The reasons that a woman may struggle to get pregnant are many. Somewhere between 33% to 50% of infertile women have problems with ovulation. Other women may face anatomical problems that interfere with fertility, like blocked fallopian tubes or endometriosis.
A woman’s weight can also impact her fertility. As explained here, a woman who is overweight or obese can have elevated levels of estrogen due to an overabundance of estrogen-producing fat cells. And this estrogen imbalance can disrupt ovulation and menstruation.
Now, some new research sheds some light on the link between obesity and infertility.
via Science Daily: The findings challenge the widely held belief that infertility is a result of insulin resistance — a body’s insensitivity to chronically elevated insulin levels and a hallmark of obesity — and suggest a new culprit: heightened sensitivity to insulin’s effects on the pituitary gland.
The research was done at Johns Hopkins Children’s Center, using mice, not humans, with either intact or missing insulin receptors in their pituitary glands. The hope is to be able to improve fertility by reducing the pituitary gland’s sensitivity to insulin. One caveat is that in the study, the obese mice with missing insulin receptors still weren’t as fertile as lean mice with normal insulin levels. This might mean that the ovaries, in addition to the pituitary gland, could also be affected by high insulin levels.
Being overweight or underweight can cause fertility issues, because either state can cause irregular menstrual cycles. And when your menstrual cycle is unpredictable, it’s trickier to track your ovulation and pinpoint the days when you will be at your most fertile.
Related: Understand & track your ovulation, Heavier women have higher risk of miscarriage after IVF,The impact of your weight on your fertility, Struggling to conceive? Get guidance based on where you are in your fertility journey