A new government study finds that the twin birth rate among women aged 35 to 39 has jumped by nearly a 100%. Since 1980 and among women over the age of forty. The rate has increased more than 200%. So... See More
A new government study finds that the twin birth rate among women aged 35 to 39 has jumped by nearly a 100%. Since 1980 and among women over the age of forty. The rate has increased more than 200%. So what's behind this trend ABC news metal contributor doctor -- -- Joins me now to explain the rise high -- great to see you need to be here so what is fueling all of these later stage mother. Fact number one and we all know it is it's going to be the fertility treatment. That's causing the majority. Of the twins because. What they do is they put into it putting three eggs a transfer from IDF. Hoping that one takes guess what a lot of times too will take and -- -- we have -- Thing about the -- -- is that so many people now it is assumed when they see all them other than last week and that -- was because of fertility -- but that's not all right I would say if you see -- -- -- mother of forty and above. That most of that is going to be fertility treatments -- -- -- -- thirty to forty. We will. That twins are more likely. So if you look at that naturally natural outright and I think the reason is is the brain is working a little bit harder. To send out the message for an -- to come out and because it has sent out that strong message. Two X com. Right and sell -- in huge numbers of there -- huge huge numbers of twins before it was one in 6156. That was in 1980 now one in thirty. And if you walk around any major metropolitan city like you do I'd like -- forget New York. But you're gonna see double strollers all over the place. Sounds good. It's there's no reluctance. Everyone -- I think a lot wouldn't want twins -- -- their hand oh my god that's great wins I'm done and over with -- lot of pre maturity. Lot of hypertension problems a lot -- of the mother a lot of props that they have to these babies are born less than five -- -- to remember that are they offering premiums as well. Was it a majority a lot of them are -- -- -- -- Anders premiums a lot of them are the very low birth. Race but now any of the -- is -- -- -- they can handle these that Mickey is advance that -- still previews and I have to be in in the key and handled intervention of the and got us now they're still danger there's still danger not so much danger that the -- community is really trying and -- they're pretty much there. You did see a lot less and actually the -- kind of slowed down a little -- just that this -- and. Because they're trying to put one and in -- to to a 34 so we are announcing a slight glendening. Forty age group you're gonna see it getting a little. Little bit but he has been so no more of these in planting 45 -- anti operating much over and. You know these are the moms and I think you're you're not that not the number of triplets and -- has announced. As they've gotten -- -- -- technology you can really fine -- very interesting setting that it operates thank you being here.
This transcript has been automatically generated and may not be 100% accurate.