(And as they say, a small condom might be uncomfortable, but nothing kills pleasure quite like an unexpected baby).
Finally, there is the wholly unexpected baby talk of "Slatland," the book's strangest and most unfettered story.
Some people do assume there is more to unexpected baby deaths than meets the eye, such as the result of postnatal depression or a similar syndrome, but I think that can cloud the issue.
So my parents, who were on a waiting list, got a call in the middle of the night asking: "We have an unexpected baby boy; do you want him?" They said: "Of course".
He was a cash-strapped high school teacher with two jobs, a bossy wife, a teenage son with cerebral palsy, an unexpected baby on the way, and a diagnosis of aggressive lung cancer.
AVERT, like many ambitious randomised controlled trials, took longer than planned to complete recruitment; our unexpected baby count added costs and delays, requiring grants from many funding agencies around the world (see acknowledgments).
Even with the most expert fetal medicine specialists scanning the fetus with ultrasound, and the increasing use of MRI, the unexpected still happens: babies with apparently fearsome lesions turn out to be relatively well, and babies with apparently minor issues can turn out to have lethal malformations.
A friend calls these unexpected additions "martini babies," yet I can't even blame alcohol.
"The study strengthens what previous research has shown, that co-sleeping is associated with a significant number of unexpected deaths of babies in the UK, but it also highlights the need for more research which examines the relationship between co-sleeping and other risk factors," said Francine Bates, FSID's chief executive.
