Can you really not know you're pregnant?

The condition, known as concealed pregnancy, is not as rare as it seems. Remember Peggy in Mad Men?

In an era when we are urged to seek medical help for every lump and bump before it is too late, it seems incredible that anyone could carry a baby through a full pregnancy without noticing. The British soldier who delivered a baby boy in the hospital at Camp Bastion this week astonished medics and herself. As a gunner in the Royal Artillery she claimed she had no inkling of her condition until developing stomach pains two days before she delivered.

The condition, known as concealed pregnancy, is not as rare as it seems. Remember Peggy in Mad Men? One study suggested as many as one in 150 women who got pregnant did not notice. Though difficult to ignore the stopped periods, painful breasts, nausea and weight gain associated with most pregnancies, these symptoms are not universal. Denial, too, plays a role.

Almost 200 soldiers have discovered they were pregnant at war since 2003. One can assume they did not plan to deliver on the front line – and thus had good reason to assume their thickening waists and occasional nausea were down to the army canteen.