Twin Pregnancy Weight Gain and Weight Gain With Multiples

As the mother-to-be of multiples, you'll need to approach pregnancy weight gain differently than mothers of singletons. Gaining the recommended amount can help you avoid various issues during your pregnancy and after you give birth. It lowers the risk of your babies being born too small or too early and decreases the chance they'll need to stay in the neonatal intensive care unit (NICU). But just how much should you plan to gain?

It depends on a number of factors — including how many babies you're expecting and how much you weighed at the start of your pregnancy — and your practitioner will come up with recommendations specific to you. Here’s an overview of how much you should expect to gain until your twins or multiples arrive.

How much weight to gain in a twin pregnancy

One factor that plays into pregnancy weight gain recommendations is body mass index (BMI), a number calculated using your height and pre-pregnancy weight. (Use this National Institutes of Health BMI calculator to compute yours.)

BMI numbers correspond with different categories: 

• Underweight: <18.5
• Normal: 18.5–24.9
• Overweight: 25–29.9
• Obese: 30 or greater

Most practitioners advise women who start their twin pregnancy at a normal weight to gain 37 to 54 pounds. You should gain a little more if you were underweight (between 50 and 62 pounds) and a little less if you were overweight (between 31 and 50 pounds). If you have a body mass index of 30 or greater, you should gain between 25 and 42 pounds. 

That's nearly 50 percent more than what's recommended in a singleton pregnancy (talk about heavy lifting!). 

Gaining pregnancy weight can be challenging and sometimes scary, but it's only temporary. Dropping 30 pounds two weeks after delivering twins is not uncommon. All that excess fluid (extra blood volume, amniotic fluid and water weight) — not to mention the weight of your babies themselves — goes away rather quickly after birth.

Plus, studies have shown that among twin moms with appropriate weight gain, most women weigh only 5 to 8 pounds above their pre-pregnancy weight six to eight weeks after delivery.

How much weight to gain in a multiples pregnancy

If you’re pregnant with triplets or a higher order of multiples, your care team will come up with personalized recommendations for you. According to the American College of Obstetricians and Gynecologists (ACOG) and Institute of Medicine (IOM), there just isn’t enough data to issue guidelines for these types of pregnancies.

Twin pregnancy weight gain chart

Here's what to aim for depending on your starting weight. Expecting triplets or more? Take these numbers as more of a rough estimate. Your doctor will help you determine the right amount of weight gain for you.

How much weight to gain each trimester in a twin pregnancy

Does this mean that if your practitioner has advised you to gain 35 pounds, and a full-term twin pregnancy is 37 to 38 weeks, you should aim to gain about a pound a week? Ah, if only it were so simple.

The fact is that in a multiple pregnancy, each trimester presents its own challenges. Here's what they are, and what you should aim to gain:

First trimester

Your primary weight-gain challenge now is nausea. You have nearly double the hormones that make singleton expectant moms queasy, so it's quite possible that you'll have more intense morning sickness (and it's more likely it will last all day).

The good news: For some women, eating small amounts of food can actually help calm the stomach. If you are one of these lucky ones, just try to make the most healthful choices that your cravings (and your queasiness) will allow and aim to gain about a pound a week through the first trimester.

If you aren't so lucky, relax. You can catch up later. Just be sure to take your prenatal vitamin (ask your doctor about switching your vitamin if that makes you sick, too), sip fluids so you don't get dehydrated and tell your practitioner if you can't keep any food or liquid down.

Second trimester

If you're lucky, your nausea will have subsided around the 12-week mark. (For some, it's more like week 16 or even week 20.) Women pregnant with multiples should eat around 300 extra calories per baby per day, so now's your chance to really load up on the nutrition your babies need to grow.

If you gained no weight during the first trimester (or if you lost weight due to your nausea and vomiting) your practitioner may want you to gain 1.5 to 2 pounds per week during this period. (If you've been gaining steadily through the first trimester, aim for 1.5 pounds a week.)

If you need to catch up, it's time to supercharge your pregnancy diet with extra servings of protein, calcium and whole grains. Whole milk (with powdered milk mixed in, for an extra calcium kick), cottage cheese, beef and turkey are good options to get the nutrients you need.

Third trimester

Your goal now is to continue gaining 1.5 to 2 pounds per week through your seventh month. By 32 weeks, your twins may be four pounds each. (Think about it: That adds up to eight pounds of babies alone, which is as much baby weight as most moms of singletons ever have to carry to term.)

That doesn't leave much room for food, which is why heartburn and indigestion are all too common in the last stage of multiple pregnancies.

But don't give up on your healthy eating plan. Your babies are really growing now, and they need the nutrition a well-balanced diet provides.

Expect to gain a pound a week or less in the eighth month, and just a pound or so total during the ninth. (This makes more sense when you remember that most multiple pregnancies don't make it to 40 weeks.)

Weight gain with multiples is different from weight gain with a single baby, but it doesn't have to be complicated. If you're unsure of how much weight you should put on — or how to go about doing it — talk with your doctor. You may need to meet with dietitian and use nutritional supplementation for extra help. Your doctor will point you in the right direction and offer advice on how to gain in a steady way.