In January 2017, the journal Epidemiology reported on a study of weight gain patterns and Gestational diabetes. Researchers at the University of British Columbia in Canada and the University of Pittsburgh in the United States compared women delivering single infants between 1998 and 2010. These figures included …

  • 806 mothers with Gestational or pregnancy-induced diabetes and
  • 4,819 mothers who did not develop Gestational diabetes.

Both normal-weight and obese women gaining more than the recommended amount during their first three months of pregnancy increased the risk of developing Gestational diabetes. The results were similar in obese women.

Weight gain in pregnancy is made up of …

  • the baby's weight – normally 5.5 to 8.0 pounds,
  • the weight of the placenta – 2 pounds,
  • fat storage – 6 to 8 pounds,
  • increased blood volume – 3 to 4 pounds,
  • increased fluid volume – 2 pounds,
  • increased breast size – 1 to 3 pounds, and
  • larger uterus – 2 pounds.

According to the Mayo Clinic, appropriate weight gain is at least partially determined by the mother's weight-for-height (BMI) before conception …

  • underweight mothers with a BMI less than 18.5 – 28 to 40 pounds,
  • normal weight mothers with a BMI of 18.5 to 24.9 – 25 to 35 pounds,
  • overweight mothers with a BMI of 25 to 29.9 – 15 to 25 pounds,
  • obese mothers with a BMI of 30 or over – 11 to 20 pounds.

Ideally, women should gain 2 to 4 pounds during the first three months or first trimester, and a pound per week after that. If carrying twins, mothers should gain about 1.5 pounds during the second and third trimesters – the middle three and last three months of the pregnancy.

During an average pregnancy, women become slightly resistant to insulin, raising blood sugar levels to provide energy for their baby. Insulin resistance, when transported too far, can lead to Gestational diabetes, a condition similar to Type 2 diabetes. In fact, women who have had Gestational diabetes are at risk for developing full-blown Type 2 diabetes in the 5 to 10 years following childbirth.

The following can increase the risk of developing Gestational diabetes …

  • having an ethnic background – Hispanic, American-Indian, African, Asian, or Pacific Islander,
  • being overweight or obese before pregnancy,
  • having a family history of Type 2 diabetes,
  • being aged 25 or older,
  • having a history of Gestational diabetes in an earlier pregnancy,
  • having a history of giving birth to a baby over 9 pounds, or a stillbirth,
  • have had an abnormal blood sugar test result any time before becoming pregnant.