Surrogacy: Help and information.
She has suffered secondary infertility as well as twice acting as a surrogate, and says: "I don't think until you've experienced it you can know what it feels like not to be able to have a second child.
"The grief is heightened because after experiencing loving one child you know just what you are missing by not being able to create another." She's about to embark on her third surrogacy for a woman suffering from secondary infertility.
And she says: "Mums of one may feel enormous guilt that they can't provide a sibling for the first child, and worry that the only child's missing out on all that extra companionship and love.
"It can be like a knife in the heart when your child asks, 'When can I have a brother or sister?' Also, going to the school gate is jarring as you see other mums either pregnant with a second baby, with a little one in a pushchair, or notice children rush up to greet their baby brothers and sisters.
It's like a club that you feel you are excluded from." It's a club that Sarah Jessica Parker is determined to join..
Annie Casserley, from Streetly, gave birth daughter Emma and son-in-law Andrew to her own grandchild as a surrogate mother for Hattersley in 2005.