Is pregnancy weight gain safe during pregnancy?

What does the evidence say about pregnancy weight gain during pregnancy?

1. How much is normal comes down mostly to your BMI before pregnancy: roughly 28 to 40 pounds total if you started underweight, 25 to 35 pounds at a normal weight, 15 to 25 pounds if you started overweight, and 11 to 20 pounds with obesity. 1
2. Expecting twins raises the target: roughly 37 to 54 pounds total if you started at a normal weight, 31 to 50 pounds if you started overweight, and 25 to 42 pounds with obesity, since there isn't yet enough evidence to set a specific number for underweight women carrying twins. 2
3. Landing far outside your target range in either direction carries some risk: a review of more than 1.3 million pregnancies linked gaining well below the recommended range to smaller, earlier babies, and gaining well above it to larger babies and a higher chance of a cesarean birth. 3
4. Weight loss usually isn't the goal, even with obesity: guidance still points toward gaining 15 to 25 pounds if you're overweight or 11 to 20 pounds with obesity, and your provider sets the exact number that fits your health. 4
5. In twin pregnancies specifically, gaining far too little or far too much is tied to higher chances of preterm birth, cesarean delivery, and a baby that's unusually small or large for its gestational age, which is why twin pregnancies get closer, individualized weight tracking. 5

Is pregnancy weight gain safe in each trimester?

• First trimester. Expect only a modest gain now, roughly 1 to 4 pounds in total, since early changes come mostly from blood volume and tissue growth rather than fetal size. Some women gain very little or briefly lose weight because of nausea, which is common and usually not a concern as long as your provider knows about it.
• Second trimester. Gain usually picks up once appetite returns, typically averaging a couple of pounds a month, a bit faster if you started pregnancy underweight and slower if you started overweight or with obesity. Twin pregnancies are tracked against their own, higher targets.
• Third trimester. The second-trimester pace usually continues into the third trimester, though it can ease slightly in the final weeks for many women. Prenatal visits typically include a weight check against your BMI-based range, so your provider can flag and address any pattern running well above or below target before delivery.