Blac Chyna is giving in to all her cravings. “My goal is to gain, like, 100 pounds this pregnancy,” the model announced on Snapchat in June. One month later, the 28-year-old fiancée of Rob Kardashian showed off her growing belly on Instagram with the caption: “Why should I watch my weight when I’m pregnant.” According to twin Ob-Gyns Idries and Jamil Abdur-Rahman, there are plenty of reasons.  

The amount of healthy weight gain during pregnancy varies. Dr. Idries encourages pregnant women to calculate their pre-pregnancy BMI (body mass index) and follow these guidelines:

Underweight (BMI less than 18.5) — 35 to 40 pounds recommended weight gain; for twins, 40 to 60 pounds.

Normal (BMI 18.5 to 24.9) — 25 to 35 pounds recommended weight gain; for twins, 35 to 55 pounds.

Overweight (BMI 25.0 to 29.9) — 15 to 20 pounds recommended weight gain; for twins, 30 to 50 pounds.

Obese (BMI 30 and higher) — 10 to 15 pounds recommended weight gain; for twins, 25 to 40 pounds.

But Dr. Idries stresses that you shouldn’t beat yourself up: “Mothers-to-be need to understand these guidelines are not the gospel, and it is never a good a good idea to obsess over a tenth of a pound.”

“Eating for two” is a dangerous myth. According to Dr. Idries, a pregnant woman only requires an additional 300 calories per day, which equates to a large, plain baked potato. 

The risks of excessive weight gain are numerous. Dr. Jamil warns that packing on too many pounds puts a mom at increased risk for gestational diabetes, preeclampsia (a condition characterized by high blood pressure) and large babies who must be delivered via C-section. “Approximately 50 percent of women who develop gestational diabetes will later in life develop overt or chronic lifelong diabetes,” the assistant professor of obstetrics and gynecology at Vista East Medical Center and Rosalind Franklin College of Medicine tells Us Weekly. Another side effect: “Moms with excessive weight gain are more likely to be unsuccessful in their attempts to breast-feed after delivery,” says Dr. Jamil. “It is thought that some of the hormonal changes that occur with obesity during pregnancy may ultimately play a role in this happening.”

Drs. Idries and Jamil Abdur-Rahman are on Twitter, Facebook and Instagram. They blog at Twin Doctors TV.

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