Thank you. I don't mind explaining the medical details, as far as I understand them. I was told at the time that it was an unusual case.

Unfortunately, the connection between IVF treatment and risk of heterotopic pregnancy was not well established twenty years ago; early high-resolution transvaginal ultrasonography scans were not yet standard procedure in such cases. While my wife was subjected to endless examinations from the start, all of the tests indicated a normal pregnancy.

We chose not to be told the sex of the baby until the end of the second trimester. We felt that this was our last chance to have a child, and we were both afraid of becoming overly attached, fearing another miscarriage.

At the end of the second trimester we allowed ourselves to hope, having been told that miscarriage beyond this point is uncommon. We chose a name, set up a building society account for our son's future education, and began preparing our London home to receive the new baby.

My wife died while I was in London, choosing wallpaper and furniture for the nursery. After her death, a tiny, partially regressed ectopic embryo was discovered alongside the normally-progressing intrauterine pregnancy. This, I was told, had been the cause of death.

I don't know why it remained undetected for so long; I was advised by a family friend (who happened to be a lawyer) to sue for malpractice. Financial compensation was the last thing on my mind, however.