Microbiome in Preterm Birth

September 1, 2020 updated by: Alex Farr, MD PhD, Medical University of Vienna

The Human Microbiome in pPROM, Preterm Birth and the Neonatal Infant: a Prospective Longitudinal Pilot-study

The aims of this prospective longitudinal case-control pilot-study are (1) to characterize the changes of the vaginal, uterine and placental microbiome in pregnant women experiencing pPROM with immediate hospitalization and consecutive caesarean section at preterm, in comparison to uneventful term births with elective cesarean section, as well as (2) to evaluate the influence of the maternal on the neonatal microbiome and the early neonatal outcome in pPROM preterm cases, in comparison to uneventful term births.

The first aim will be achieved by collecting vaginal and rectal swabs for microbiome analysis in women experiencing pPROM, followed by uterine and placental swabs that are collected during the caesarean section. Control samples will be collected at the same time points from women undergoing elective caesarean section at term. The second aim will be achieved by microbiome analysis of rectal, oral/buccal, and skin swabs taken from newborns that are either born preterm after pPROM, or at term, both by caesarean section.

Study Overview

Status

Unknown

Conditions

Detailed Description

A total of 100 study participants will be included, assigned to one of the following groups:

Study group:

• This group will consist of 50 pregnant women, who experienced pPROM between 22+5 and 28+0 gestational weeks, either presenting at the primary study site, or being referred from other hospitals, and delivered at preterm by cesarean section.

Control group:

• This group will consist of 50 pregnant women, who are scheduled for elective cesarean section at the outpatient department of the primary study site, between a 32+0 and 37+0 gestational weeks, and delivered at term by cesarean section.

Recruitment:

Recruitment of all patients will take place at the Medical University of Vienna, Department of Obstetrics and Gynecology. Women in the study group will be referred from outside hospitals or will present for any reason at our department. Verification of pPROM will be performed by speculum examination and detection of amniotic fluid pooling. In case of unclear findings, an enzymatic test (e.g., Amnisure®, QUIAGEN Sciences, LLC; Germantown, MD 20874, USA) will be conducted. Following pPROM verification, women who meet the inclusion criteria will be offered to participate in the study. Those who experience a spontaneous vaginal delivery instead of a cesarean section due to any reason, will be considered as drop-out. Women in the control group will be recruited during their routine presentation for elective cesarean section (for any reason that does not meet the exclusion criteria of the study) that will be scheduled at term. Those who experience preterm birth although being scheduled for elective cesarean at term, will be considered as drop-out. During their consultation at the outpatient department, these women will be offered to participate in the study.

Sampling:

All swabs will be collected from sub-investigators of this study using a standardized procedure. For anonymization, only the collection time point, location and ward will be marked on the swab tubes. After informed consent, vaginal swabs will be collected during speculum examination from the lateral vaginal wall and posterior fornix vaginae using a sterile cotton swab combined with an epithelial brush. A rectal swab will be collected by insertion of a sterile swab into the anal sphincter. Intraoperative swabs of the placenta and uterine cavity will be collected during caesarean section under sterile conditions. Neonatal swabs (buccal mucosa and skin) will be collected directly after delivery and in the neonatal period. Stool samples will be taken from the meconium, defined as first stool of the infant and the stool of the newborn in the neonatal period. All specimens will immediately be stored at -80°C after collection. The epithelial brush will be put into RNAlater® RNA stabilization solution and stored at -80°C.

Microbiome analysis:

Microbiome analysis will be performed at the Joint Microbiome Facility (JMF) of the Medical University of Vienna and the University of Vienna. Testing will be performed by sub- investigators at the JMF. The microbial community composition in collected stool swab samples will be determined by 16S rRNA gene amplicon sequencing. Briefly, DNA will be extracted with the QIAamp Microbiome Kit or QIAamp DNA Mini Kit (for swab and stool samples, respectively), followed by 16S rRNA gene amplification and barcoding as previously described. Multiplexed amplicon samples sequenced on the Illumina MiSeq platform at the JMF. Negative controls performed during DNA extraction and 16S rRNA gene amplification are routinely included in the sample processing workflow. The obtained sequence data will be quality-filtered and demultiplexed, followed by amplicon sequencing variant (ASV) inference with DADA2,16 enabling analysis at the highest possible taxonomic resolution. Resulting ASV sequences will be taxonomically classified using SINA with the newest release of the the SILVA SSU rRNA database. If necessary, contaminants will be removed in silico using the decontam software package.

