Women undergoing IVF are warned about sex

Couples will be cautioned against having unprotected sex while on a course of fertility treatment after an American women gave birth to quads, at least one of which was conceived naturally.

Couples will be cautioned against having unprotected sex while on a course of fertility treatment after an American women gave birth to quads, at least one of which was conceived naturally.

The woman's doctors believe it is the first time that conception from intercourse and from IVF has been reported in the same cycle, according to a report in the journal Human Reproduction.

Dr Amin Milki, of Stanford University, California, said the woman had two, five-day embryos transferred to her womb after fertilisation in a test tube. But a scan at seven weeks revealed she was carrying quads and she gave birth at 32 weeks to a boy and a girl with separate placentas and two girls with fused placentas.

DNA evidence and tests on the placentas showed the boy and the girl were fraternal twins, and the other two girls were identical twins derived from a fertilised egg which had split before implantation.

Dr Milki said: "The couple had intercourse just five days prior to the retrieval of eggs for IVF. It is just possible the identical twins could have resulted from one of the transferred embryos splitting.

But even if that were true at least one foetus would have been conceived spontaneously."

Because multiple pregnancies put mothers and babies at a higher health risk, Dr Milki said IVF patients should avoid unprotected sex as soon as the early days of ovarian stimulation were over.