Male female twins have sex

Female twins who shared a womb with a brother tend to get less education, earn less money, and have fewer children than girls who shared a womb with another girl, according to an analysis of hundreds of thousands of births over more than a decade. Researchers suspect the cause is testosterone exposure during fetal development, though the exact mechanism remains a mystery. Still, she cautions, a lot more work needs to be done to establish a causal link. Fraternal twins, in which each of two eggs is fertilized by a different sperm cell, occur in about four of every births.

'Extraordinarily Rare' Semi-Identical Twins Were Born in Australia

Can Identical Twins Be Different Sexes?

Is this really the case? And how does it work? Between week 8 and 24 of pregnancy, a male fetus is exposed to testosterone, whereas a female fetus is not. That is to say, it enhances the development of typically male traits. For example, increased aggression has been attributed to relatively high prenatal testosterone exposure. Because of ethical considerations direct measurements of prenatal testosterone in healthy human fetuses are carried out only rarely. Therefore, researchers have tried to find ways to estimate prenatal testosterone exposure using indirect measures.

Can Identical Twins Be Different Sexes?

Author contributions: V. In mammals, including humans, female fetuses that are exposed to testosterone from adjacent male fetuses in utero can have masculinized anatomy and behavior. However, the reproductive consequences of such prebirth sex-ratio effects for offspring and their implications for maternal fitness remain unexplored.
K ath and Chris Dent are both well-travelled and like keeping fit. They enjoy similar music and have compatible political and religious views. They are both 59, have great fun together and sound like a perfect match. There is no chance of them getting together, however, because they are twins. Being in their company is rather like spending time with a married couple who have been together for years.
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Comments
  •   Najas December 12, 2018
    I congratulate, your idea is magnificent
    +21 -0
  •   Kigakora June 6, 2019
    Yes, really. And I have faced it.
    +5 -13
 
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