Perinatal data:

In addition to swab sampling and analysis, the following perinatal parameters will be collected, using the PIA Fetal Database, version 5.6.16.917 (GE Viewpoint, Munich, Germany): Maternal age [number], parity [number], tertiary education [yes/no], ethnicity [category], relationship status [category], body mass index [number], nicotine abuse [yes/no], history of pPROM [yes/no], history of PTB [yes/no], preexisting diseases [category], vaginal infection screening [yes/no], cervical insufficiency [yes/no], preeclampsia [yes/no], bleeding [yes/no], antenatal steroid prophylaxis [yes/no], ongoing antibiotic treatment [yes/no], tocolysis [yes/no], magnesium prophylaxis [yes/no], gestational week at delivery [number], birthweight [number], Apgar score at 1/5/10 minutes [number], umbilical cord arterial pH [number], transfer to neonatal intensive care unit [yes/no].

Study Type

Observational

Enrollment (Anticipated)

100

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

      • Vienna, Austria, 1090
        • Recruiting
        • Medical University of Vienna, Dept. of Obstetrics and Gynecology
        • Contact:
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Genders Eligible for Study

Female

Sampling Method

Non-Probability Sample

Study Population

A total of 100 study participants, meeting all inclusion and non exclusion criteria, will be included, assigned to one of the following groups:

Study group:

• This group will consist of 50 pregnant women, who experienced pPROM between 22+5 and 28+0 gestational weeks, either presenting at the primary study site, or being referred from other hospitals, and delivered at preterm by cesarean section.

Control group:

• This group will consist of 50 pregnant women, who are scheduled for elective cesarean section at the outpatient department of the primary study site, between a 32+0 and 37+0 gestational weeks, and delivered at term by cesarean section.

Description

Inclusion Criteria:

  • Maternal age ≥18 years at the time of study enrollment
  • Singleton pregnancy
  • Signed informed consent
  • Confirmed preterm premature rupture of membranes (pPROM) or elective cesarean section for term birth (depending on study group)
  • Gestational age at the time of pPROM between 22+5 and 28+0 weeks or ≥37+0 gestational weeks at the time of term cesarean section (depending on study group)

Exclusion Criteria:

  • Maternal age <18 years at the time of study enrollment
  • Multiple pregnancy
  • Inability to consent to the participation in the study
  • Ongoing antibiotic treatment or antibiotic treatment ≤2 weeks before study enrollment
  • Vaginal sexual intercourse within 48 hours before study enrollment
  • Fresh vaginal bleeding within 48 hours before study enrollment
  • Maternal Hepatitis-B or Hepatitis-C infection (i.e., positive on PCR)
  • Maternal HIV-infection (i.e., positive on PCR)
  • Maternal diabetes mellitus or gestational diabetes

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Case-Control
  • Time Perspectives: Prospective

