For most expectant mothers, an 8lb baby is more than enough to deal with.
So spare a thought for Sarah Chiad, who carried two of them.
Her daughter and son, Hannah and Thomas, had a combined weight of 17lb 8oz, almost double the average for twins.
Hannah weighed 8lb 13oz and Thomas 8lb 11oz when they were born by caesarean section on January 11.
It means they are among the largest pairs of mixed-sex twins ever born in the UK.
Mrs Chiad had watched her waist grow to 57 inches during her pregnancy so she knew her babies would be big – just not that big.
She and her husband, Thomas, had endured three miscarriages in the past, including the loss of another set of twins.
She suffers from a rare blood-clotting disorder called Hughes syndrome or ‘sticky blood,’ which is one of the biggest causes of recurrent miscarriage. Clots form in the placenta, causing the pregnancy to fail.
When Mrs Chiad became pregnant for the first time she was expecting twins, but that pregnancy ended in a heartbreaking miscarriage.
After slimming down to 15 stone from 21 stone, Mrs Chiad then decided to try for a third baby. She said: ‘We ended up with two instead of one. It was a shock but a nice surprise.’
She found out she was expecting twins at a seven-week scan, and was again given medication to prevent her blood clotting.
The pregnancy went without a hitch and the twins were born at 37 weeks.
‘When I saw them for the first time they were big but normal babies. I didn’t realise they were anything unusual,’ she said.
The average twin is around 5lb so staff at Chesterfield Royal Hospital were stunned when they weighed Hannah and Thomas.
The babies, now five weeks old, are flourishing at home in Hasland, Derbyshire under the careful eye of their parents and older siblings.