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NCT Number: NCT06007560

Aerobe Cycling Training in Women With Unexplained Recurrent Pregnancy Loss

In 50% of women with recurrent pregnancy loss (RPL) miscarriages are unexplained, therefore no therapeutic intervention is possible. In a pilot study, women with unexplained RPL showed less endometrial NK cells (eNK) compared to women with a previously uncomplicated pregnancy. It is known that eNK cells are important for embryo implantation during early pregnancy. Investigators presume that high sympathetic activity in these women is related to eNK cell number, function and phenotype and that exercise is an effective intervention to lower sympathetic activity and to influence the immune system, as especially peripheral NK cells have been assumed to be responsive to physical training. The investigators hypothesize that moderate exercise can lower the adrenergic tone of the sympathetic nervous system hereby influencing endometrial NK cells in women with RPL and eventually pregnancy outcome.

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This study is active but is not currently recruiting participants.

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Key information

Conditions

Recurrent Pregnancy Loss

Age range

Up to 40 year

Sex eligibility

Female

Study type

Interventional

Phase

Not applicable

Primary location

Maastricht UMC+, Maastricht, Netherlands

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Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • RPL defined as 2 or more unexplained pregnancy losses from the time of conception until 24 weeks of gestation, known cause for the miscarriages are the presence of thyroid abnormalities, anti-phospholipid syndrome, uterine malformation, and abnormal parental karyotype according to international guideline.
  • Couples should not be aiming to conceive during the time course of the exercise intervention.

Exclusion criteria

  • Age above 40 years
  • BMI above 40
  • Current use of immunosuppressive or biological drugs
  • Current use of hormone conceptive
  • HIV positivity
  • Current or recent (<2 weeks) symptomatic genital infection such as chlamydia, gonorroa, or pelvic inflammatory disease
  • Pre-existent diabetes mellitus, autoimmune disease or overt cardiovascular disease
  • Vaccination (i.e Covid) within 1 month prior to or during sampling and intervention
  • New pregnancy at time of measurements, breastfeeding
  • Current or recent (<2-3 months ago) pregnancy
  • (Physical) inabilities to follow moderate aerobe cycling training
  • Participants who are not capable of signing the informed consent

Treatment and study plan

Exercise

Other

Aerobe cycling training consisting of 12-weeks of HR-controlled training at 50-60% of VO2max (maximal oxygen uptake) for 1 hour, for 2 times (week: 1-6) to 3 times (week: 7-12) per week

Primary outcomes

  1. CD56 endometrial NK cell frequency

    Time frame: 3 months

    Change in CD56 eNK cell frequency measured as percentage of total lymphocyte or total CD56 population by flowcytometry.

  2. CD56 endometrial NK cell function

    Time frame: 3 months

    Change in CD56 eNK cell function measured as percentage of CD56 degranulation by flowcytometry.

Secondary outcomes

  1. CD56 endometrial NK cell phenotype

    Time frame: 3 months

    Change in CD56 eNK cell phenotype measured as percentage of (sub)population or mean fluorescent intensity respectively by flowcytometry.

  2. CD56 peripheral NK cell frequency

    Time frame: 3 months

    Change in CD56 pNK cell frequency measured as percentage of total lymphocyte or CD56 population by flowcytometry.

  3. CD56 peripheral NK cell function

    Time frame: 3 months

    Change in CD56 pNK cell function measured as percentage of CD56 degranulation by flowcytometry.

  4. CD56 peripheral NK cell phenotype

    Time frame: 3 months

    Change in CD56 pNK cell phenotype measured as percentage of (sub)population or mean fluorescent intensity respectively by flowcytometry.

  5. Vaginal microbiome

    Time frame: 3 months

    Change in taxonomic classification of vaginal microbiota of different subtypes but also classified in clustering of different subtypes.

  6. Metabolic syndrome parameters I

    Time frame: 3 months

    Change in cm waist circumference.

  7. Metabolic syndrome parameters II

    Time frame: 3 months

    Chance in mmHg blood pressure, both systolic as diastolic.

  8. Metabolic syndrome parameters III

    Time frame: 3 months

    Change in concentration (mg/dL) triglyceride.

  9. Metabolic syndrome parameters IV

    Time frame: 3 months

    Change in concentration (mg/dL) cholesterol levels.

  10. Metabolic syndrome parameters V

    Time frame: 3 months

    Change in concentration (mg/dL) blood sugar levels.

  11. Sympathetic activity

    Time frame: 3 months

    Change in baroreceptor sensitivity in ms/mmHg.

  12. Uterine blood flow

    Time frame: 3 months

    Change in pulsatility index, lower indicates better outcome.

  13. Physical fitness

    Time frame: 3 months

    Change in VO2max.

  14. Pregnancy rate and live birth rate after one year of intervention, higher rater indicate better outcome.

    Time frame: 3 months

    Questionnaire.

Sponsors and collaborators

Lead sponsor

Radboud University Medical Center

Other

Collaborators

  • Maastricht University Medical Center

Registry information

Acronym: HMOVE

Important dates

Study start
2022
Primary completion
2024
Study completion
2026
First posted
Aug 23, 2023
Registry last updated
Apr 6, 2025

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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