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.
She was still oblivious to the blood problem when she later gave birth to 6lb 12oz Christopher, who is now nine. She said: ‘When he was delivered the placenta was full of clots and it was a miracle he survived.’ Mrs Chiad and her husband, a 41-year-old electronics engineer, tried for more children and two more miscarriages followed.
She was not given any tests in the UK, but when the family spent a period living in Austria she told a local doctor about her history and Hughes syndrome was ‘diagnosed straight away’.
The miscarriage risk is easily treated with blood-thinning drugs and as a result Rebekah was born, weighing 9lb 3oz. She is now five.
After slimming down to 15 stone from 21 stone, Mrs Chiad then decided to try for a third baby.
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.
Mrs Chiad said: ‘Rebekah and Christopher wanted one of each so they were delighted when they found out.’