A woman in her late 30s got an ovary donated from her twin sister and then started a successful pregnancy.

A 38-year-old woman from London has given birth to the world’s first baby conceived after a full ovary transplant.

The patient, who received an ovary donated by her identical twin sister, had a healthy daughter weighing 7lb 15oz today, delivered by Caesarean section.

The birth is the ninth reported worldwide after ovarian tissue was transplanted from one sister to another, but the first in which an entire ovary was used.

The woman who received the ovary went into menopause at age 15 for some reason. The ovary transplant is amazing. But also note the age of the woman. That the donor ovary could produce viable eggs really goes against the odds.

Dr. Sherman Silber, who carried out the ovary transplant at the Infertility Center in St. Louis Missouri, argues that young women should consider getting one of their ovaries removed and frozen for replacement when they get older.

I see no reason why this technique to prolong reproductive life should not be routine for all women who want it. The cancer patients who we have frozen ovaries for say they feel really lucky they had cancer, which is an odd thing to say. But they say 'I'm getting older and am not in a relationship and all my friends are worried about their biological clock. But I'm not worried because I've got a young ovary frozen'.

They wouldn't have done this if they were not confronted by the immediate situation of losing their fertility because of their cancer treatment but then they think about it a couple of years later and they are glad they did it because of the simple biological clock reasons.

Dr. Silber says this will extend the fertile period and also delay the symptoms of menopause.

What comes next? Once it becomes possible to grow ovaries from stem cells the logical next step will be for a woman to get some adult cells removed from her, genetically manipulated to become stem cells, and then further genetically manipulated with assorted improvements. Then the stem cells will get grown up into ovaries and implanted into her so she can have better babies than she'd have with her unenhanced genetic endowment.