Type 2 Diabetes – How Best to Predict Overweight Newborns?

A significant concern in Gestational or pregnancy induced diabetes is the likelihood the baby will be born overweight. This can lead to the need for…

  • a cesarean or C-section,
  • a broken shoulder during a vaginal birth, and
  • an increased risk of developing Type 2 diabetes down the track in both the mother and the child.

Obstetricians and midwives check for Gestational diabetes with the oral glucose tolerance test or OGTT, usually at between 24 and 28 weeks of pregnancy. According to work published in July of 2017 in the journal Diabetes Research and Clinical Practice, the body mass index (BMI) could be better than carrying out the oral glucose tolerance test for predicting overweight or large for gestational age (LGA) newborns.

Investigators at Tohoku University Graduate School of Medicine in Miyagi and several other research institutions in Japan, included 966 pregnant women in their study. They looked at…

  • the woman’s BMI before pregnancy,
  • fasting blood sugar, and
  • OGTT results at 22 weeks’ gestation.

Then they compared earlier findings with the birth weight of the infants. More infants whose mothers were overweight or obese before pregnancy were larger than those whose mothers had Gestational Diabetes. From this information, the researchers concluded the mother being overweight or obese predicted a large for gestational age newborn more accurately than testing for Gestational diabetes.

This is not to say Gestational diabetes is not a concern. Women diagnosed with diabetes during their pregnancy have a higher risk of producing a larger baby than those born to healthy mothers. The two conditions often go together. One way of avoiding developing diabetes during pregnancy is to reach and maintain a healthy weight before and during pregnancy and gain only the amount recommended.

Average birth weight ranges from 5.5 pounds to 8.0 pounds. Large for gestational age at birth is defined at 8 pounds 13 ounces, or 4,000 grams. Most large for gestational age infants are born at 37 to 41 weeks of pregnancy or gestation, but some may be born earlier or later. Premature babies can be large for gestational age at lower weights than those born at the normal pregnancy duration. At any given stage of pregnancy, newborns are classed as being large if they are born at the 90th percentile for weight.

In 2015…

  • approximately 7 percent of infants born in the United States weighed over 4000 grams.
  • one percent weighed over 4500 grams, and
  • 0.1 percent weighed more than 5000 grams.

Throughout the world, birth weight differs by socioeconomic factors. Different standards for a large for gestational age (LGA) newborn, make it difficult to compare numbers from one country to the next.