SuperWomen: MOM of twins may live longer

Having two babies at once is associated to a longer life, according to a new study. But it is not because doubling on dirty diapers increases the duration of life; Instead, the mothers of twins are physically stronger in the first place.

Capture one: research published today (May 10) in the case in the journal of the Royal Society B, based on a population of "natural fertility" women in Utah for the 19th century, the results may not apply in the today of the world of fertilization in vitro (IVF).

However, the findings suggest that rather than being a reproduction accident which drains energy and nutrients, twin mom may be an evolutionary adaptation in which mothers take the chance to spend on the double their genes.

"We expected the exact opposite," researcher study Shannen Robson of the University of Utah told LiveScience. "We expected that since most humans have a baby at the time, having both would be really heavy...". [Twins] are an identifier of these women who are physically exceptional and remarkable people. ?

Natural fertility

Identical twins, created when an embryo is divided into two development, appear more or less randomly. But the twins, which develops from two eggs separate released and fertilized at the same time, shows some two heritability models - they ran in families - and the influence of the environment. Not including the twins designed from IVF, account of twins for every 1,000 births in Asia 6, 10 to 20 of every 1,000 births in Europe and the United States and 40 with every 1,000 births in Africa.

To look at before matching techniques of reproduction and reliable contraception, the team used the Utah Population Database, a huge genealogical record of the residents of Utah dating from the beginning of the 19th century. The database, they taken from the family archives of women who were born between 1807 and 1899 and who lived up to at least 50, so that they have experienced their full range of child-bearing. Excluded widows and wives in the polygamous families to ensure that they were comparing similar women. [History and the future of birth control]

The result was a database of women 58,786, 4,603, who had at least a set of twins. The researchers compared the Moms of twins with the mothers of the singletons, for differences in life expectancy, the number of children, the time between pregnancies and the length of fertility, all measures of health.

Double the pleasure

Flight from the hypothesis that double pregnancy Vienna undermine the strength of women, the researchers found that MOM of twins beat moms only singletons on all measures. They live longer, had more long durations of reproductive life, required less time to recover between pregnancies and had more children together. The mother of twins born before 1870 had averaged 1.9 more children that the mothers of singletons in their age group and Moms in the post-1870 Group had 2.3 children more than their counterparts of mom singleton.

Because the twins have a higher risk of death than singletons, researchers have adjusted this conclusion by the rate of infant mortality, assuming that a MOM of twins may have more babies soon after the death of a child. After this adjustment, moms of twins still out before him, having 1.24 to 1.56 babies more than singleton only moms. That outweighs the effect "plus one" you get to have twins, said Robson.

The results vary with time, even if women pioneers in Utah pre-1870 had worse than born women medical care after. It is difficult to compare the data of the 19th century to our days however, Robson said. IVF has increased the number of twins. And other factors have also changed: women have less overall pregnancies now than women in the 19th century in Utah, so their overall chances of a spontaneous twin pregnancy are lower. A 2001 study of women in rural areas in the Gambia, however, found that mothers of twins had better reproductive health that mothers of only singletons. [Read: 5 myths about fertility treatment]

Robson and his colleagues now hope to watch the twins of women of Utah, to see how they behaved given the twins are more likely to be premature and have health problems. They also hope to look more closely at the supermoms which birth of twins.

"By their identification, we can then look at other aspects of what is on them that makes them healthier, live longer and have babies at a faster pace than everyone in the population," Robson said.

You can follow LiveScience senior editor Stephanie Pappas on Twitter @ sipappas. Follow LiveScience to the latest science and discoveries on Twitter @ livescience and on Facebook.

BYU researchers hope twins unlocks the mysteries of AIDS (AP)

SALT LAKE CITY - Brigham Young University researchers strive to unlock some of the mysteries surrounding the viruses that cause AIDS with a trio of studies dealing with unusual cases involving a set of twins, a vaccine failed and a protein "stop sign".

The identical baby twins received a contaminated transfusion and became HIV positive two years ago.

Now, one of the twins has an immune system of normal and a fairly good health, while the other boy is five years behind him on the graph of the growth and has experienced a number of complications.

That provocative difference has become the basis of one of these studies, researchers led by the President of Department Biology BYU Keith Crandall trying to understand how the virus has changed in each twin. They were joined in the study by scientists at the National Cancer Institute.

Crandall said there are competing theories on the differences in their clinical results. A theory is that natural selection drives, so the results should be similar. The other holds that random genetics plays a role, and it cannot therefore predict.

A second study focuses on a Thailand anti-HIV vaccine, scientists are trying to develop that proved to be ineffective. Crandall said that they hope to samples from this case will help them learn more about how the virus has evolved and if vaccination to protect themselves against HIV is promising.

"I think that the community of HIV is still divided in terms of how to continue treatment against HIV infection," Crandall told the Deseret News.

There is a strong camp who thinks that the vaccine is still the way to go. We need to do more intelligent design of vaccine, "carefully in view of everything they have learned in other attempts to create a vaccine that works."

"Others say nothing," he said. "The focus must be on pharmacotherapy." "But the virus tends to hide in places where drugs cannot get their".

The final study is led by Greg Burton, President of the BYU Department of chemistry and Biochemistry and Xueyuan Zho, student in the Department of the University of Colorado Health Sciences. They confirmed a previous report a natural protein prevents HIV from multiplying. But they have gone further to explain how the protein, not only what is happening.

"The importance of this study is that we have progressed from previous research." "Burton effect was known, but we have shown the mechanism," said.