A woman who is “genetically male” has had twins, after three years of pioneering treatment.

The new mother looks like a woman, but has 95% male chromosomes.

Though she has no ovaries and has never menstruated, doctors in India were able to help the woman conceive and give birth to the children through treatment that helped develop her uterus, which was described as infantile.

“This is something similar to a male delivering twins,” Sunil Jindal, the infertility specialist who administered the treatment, told the Times of India.

The woman herself did not know she had the condition, according to Sky News. She was “flabbergasted” when she was told but her husband was supportive.

The mother’s condition is known as XY gonadal dysgenesis. That means that the woman has external female characteristics, but doesn’t have functional gonads or ovaries. Those organs are usually necessary for reproduction, helping to create the eggs from which babies will grow.

Instead, doctors developed embryos using a donor egg and then placed that in the uterus, after it had been treated. That allowed the woman to become pregnant.

Doctors then had to help the woman carry the pregnancy “in a body not designed for it”, as Anshu Jindal, medical director at the hospital that delivered the babies, described it to the Times of India.

The two babies, one boy and one girl, were delivered through caesarean section.