Investigating the role of hormones and microbiome in pregnancy during assisted reproduction

Prospective, Clinical Cohort Study on the Endocrinology and Vaginal/Endometrial Microbiome of the Luteal Phase and Pregnancy After Embryo Transfer in Assisted Reproduction

Observational University of Luebeck · NCT03507673

This study is trying to see how hormone levels and the bacteria in the vagina and uterus affect early pregnancy in women undergoing assisted reproduction with frozen embryos.

Quick facts

Study typeObservational
Enrollment1200 (estimated)
Ages18 Years to 45 Years
SexFemale
SponsorUniversity of Luebeck Academic / other
Locations5 sites (Saarbrücken, Saarland and 4 other locations)
Trial IDNCT03507673 on ClinicalTrials.gov

What this trial studies

This observational study aims to explore the relationship between progesterone levels and the vaginal/endometrial microbiome during the luteal phase in patients undergoing assisted reproduction. It focuses on determining the timing of the luteoplacental shift, which is crucial for maintaining early pregnancy. Blood samples and microbiological swabs will be collected from participants who are transferring cryopreserved embryos to assess these associations. The study seeks to fill gaps in understanding how hormonal and microbiological factors may influence pregnancy outcomes.

Who should consider this trial

Good fit: Ideal candidates for this study are women aged 18 to 45 who are undergoing the transfer of cryopreserved embryos.

Not a fit: Patients undergoing fresh IVF/ICSI embryo transfers or those with uterine malformations or endometrial abnormalities may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could enhance understanding of factors affecting pregnancy maintenance, potentially leading to improved fertility treatments.

How similar studies have performed: While some studies have explored aspects of the microbiome in relation to fertility, this specific investigation into the interplay between progesterone and the microbiome during the luteal phase is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. Patients aged 18 to 45 years
2. Transfer of cryopreserved embryos

Exclusion Criteria:

1. Fresh IVF/ICSI embryo transfer cycle
2. Evidence for ovulation on ultrasound previous to embryo transfer confirmed by a follicle ≥14mm or by a progesterone ≥1.0 µg/l in programmed cycles
3. Uterus malformations, endometrial abnormalities (on ultrasound or diagnosed by previous hysteroscopy)

Where this trial is running

Saarbrücken, Saarland and 4 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Infertility
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.