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NCT Number: NCT02511574

Comparison Between Natural Progesterone and Vaginal Pessary for the Prevention of Spontaneous Preterm Birth

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.

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Key information

Conditions

Preterm Labor Female Urogenital Diseases and Pregnancy Complications Obstetric Labor Complications Obstetric Labor, Premature Pregnancy Complications Premature Birth Urogenital Diseases

Sex eligibility

Female

Study type

Interventional

Phase

Phase 4

Primary location

Hospital das Clínicas da Faculdade de Medicina da USP

São Paulo, 05403-000, Brazil

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • gestational age between 20 weeks and 23 weeks and 6 days
  • singleton pregnancies

Exclusion criteria

  • fetal death at randomization
  • major structural or chromosomal abnormality
  • cervical cerclage in the current pregnancy
  • preterm rupture of membranes diagnosed before randomization

Treatment and study plan

natural progesterone

Drug

Cervical pessary

Device

Primary outcomes

  1. 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).

Secondary outcomes

  1. Overall preterm birth before 37, 34, 32 and 30 weeks of gestational age

    Time frame: before 37, 34, 32 and 30 weeks of gestation

    All births (spontaneous and iatrogenic) that occurred before 37, 34, 32 and 30 weeks of gestation were included.

  2. Spontaneous preterm birth before 37, 32 and 30 weeks of gestational age

    Time frame: before 37, 32 and 30 weeks of gestation

    All births that occurred before 37, 32 and 30 weeks of gestation were

  3. Adverse neonatal events

    Time frame: Neonatal period (up to 27 days after birth)

    Intraventricular hemorrhage, respiratory distress syndrome, retinopathy of prematurity and necrotizing enterocolitis

  4. The need of neonatal special care

    Time frame: Neonatal period (up to 27 days after birth)

    admission to neonatal intensive care unit [NICU], mechanical ventilation, phototherapy, treatment for sepsis and blood transfusion

Sponsors and collaborators

Lead sponsor

University of Sao Paulo

Other

Registry information

Official study 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

Acronym: PAP-C

Important dates

Study start
2015
Primary completion
2022
Study completion
2023
First posted
Jul 30, 2015
Registry last updated
Mar 19, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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