Should You Lose Weight Before Getting Pregnant?

Gabriella Irving’s doctor didn’t mince words when she sought his advice after a year of trying to conceive. “He told me I had to lose weight,” the Surrey, B.C., mother recalls.

Irving left her doctor’s office determined to improve her diet and start exercising to help deal with her polycystic ovary syndrome (PCOS), a hormonal disorder affecting six to 10 percent of women, and a common cause of infertility. “I knew I had to do this,” she says. Within nine months, Irving had dropped 25 lbs. and was holding a positive pregnancy test in her hand.

A growing number of Canadian women are grappling with whether they should try to lose weight before trying to conceive: While 44 percent of women 18 years or over were overweight or obese back in 1978, according to Statistics Canada by 2004, that number had increased to 53.4 percent.

The list of reasons for trying to achieve a healthy weight provides plenty of motivation. Outcomes are better for mother and baby if a woman is at a healthy BMI when she becomes pregnant.

What’s your BMI

BMI stands for Body Mass Index, a calculation that provides an ideal weight range for individuals over 18, based on the ratio of weight-to-height. Although popular, the BMI does have limitations and is just one tool your doctor may use to access your weight.

The higher your BMI, the higher your risk of developing certain diseases, including heart disease, high blood pressure, and type 2 diabetes. Obesity (a BMI over 30) is associated with an increased risk of infertility, miscarriage, stillbirth, preterm labour, gestational diabetes, gestational hypertension, caesarean section, as well as giving birth to a very large baby or a baby with a birth defect. But losing weight can be a daunting task nonetheless. Here’s what experts suggest.

Find out if you need to lose weight. The Society of Obstetricians and Gynaecologists of Canada recommends having a BMI of under 30 (ideally between 18.5 and 24.9) prior to trying to conceive. A BMI between 18.5 and 24.9 is considered normal, between 25.0 and 29.9 is considered overweight, and 30 and over is considered obese. Health risks rise again when your BMI drops below 18.5, so you don’t want to bring that BMI down too low.

It’s important to discuss your BMI and any changes to diet and exercise with your health care provider if you’re thinking about having a baby.

There are plenty of BMI calculators online (the Canadian Diabetes Association offers one at diabetes.ca).

Losing weight the healthy way

Avoid the deprivation trap. Though it can be tempting to drop the pounds as quickly as possible, crash diets can cause your body to crave the nutrients it’s missing, potentially triggering a binge, warns Thornhill, Ont., registered dietitian Wendy Reingold.

A healthier and more sustainable approach to weight loss involves feeding and enriching your body with nutrient-dense foods and developing a healthy eating plan that will carry you through pregnancy, breastfeeding, and beyond, she notes.

Time your nutrition makeover for three to six months before you plan to start trying to conceive.

“When you’re losing weight, toxins get liberated back into your system after being stored in fat cells. You need time to detoxify via the liver, kidneys, and digestive system,” explains Lianne Phillipson-Webb, author, nutritionist, and founder of Sprout Right, a company that specializes in preconception, prenatal, and postnatal nutrition for women. You want to allow time for this process to occur before you become pregnant to minimize potential exposure to a growing fetus.

Be kind to yourself. Knowing that she was already carrying around extra weight from her first two pregnancies motivated Annette Intenberg, of Edmonton, to lose 88 lbs.

Before conceiving her third child. She also didn’t want her two older boys (now 8 and 6) to grow up with the same unhealthy eating habits as herself and her husband. “I started thinking, ‘What kinds of lessons are we teaching them? It was time to make a change.’”

Though she gained more weight than she’d planned during her pregnancy, Intenberg says she’s working hard at being kind to and patient with herself about the extra pounds she’s currently carrying around. “I remind myself. ‘You just had a baby. You’re still breastfeeding. Give it time.’”