IVF and Underweight Patients: Why Your Weight Is a Factor

Becoming pregnant depends on a complex set of factors, especially if you suffer from male or female infertility. If you’ve been struggling to conceive, our fertility specialists may suggest IVF (in vitro fertilization), a treatment that involves harvesting eggs and sperm, combining them in our lab, and implanting them directly into the woman’s uterus. This advanced technique has helped millions of people achieve their family goals. IVF is a lengthy, nuanced process that can be emotionally, physically, and financially taxing, so we work to help our patients optimize their chances for success. In many cases, making simple lifestyle changes can improve your likelihood of pregnancy with IVF. For that reason, we work to educate our patients about the connection between IVF and underweight patients at our San Antonio practice. Read on to find out more about this little-understood link between a woman’s weight and her ability to conceive with IVF.

Why Does Weight Impact Conception and Pregnancy?

Your weight is often an indicator of your overall health. You may know that being overweight or obese can interfere with your ability to become pregnant, but it turns out that being underweight can be just as detrimental, if not more. Having a lower BMI (body mass index, a basic test used to categorize patients’ weight) can affect your fertility in the following ways:

• It lowers your estrogen levels. As you may know, estrogen is a vital female hormone that helps catalyze ovulation and maintain a healthy pregnancy. Women who are underweight usually produce less estrogen.
• It may prevent you from ovulating properly. Women with reduced BMIs more commonly experience anovulation, a condition in which they stop ovulating on a routine basis or even entirely. Women suffering from anovulation may or may not menstruate.
• It raises your risk for miscarriage if you do become pregnant. Underweight women are more than 70 percent more likely to suffer from miscarriage than those at a healthy weight, according to a study by the European Food and Information Council.
• It may mean that you exercise excessively. Some women are naturally thinner, but if you are underweight because you overstrain your body, this heightened activity can reduce your chances for conception.

Studies on IVF in Underweight Patients

Scientists and fertility specialists have recently begun investigating underweight patients’ IVF success rates. Here’s what they found:

• In 2010, out of more than 1,000 Chinese test subjects, 31 percent of those who were underweight (with a BMI lower than 18.5) conceived with IVF, while 37 percent of those who were at a healthy BMI (between 18.5 and 23.9) became pregnant.
• At the Advanced Fertility Center of Chicago, a 2011 study of 2,500 women revealed that 50 percent of normal weight women conceived with IVF, 45 percent of overweight women became pregnant, and only 34 percent of underweight patients conceived. This research shocked many people because it demonstrated that overweight women are more likely to have a successful IVF cycle than underweight patients.

Should You Gain Weight Before IVF?

If your BMI is less than 18.5, it may benefit you to try and put on some extra pounds before you begin your IVF cycle. However, there is a right and a wrong way to gain weight. Our fertility specialists recommend that underweight patients improve their BMIs by:

• Consuming healthy, calorie-dense proteins, nuts, whole grains, and dairy products
• Adding protein supplements such as smoothies or bars
• Eating more frequent snacks and meals

You should also remember that your BMI is not the only aspect of your health that can influence your IVF success. If you’re ovulating properly and have healthy hormone levels, you may not need to worry about your weight. Our doctors provide fertility evaluation services to determine if your weight may be a contributing factor in your infertility and chances of conception with IVF.

Contact the Fertility Center of San Antonio to Find Out More

Are you underweight and planning to undergo IVF? Learn more about how to optimize your likelihood for pregnancy by contacting our practice today to schedule a consultation.