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Study group
This group will consist of 50 pregnant women, who experienced pPROM between 22+5 and 28+0 gestational weeks, either presenting at the primary study site, or being referred from other hospitals, and delivered at preterm by cesarean section.
After informed consent, vaginal swabs will be collected during speculum examination from the lateral vaginal wall and posterior fornix vaginae using a sterile cotton swab combined with an epithelial brush. A rectal swab will be collected by insertion of a sterile swab into the anal sphincter. Intraoperative swabs of the placenta and uterine cavity will be collected during caesarean section under sterile conditions. Neonatal swabs (buccal mucosa and skin) will be collected directly after delivery and in the neonatal period. Stool samples will be taken from the meconium, defined as first stool of the infant and the stool of the newborn in the neonatal period.
Control group
This group will consist of 50 pregnant women, who are scheduled for elective cesarean section at the outpatient department of the primary study site, between a 32+0 and 37+0 gestational weeks, and delivered at term by cesarean section.
After informed consent, vaginal swabs will be collected during speculum examination from the lateral vaginal wall and posterior fornix vaginae using a sterile cotton swab combined with an epithelial brush. A rectal swab will be collected by insertion of a sterile swab into the anal sphincter. Intraoperative swabs of the placenta and uterine cavity will be collected during caesarean section under sterile conditions. Neonatal swabs (buccal mucosa and skin) will be collected directly after delivery and in the neonatal period. Stool samples will be taken from the meconium, defined as first stool of the infant and the stool of the newborn in the neonatal period.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Changes of the vaginal microbiome after pPROM in comparison to term births
Time Frame: Till July 2021
Abundance measurements (counts) of the amplicon sequence variants (ASVs), as well as ASV sum counts at higher taxonomic levels will be evaluated, to test for significant overlap or differences in microbial community composition in different sample groups. These parameters will be analyzed within each of the study groups, including longitudinal analyses to detect a potential difference from the onset of pPROM to the time of delivery or later (study group), or from pregnancy to the time of delivery or later (control group). In addition, ASVs and ASV sum counts will be compared between the study and control group at predetermined time points. Detection of significantly more abundant amplicon sequence variants between groups will be performed, and adjusted P-values will be calculated using the Benjamini-Hochberg method and differences supported with P- values <0.05 will be considered significant.
Till July 2021
Changes of the rectal microbiome after pPROM in comparison to term births
Time Frame: Till July 2021
Abundance measurements (counts) of the amplicon sequence variants (ASVs), as well as ASV sum counts at higher taxonomic levels will be evaluated, to test for significant overlap or differences in microbial community composition in different sample groups. These parameters will be analyzed within each of the study groups, including longitudinal analyses to detect a potential difference from the onset of pPROM to the time of delivery or later (study group), or from pregnancy to the time of delivery or later (control group). In addition, ASVs and ASV sum counts will be compared between the study and control group at predetermined time points. Detection of significantly more abundant amplicon sequence variants between groups will be performed, and adjusted P-values will be calculated using the Benjamini-Hochberg method and differences supported with P- values <0.05 will be considered significant.
Till July 2021
Changes of the placental microbiome after pPROM in comparison to term births
Time Frame: Till July 2021
Abundance measurements (counts) of the amplicon sequence variants (ASVs), as well as ASV sum counts at higher taxonomic levels will be evaluated, to test for significant overlap or differences in microbial community composition in different sample groups. These parameters will be analyzed within each of the study groups, including longitudinal analyses to detect a potential difference from the onset of pPROM to the time of delivery or later (study group), or from pregnancy to the time of delivery or later (control group). In addition, ASVs and ASV sum counts will be compared between the study and control group at predetermined time points. Detection of significantly more abundant amplicon sequence variants between groups will be performed, and adjusted P-values will be calculated using the Benjamini-Hochberg method and differences supported with P- values <0.05 will be considered significant.
Till July 2021
Changes of the uterine microbiome after pPROM in comparison to term births
Time Frame: Till July 2021
Abundance measurements (counts) of the amplicon sequence variants (ASVs), as well as ASV sum counts at higher taxonomic levels will be evaluated, to test for significant overlap or differences in microbial community composition in different sample groups. These parameters will be analyzed within each of the study groups, including longitudinal analyses to detect a potential difference from the onset of pPROM to the time of delivery or later (study group), or from pregnancy to the time of delivery or later (control group). In addition, ASVs and ASV sum counts will be compared between the study and control group at predetermined time points. Detection of significantly more abundant amplicon sequence variants between groups will be performed, and adjusted P-values will be calculated using the Benjamini-Hochberg method and differences supported with P- values <0.05 will be considered significant.
Till July 2021
Changes of the neonatal microbiome of neonates born after pPROM in comparison to neonates experiencing a term birth
Time Frame: Till July 2021
Abundance measurements (counts) of the amplicon sequence variants (ASVs), as well as ASV sum counts at higher taxonomic levels will be evaluated, to test for significant overlap or differences in microbial community composition in different sample groups. These parameters will be analyzed within each of the study groups, including longitudinal analyses to detect a potential difference from the onset of pPROM to the time of delivery or later (study group), or from pregnancy to the time of delivery or later (control group). In addition, ASVs and ASV sum counts will be compared between the study and control group at predetermined time points. Detection of significantly more abundant amplicon sequence variants between groups will be performed, and adjusted P-values will be calculated using the Benjamini-Hochberg method and differences supported with P- values <0.05 will be considered significant.
Till July 2021

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Collaborators

Investigators

  • Principal Investigator: Alex Farr, MD PhD, Medical University of Vienna
  • Study Chair: Herbert Kiss, MD MBA, Medical University of Vienna
  • Study Chair: Angelika Berger, MD MBA, Medical University of Vienna

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

July 27, 2020

Primary Completion (Anticipated)

July 1, 2021

Study Completion (Anticipated)

December 1, 2021

Study Registration Dates

First Submitted

July 20, 2020

First Submitted That Met QC Criteria

July 23, 2020

First Posted (Actual)

July 28, 2020

Study Record Updates

Last Update Posted (Actual)

September 2, 2020

Last Update Submitted That Met QC Criteria

September 1, 2020

Last Verified

September 1, 2020

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

Undecided

IPD Plan Description

Anonymized data if required and in accordance with data protection regulations

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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