Greater possibilities of twins
2006/05/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria
Dutch scientists investigate why more and more twins are born as their mother's age increases. So far it was thought to be due to a greater number of in vitro fertilizations, but now they have seen that there are also differences in natural pregnancies and that it is a matter of hormones.
Normally, in the follicles of the ovaries, a single egg arrives a month. It is released, can be fertilized for several hours and, if it is not fertile, it dies. As the age of the woman increases, the mechanism has more defects until menopause arrives, from that moment the ovaries stop disappearing.
But from the age of 35 and until menopause arrives, the organism produces more and more FSH hormones. This hormone influences the development of follicles and have now seen that the body seems to somehow balance the decline of the ovaries by producing more FSH. It seems that sometimes it produces too much and that is why two eggs are released in the same cycle. If both are fertilized, twins are formed.
To reach this conclusion, 959 cycles of 507 women have been analyzed. 105 women had more than one ovulation in the same cycle, of which only 5 were under 30 years, 45 were between 30 and 35 years old and 55 were over 35 years old.
