Ketogenic diet restores menstrual cycles and boosts fertility in women with PCOS

By Priyanjana Pramanik, MSc.Reviewed by Susha Cheriyedath, M.Sc.Sep 15 2024

Research reveals that a ketogenic diet not only restores menstrual cycles but also significantly increases pregnancy rates in women with PCOS, offering hope for those struggling with infertility. 

Study: Ketogenic diet improves fertility in patients with polycystic ovary syndrome: a brief report. ​​​​​​​Image Credit: Lightspring / Shutterstock

In a recent study published in the journal Frontiers in Nutrition, researchers investigated the effects of a ketogenic diet (KD) on restoring regular menstrual cycles and fertility in individuals with polycystic ovary syndrome (PCOS).

Their findings indicate that the KD significantly improved menstrual regularity, with a 55.6% pregnancy rate among those desiring pregnancy, suggesting it may be a promising approach for enhancing fertility in women with PCOS.

Background

PCOS is a common condition affecting up to 20% of women of reproductive age and is a leading cause of infertility due to irregular ovulation.

Obesity, which is closely linked to PCOS, affects up to 75% of women with the condition and contributes to hormonal imbalances that prevent ovulation.

Diet and insulin-sensitizing treatments can improve fertility, and the KD, known for its ability to promote weight loss and improve metabolic health, has gained attention as a potential treatment for PCOS.

While small studies have shown that KD can help with weight loss and hormone balance in women with PCOS, its impact on fertility has not been well-studied.

About the study

This study aimed to investigate the use of a KD to help women with PCOS restore regular menstruation and achieve pregnancies. The research used medical records from a clinic's electronic system and included women enrolled in the clinic's weight management program from 2017 to 2019.

The program offered monthly group appointments where patients received guidance from dietitians, exercise specialists, and endocrinologists.

The ketogenic diet involved limiting carbohydrate intake to 20 grams daily, with specific protein and fat guidelines. Women followed this diet for three months or more unless they became pregnant before that.

The study excluded those who did not adhere to the diet for at least three months, those who used contraception, or postmenopausal women. A total of 30 women met the study's criteria.

Participants had monthly check-ups to monitor their weight, overall health, and menstrual cycles. Metformin and ovulation-inducing medications were offered to women who needed them.

The study's main focus was on the return of regularity to menstrual cycles and pregnancy rates, with additional attention on the time taken to conceive and any weight changes. Statistical tests were used to compare the results between different groups of women based on their treatments.

Findings

The average age of participants was 31 years, and their average body mass index (BMI) was 43.4. Of the participants, 60% used metformin, and 60% also expressed a desire to become pregnant.

After six months, 92% of the women regained regular menstrual cycles; by 15 months, all had regular cycles. On average, participants lost 7.1 kg during this time.

Of the 18 women who wanted to conceive, 55.6% became pregnant, with 63% achieving pregnancy within 12 months. Those who became pregnant and those who did not both experienced similar weight loss.

The use of metformin did not significantly affect the return of regular menstruation, although all women, whether taking metformin or not, eventually regained menstrual regularity.

Interestingly, all women who did not take metformin achieved pregnancy, compared to 38.5% in the metformin group. Ovulation induction agents were not shown to significantly improve pregnancy rates.

For women with available anti-mullerian hormone (AMH) data, those with lower AMH levels struggled to conceive, even with fertility treatments. This highlights the potential role of AMH in pregnancy outcomes for women with PCOS.

Conclusions

This study highlights that a KD may improve menstruation regularity and increase pregnancy rates in women who have PCOS. Compared to previous research, pregnancy rates were notably higher, both with and without the use of ovulation-inducing agents.

The findings suggest that weight loss and improved insulin resistance, facilitated by the KD, are key factors in enhancing fertility for this population.

The study contributes valuable insights as one of the first to examine the effects of KD on fertility in women with PCOS. It also showed that even minimal weight loss combined with insulin resistance improvement could increase pregnancy rates.

However, the sample size was relatively small, and the long-term effects of KD on fertility were not evaluated. Furthermore, the study did not compare KD with other diets in detail, nor did it assess the potential long-term adverse effects of KD in women with PCOS.

More extensive studies with larger sample sizes are needed to confirm the long-term impact of KD on fertility and to compare KD's effects with other dietary approaches.

Additionally, exploring the physiological mechanisms, such as improvements in insulin resistance and reproductive hormone regulation, could provide deeper insights into how KD influences fertility.