What is the truth behind Sarah Jessica Parker's use of a surrogate?

Imagine this. You are Sarah Jessica Parker. Although you do not look a day over 21, you are 44 years old. You have been married to Matthew Broderick for 12 years and have a six-year-old son. You would like to expand your family. Do you a) attempt to conceive naturally and resort to IVF if this doesn't work or b) draft in a "civilian" with no filming commitments to bear twins on your behalf. It's a no-brainer.

This week the Parker-Brodericks announced they are "happily anticipating the birth of their twin daughters later this summer with the generous help of a surrogate". Exactly how "generous" is the surrogate's help, though? Is she carrying her own children, which the Parker-Brodericks will adopt? Or is she playing host to the couple's genetic material? We don't know. But you can bet the surrogate was born well after the 1960s. According to Midland Fertility Services, the likelihood of an egg of a 45-year-old woman resulting in a viable pregnancy is less than 3%. (Leo Blair was indeed a miracle.)

What's fascinating here is the public announcement. The world of Hollywood post-40 conception is riddled with questionable fertility miracles. In recent years several well-known older actors have extolled the joys of having a baby. The same women have then been accused on the blogosphere of concealing their IVF treatment and/or their use of surrogates and, in particular, for being hazy on the subject of genetic material. The most aggressive donor advocates talk of "passing off" other people's children as their own and thereby stigmatising donor conception. In light of all this, SJP's annoucement feels a bit like half-disclosure.

The truth is, her work commitments may have heavily influenced this move: she is currently filming the sequel to the Sex and the City film, due for release in May 2010, and has another three films in pre-production. Not a great time to get pregnant.

Or is it? This whole thing would make a great SATC storyline. Carrie could make Samantha, Charlotte and Miranda fight it out to carry her twins, spurning them in favour of Stanford Blatch as the first male surrogate, before ultimately, self-sacrificingly, bearing them herself. Sob.