Does My Weight Really Affect My Chances of Getting Pregnant?

From the media to our own friends and loved ones, women experience so much pressure to be the “perfect” weight. In reality, of course, every body is beautiful and all women can live a healthy lifestyle regardless of the number on the scale. But if you’re trying to get pregnant, it’s helpful to learn about how your weight can affect your likelihood of conceiving. You should know that being extremely overweight or extremely underweight can both affect your hormones, making it more difficult to get pregnant.

On one end of the spectrum, women who are very overweight may have a more difficult time getting pregnant. This is because fat cells in your body actually play a role in regulating estrogen. Fat cells absorb and slowly release estrogen, so the more fat cells you have, the more estrogen they release. Normally, the amount of estrogen in your body ebbs and flows throughout the month, spiking quickly on day one of your cycle. This spike tells your pituitary glands to produce follicle-stimulating hormone (FSH), the hormone that signals to your ovaries to start maturing an egg.

Because the estrogen from your fat cells is released steadily throughout the month, women with very high body fat won’t experience the same initial spike in estrogen. This leads to less FSH production, meaning that the ovarian follicle—the maturing egg—won’t grow as quickly, lessening your likelihood of conception.

There are other ways being very overweight can affect your reproductive health. Estrogen signals to your uterus to start building up the thick, nutritious endometrium that nourishes an embryo if you get pregnant, or sloughs off through menstruation if you don’t. If you’re very overweight, a continuous stream of estrogen from your fat cells can signal to your body to continue building up this uterine lining throughout the month, and this extreme buildup can actually increase your risk of endometrial cancer.

On the other end of the spectrum, being very underweight can negatively impact your fertility, too—especially if you are living with anorexia. Your hormones are regulated by your hypothalamus, a part of the brain responsible for your most important, automatic functions, like your metabolism and hormones. When someone has anorexia, the section of their hypothalamus that controls appetite stops working properly. Without this hormonal signal, your body won’t secrete enough FSH and LH to keep your eggs maturing and your menstrual cycle running smoothly. That’s why if you do have an eating disorder, it can be a great idea to focus on recovery and healing before trying to get pregnant.

Discussions of weight can be fraught with judgement and self-criticism. But weight shouldn’t be yet another yardstick against which to measure yourself. Instead, think of this information as another tool in your pocket. Focusing on a healthy diet and exercise can be a great way to increase your chances of getting pregnant, no matter your weight.