For pregnant women knowing how much weight gain is normal and healthy can be tricky. Now a new study suggests that women pregnant with twins who gained more weight than current guidelines that... See More
For pregnant women knowing how much weight gain is normal and healthy can be tricky. Now a new study suggests that women pregnant with twins who gained more weight than current guidelines that suggest. Were not actually at a higher risk of complications. Joining us to explain to ABC news medical contributor doctor top rates after -- good to -- things to be here. -- a little bit about this study it's rather surprising. OK so first thing we're talking about -- so everybody watching twins twins twins and twins according to the institute of medicine between 35 and about 55 pounds is weight gain from. This study and I've been thinking this the whole time is to tell twins to eat as much as possible. Again twins' twenty wins can eat for two. You really can eat and what they found was the more the woman gains the better off the twins were -- bigger. They were healthy air and because all the risk about having underweight babies I have friends crowded and mostly because -- and deliver early. The chance somebody reaching their due date the -- is is almost impossible they usually deliver about a month before. But many times even before -- -- -- one of his biggest possible and what they found was the more weight the women gained a better babies and the women didn't have. The classic side effects of increased weight gain such as blood pressure issues. And diabetes didn't oppressive does that mean if you're carrying twins cart -- car -- eat as much as you want. Every -- has been saying this -- guidelines I think we're wrong -- this study is proving it again. That's true and -- now let's try extra days it's out about a single that I don't get hate me after this assailant then. For normal weight the recommendations are 25. To 35 that's not very much just a very much and this is where -- hate comes in against me. I think that that's even too high on -- practicing obese. Would -- for a normal weight person. Twenty to 25 Max. Why so little you don't need to gain you don't need to eat for two Iowa safety for one point two so you only need just a little bit. Extra how many extra calories per day -- 200 or 300 which is not and you and I were talking like -- have -- -- happen. It's nothing it's almost eating the same. The -- just that touch touch more not disappointed -- Ever but Clinton and -- like. It's important in other countries where. Food is not so great or so what are the dangers are the risks to the baby -- for the mother if you gain too much weight they're actually to both so let's talk about the baby that's easy that to the baby. The more you eat again looking at the twins the bigger debate he got to get this baby out and it's a big big problem and a lot of us are already starting. A little overweight. So we start that we had more and we can have a really big base of their baby wise it's big baby getting the baby out through the birth canal. Increased chance of C section if you eat too much of a game too much weight in pregnancy and the maternal side gestational diabetes that those kind of on both sides of mother and the baby. And hypertension and then the ones that are adolescent as important but there -- veins knee -- back pain already you get the more -- carrying. Would this mass in the front the more you have to -- your pelvis backwards. -- -- -- and harder to lose the -- the morning games after that I actually have more way to get so you know it's interesting unlike a normal pregnancy. Maybe about seven pounds the percent just two pounds three pounds of blood to -- in the breast. And seven pounds overall kind of and you know where it goes. Here in in the yeah a fact that remains so -- This is certain amounts are gonna go with the delivery right center in the fluid and everything else think that what's left if you can minimize it when -- look in the mirror after baby. You won't cry as much support as it is a big body changed so we're talking about an average weight woman has but let's play you're already under way to Begin -- -- because under way you need to gain even more so basically you think about you need to get up to the point. Where you should have been when you got pregnant and -- that twenty to 25. And then overweight and obese that's interesting. Overweight you don't need to gain very much maybe about ten pounds the whole pregnancy. Now this is where the disagreement is in the obese I personally believe that you can actually lose weight because you can use those -- that you have stored up. The recommendations are about ten to fifteen pounds for so -- -- when she may be able to actually lose you actually may be able -- -- and have a safe pregnancy -- and avoid the hypertension. And the diabetes Associated Press your tips for pregnant women who do want to follow these guidelines they don't wanna intimate way to the -- president -- you right. I get craving and I'm not as active -- right used to be it's difficult to not tell it's it's it's tough not and. Many would have indicted their whole lives and finally they're pregnant right. This is at least leave video and well I don't have the right idea that I have a baby it's all about the baby back and I wanted militants have nobody can. They they start eating for two which is a big big mistake right -- Watch the cards the key thing in pregnancy the simple simple sugars are the ones that. The baby loves the as it goes right -- the outside and get a car -- at the beginning of pregnancy everyone gets a -- bright people hey whatever -- had just go with -- right but in that second and third -- if you could slow down -- is and I know people are gonna hate me. And think they're getting good nutrition. The -- is -- pure sugar if you want fruit eat fruit if you want. Vegetables don't juice and eat him. Bottom line is 300 calories a day expands -- -- -- -- not -- they could have.
This transcript has been automatically generated and may not be 100% accurate.