Researchers studied a hormone called kisspeptin in women who struggle to get pregnant or have experienced miscarriages. They found that women who cannot conceive have lower levels of this hormone compared to women who have had miscarriages. The study also looked at genes and blood markers that might affect kisspeptin levels, but didn’t find strong connections. While these findings are interesting, scientists say more research is needed to fully understand how kisspeptin affects fertility and whether it could help treat pregnancy problems in the future.

The Quick Take

  • What they studied: Whether a hormone called kisspeptin is different in women who can’t get pregnant versus women who have had miscarriages, and if genes and blood tests can explain these differences.
  • Who participated: 76 women total: 46 women struggling to become pregnant and 30 women who had experienced miscarriages. All were adults seeking medical help for reproductive issues.
  • Key finding: Women who couldn’t get pregnant had noticeably lower kisspeptin levels than women with miscarriage histories. The difference was statistically meaningful, though the study was relatively small.
  • What it means for you: This suggests kisspeptin might be important for fertility, but it’s too early to use this information for treatment decisions. Talk to your doctor about fertility concerns rather than focusing on kisspeptin levels right now.

The Research Details

This was a cross-sectional study, which means researchers took a snapshot in time by comparing two groups of women at the same moment. They measured kisspeptin levels in blood samples from women with infertility and women with miscarriage histories, then compared the results between groups.

The researchers also tested each woman’s blood for other hormones and nutrients (like thyroid hormones, vitamin B12, and folate) that might affect fertility. They also looked at each woman’s genes, specifically two variations in a gene called MTHFR that some people inherit. This gene affects how the body processes certain B vitamins.

By collecting all this information at one time point, the researchers could see if kisspeptin levels differed between groups and whether the gene variations or other blood markers explained those differences.

This research approach is useful for spotting patterns and differences between groups, which can suggest what might be important for fertility. However, because it’s a snapshot rather than following women over time, it can’t prove that low kisspeptin actually causes infertility—only that the two seem connected.

The study has moderate reliability. Strengths include measuring multiple hormones and nutrients, which gives a complete picture. Weaknesses include the small sample size (76 women), which limits how much we can trust the findings. The study was also conducted in one location, so results might not apply to all populations. The researchers didn’t find connections between kisspeptin and the genes they studied, which suggests the relationship is complex and needs more investigation.

What the Results Show

The main finding was that women unable to conceive had significantly lower kisspeptin levels compared to women with miscarriage histories. The difference was noticeable enough to be unlikely due to chance alone (p=0.019), and the effect size was moderate (Cohen’s d=0.62), meaning the difference was meaningful but not enormous.

Interestingly, women with infertility had higher vitamin B12 levels than women with miscarriage histories. This was also statistically significant but the difference was smaller. The researchers measured many other blood markers including thyroid hormones, folate, ferritin, prolactin, and homocysteine, but found no differences between the two groups in these measurements.

When the researchers looked at the MTHFR gene variations, they found no differences in how common these genetic variations were between the two groups. Additionally, kisspeptin levels didn’t seem to be connected to any of the other blood markers or gene variations they measured.

The higher vitamin B12 levels in infertile women were unexpected and not fully explained by the study. This could suggest different nutritional patterns or metabolism between groups, but more research is needed. The lack of differences in thyroid hormones, folate, and other markers suggests that infertility and miscarriage may involve different biological pathways than previously thought.

Previous research has shown that kisspeptin is important for reproductive function in animals and humans. This study adds to that knowledge by showing that kisspeptin levels differ between women with infertility and those with miscarriage histories, suggesting the hormone may play different roles in these two conditions. However, the study doesn’t explain why these differences exist or whether low kisspeptin actually causes infertility.

The study had several important limitations. First, the sample size was small (only 76 women), which means results might not apply to larger populations. Second, it was a snapshot study, so researchers couldn’t determine whether low kisspeptin causes infertility or if infertility causes low kisspeptin. Third, the study didn’t include a healthy control group of women without fertility problems, making it harder to know what ’normal’ kisspeptin levels should be. Finally, the researchers only measured kisspeptin once, so they couldn’t track how levels change over time.

The Bottom Line

At this time, there are no specific recommendations based on this research. The findings suggest kisspeptin may be involved in fertility, but the evidence is not strong enough to guide treatment decisions. If you’re struggling with infertility or miscarriage, work with a fertility specialist who can evaluate your individual situation and recommend evidence-based treatments. Do not seek kisspeptin testing or treatment outside of a medical setting based on this single study.

Women experiencing infertility or recurrent miscarriages should be aware of this research as it may eventually lead to new treatments, but shouldn’t change their current care. Fertility doctors and researchers should pay attention to these findings as they suggest kisspeptin deserves further investigation. General readers should understand this is early-stage research, not a breakthrough ready for clinical use.

Even if kisspeptin becomes a treatment target, it would likely take 5-10 years of additional research before any new therapies based on this work could be available to patients. Current fertility treatments remain the evidence-based options.

Want to Apply This Research?

  • If using a fertility tracking app, continue logging menstrual cycles, ovulation signs, and any medical appointments. Note any blood work results your doctor shares, including hormone levels, as this creates a personal health record to discuss with your fertility specialist.
  • Use the app to maintain consistent communication with your healthcare provider by logging symptoms and questions about your fertility journey. Set reminders for scheduled appointments and blood work, which are important for monitoring reproductive health.
  • Track your overall reproductive health markers over time through your medical team rather than focusing on any single hormone. Work with your doctor to establish baseline measurements and monitor changes during fertility treatment, creating a comprehensive picture of your health.

This research is preliminary and should not be used to make medical decisions about fertility treatment. Kisspeptin testing and treatment are not currently standard medical practice. If you are experiencing infertility or recurrent miscarriages, consult with a board-certified fertility specialist or reproductive endocrinologist who can provide personalized evaluation and evidence-based treatment options. This article is for educational purposes only and does not replace professional medical advice.