Exposing Newborns Delivered by Cesarean to Maternal Microbiota
Tests exposing cesarean-born newborns to maternal birth canal microbes to study allergy risk.
Plain-language title generated from the registry record
Registry title: Restoration of Microbiota in Neonates
Key facts
- Where
- Stockholm, SwedenSee the site
AI summary: who the study is looking for
From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.
The trial is looking for newborns of healthy mothers with uncomplicated full-term pregnancies. It studies whether exposing C-section babies to the mother's birth canal bacteria affects the baby's microbiome, immune system and allergy risk.
- Age
- Newborns aged 5 minutes to 15 minutes.
- Sex
- Babies of any sex can join.
- Biomarker or test result
- For mothers in the C-section groups, vaginal pH of 4 or lower at the time of birth.
Main reasons for not taking part
- Mothers with pre-eclampsia or a complicated pregnancy
- Mothers under 18 or over 40 years of age
- Mothers with genital herpes simplex, genital warts, HIV or hepatitis B
- Babies born before 37 weeks of pregnancy
- C-section group: mothers positive for Group B or Group A Streptococcus, or with bacterial vaginosis
Read by machine on 12 November 2026.
Where in Sweden
- Karolinska InstitutetStockholm, SwedenContact: Marica C Hamsten, MScTaking people
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Contact the study team: see the registry record → Contacts and Locations
Print a page for my doctorTrial details
- Who runs it
- Karolinska Institutet
- Trial code
- NCT03928431
- Record updated
- 1 July 2025
- Original description
The aim of the study is to examine the effect of exposure of cesarean section (CS) delivered neonates to a natural condition of birth, i.e. to the microbiota of the birth canal, on the acquisition of microbial genes during development of the microbiome at multiple body sites, immune system maturation and allergy risk in childhoodRead full original descriptionShow less
Restoration of Microbiota in Neonates - a Randomized Controlled Trial
The aim of the study is to examine the effect of exposure of cesarean section (CS) delivered neonates to a natural condition of birth, i.e. to the microbiota of the birth canal, on the acquisition of microbial genes during development of the microbiome at multiple body sites, immune system maturation and allergy risk in childhood
Inclusion: Infants of healthy mothers with uncomplicated pregnancies at term, mothers of any ethnic or social background that can speak, read, and understand Swedish to the extent that they can consent in Swedish. An additional inclusion criterion for mothers in the CS groups is vaginal pH ≤ 4 at the time of birth.
Exclusion: Infants of mothers with pre-eclampsia or complicated pregnancies, mothers <18 years or >40 years of age, genital herpes simplex, genital warts, HIV, Hepatitis B or complications during delivery, infants delivered prior to 37 weeks of gestation. Additional exclusion criteria for mothers in the CS group: Mothers positive to Group B Streptococcus, Group A Streptococcus, bacterial vaginosis, vaginal pH > 4 at the time of birth. Mothers with fecal samples positive for Salmonella, Shigella, Campylobacter or Yersinia.