Getty: H. Armstrong Roberts

Getty: H. Armstrong RobertsMaintaining a healthy weight is especially important, if you are planning to become pregnant, according to experts from Boston University School of Public Health. In new research, they found a link between obesity and infant death.

Maintaining a healthy weight is especially important, if you are planning to become pregnant, according to experts from Boston University School of Public Health. In new research, they found a link between obesity and infant death.

The study could not confirm a direct cause-and-effect connection, but after reviewing information on millions of newborns, Eugene Declercq, PhD, a Boston University expert in maternal health and the study’s lead author, said, “there is a need for more open, honest discussions about avoiding the possible risks of maternal obesity in infant health.”

For the study, Declercq led a group of researchers who analyzed information from more than 6 million newborns, born in 38 states, between 2012 and 2013.

They found that babies born to obese women were twice as likely to die from preterm birth-related causes than those born to normal-weight women.

Infants born to obese women were also more likely to die from birth defects and sudden infant death, the study showed. The more obese the mother, the greater the risk of infant death (death in the first year of life). Controlling weight gain during the pregnancy (limiting it to 25 pounds) had little effect on the risk of infant death or poor health outcomes in the obese group.

The research is the second, recent large-scale study to find that a woman’s weight can adversely impact the health of fetus or infant. The first found a link between obesity during pregnancy and stillbirth.

Understanding Body Weight

Obesity is a word used so often that many women may be unsure if it even refers to them. Obesity is best determined by a measure called Body Mass Index (BMI), not just weight. BMI is a formula that helps determine how much of your body is lean and how much is fat.

This BMI Calculator, provided by the Centers for Disease Control and Prevention, can be used to see where you are on the scale explained on the chart below:

If your BMI is less than 18.5, it falls within the underweight range.

If your BMI is 18.5 to 24.9, it falls within the normal or healthy weight range.

If your BMI is 25.0 to 29.9, it falls within the overweight range.

If your BMI is 30.0 or higher, it falls within the obese range.

Getty: H. Armstrong Roberts

BMI is a good guideline, but it does not take into account age, gender, or muscle mass. Nor does it distinguish between lean body mass and fat mass. So, many health experts suggest adding additional measurements, particularly if you are on the border of the overweight or obese category.

Another, simpler measure is waist circumference. You are obese if your waist is larger than 35 inches (40 inches for men). More than 57 percent of black women older than 20 are considered obese.

In addition to dramatically increasing the risk of developing diabetes, heart disease, and cancer, obesity imbalances the body’s hormones in ways that may affect fertility or pregnancy.

“The findings suggest that primary care clinicians, ob-gyns and midwives need to have conversations about weight as part of well-woman care, and when women are contemplating getting pregnant,” Declercq said in a university news release.