 34 weeks of gestation
All births that occurred before 34 weeks of gestation were included, excluding iatrogenic births (medically indicated).
4 secondary outcomes
Overall preterm birth before 37, 34, 32 and 30 weeks of gestational age
Time frame: before 37, 34, 32 and 30 weeks of gestation
Spontaneous preterm birth before 37, 32 and 30 weeks of gestational age
Time frame: before 37, 32 and 30 weeks of gestation
Adverse neonatal events
Time frame: Neonatal period (up to 27 days after birth)
The need of neonatal special care
Time frame: Neonatal period (up to 27 days 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 19 Mar 2026.
Related trials for Preterm Labor
Not yet recruiting
nCPAP-NAVA-Backup Versus Standard nCPAP for Severe Apnea in Preterm Infants ≤28 Weeks
Apnea of Prematurity
Recruiting
Study of the Influence of Intraperitoneal Insufflation of CO2 by Laparoscopy on the Short-term Evolution of Premature Infants With Ulcerative Necrotizing Enterocolitis
Preterm Birth, Enterocolitis, Necrotizing
RecruitingObservational study
Multidimensional Dynamic Early Warning System for Neonatal Necrotizing Enterocolitis: A Multicenter Clinical Study
NEC - Necrotizing Enterocolitis
Recruiting
Optimization of Saturation Targets And Resuscitation Trial (OptiSTART)
Premature Infants, Bronchopulmonary Dysplasia
RecruitingObservational study
Growing Little PEAPODS Study
Premature Birth, Premature Infant
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?
A Phase 4 study testing natural progesterone and cervical pessary in people with Preterm Labor and Premature Birth, run by University of Sao Paulo at 1 site in Brazil.
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 2 inclusion and 4 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 19 Mar 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 Brazil. 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.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
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?
Spontaneous preterm birth before 34 weeks of gestational age (time frame: before 34 weeks of gestation). 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 19 Mar 2026.