How Insulin Resistance Affects Fertility
Insulin resistance describes a reduced response of the body's cells to insulin, with the body compensating by producing more of it. Its relevance to fertility comes from the effect that has on hormone balance.
This article explains, for information, how insulin resistance influences ovulation, how it is assessed, and how it relates to polycystic ovary syndrome.
What is insulin resistance?
Insulin is the hormone that moves sugar from the blood into the cells. When cells respond less to that signal, the pancreas releases more insulin to compensate.
Blood sugar can stay normal for a time, but circulating insulin is high. That raised insulin can in turn act on the reproductive hormones.
How does it affect ovulation?
High insulin levels can increase androgen production in the ovaries and reduce the liver's production of hormone-carrying proteins.
The result can be disrupted follicle maturation and irregular ovulation, which often shows up as an irregular cycle.
What are the signs?
Insulin resistance can be silent. Possible findings include:
- Irregular or infrequent periods
- Weight gain around the waist
- Marked tiredness and sugar cravings after meals
- Darkened skin at the neck or underarms (acanthosis nigricans)
- Increased hair growth and oilier skin
How is it assessed?
Assessment usually starts with fasting glucose and fasting insulin, from which index values can be calculated. A glucose tolerance test is requested where needed.
Other hormones such as thyroid and prolactin are reviewed alongside it when cycles are irregular, see high prolactin and fertility.
How is it approached?
The foundation is lifestyle: balanced eating, regular physical activity and a sustainable weight. Medication may be considered by your doctor where appropriate.
These measures can support the return of a more regular ovulation pattern. Response varies between individuals and the process is followed by your doctor.
Why it matters in IVF
Insulin resistance is taken into account when planning treatment, and the stimulation protocol and monitoring are individualised accordingly.
In patients with PCOS and a high ovarian response, closer monitoring for OHSS also applies.
Related Reading
- PCOS and Getting Pregnant: Symptoms, Diagnosis and Fertility Options
- How Weight and BMI Affect Fertility
- Ovulation Explained: When It Happens and How to Find Your Fertile Window
Sources and references
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