Miscarriage Risk Linked to High Body Mass Index by Mark Perloe, M.D.
Posted Feb 16 2009 12:00am
Miscarriage Risk Linked to High Body Mass Index by Mark Perloe, M.D. New evidence shows that maintaining a low Body Mass Index (BMI) is an important factor in lowering the risk of miscarriage. This finding, from a study presented at this year's annual meeting of the American Society for Reproductive Medicine (ASRM), is significant. It showed that a BMI of 25 or higher produced more (53%) first-trimester miscarriages of a genetically normal fetus than a BMI that fell below 25 (37%), according to Dr. Innes V. Landres, a chief resident in obstetrics and gynecology at Standford University.
Dr. Landres' controlled, long-term study (1999-2008) looked at 204 women with first-trimester miscarriages. The women were divided into two groups; one consisted of those with a BMI of 25 or greater, and the other with BMIs less than 25. Women over 39 were excluded because of their increased risk of miscarriage. The groups had similar pregnancy histories and used comparable assisted reproductive methods. Weight has always been a factor for a successful pregnancy, and there is some evidence that obesity predisposes women to miscarriages, even those with ovum donation. Obesity also has been linked to recurring pregnancy loss and spontaneous abortions, although most miscarriages are a result of fetal aneuploidy, where the chromosome numbers are not properly balanced. The California study, however, focuses on the role of weight in carrying an otherwise normal pregnancy to term.
According to the ASRM, twelve percent of all infertility cases are a result of either weighing too much or too little. "Maintaining a healthy body weight may increase your chances of a successful and healthy pregnancy," Dr. Mark Perloe, Medical Director at Georgia Reproductive Specialists, explains. He suggests that, "since BMI (unlike age) is a modifiable risk factor, tracking your BMI is another tool for reducing your risk of a miscarriage."
What is BMI? BMI, Body Mass Index, is a good indicator of how much fat you carry. It is a measure of a person's weight in relation to her height, not one of body composition. A BMI score between 20 and 25 is considered ideal. A score below 18.5 indicates that one is underweight, while a score between 25 and 29 indicates overweight. The results of the California study suggest that a BMI over 25 seems to be a risk factor for miscarriage, and that lifestyle modification is important to help lower that risk.
You can compute your BMI with this formula. Weight in pounds / (height in inches x height in inches) x 703. So, if you weigh 120 pounds and are five feet, five inches tall, your BMI is 120 divided by (65 x 65 = 4225), or 120/4225 x 703. That gives you a BMI of 19.97. or use this simple chart