Proud parents Thomas and Sarah Chiad had an extra big surprise with the birth of their twins.
The bouncing babies’ combined weight tipped the scales at almost 18lbs - making them one of the heaviest pairs of mixed-sex twins in the country.
Sarah, 38, had an inkling the twins she was expecting might be bigger than normal when her bump measured 57 inches.
But it did not stop the mum-of-four who was still decorating the tots’ bedroom at 32 weeks pregnant.
Following a Caesarean section at Chesterfield Royal Hospital Hannah arrived weighing a thumping 8lb 13 and Thomas weighing 8lb 11, on January 12.
Sarah, of St Paul’s Avenue in Hasland, said: “I knew they were going to be big but didn’t expect this.
“I didn’t realise what weights they were until I looked at their cards on their cribs. It was a big surprise.”
She added: “My health visitor said in 20 years she has never known such big twins.”
Sarah, a supply teacher at Hasland Infants School and Thomas, 41, an electrical engineer, are already parents to Christopher, nine and five-year-old Rebekah.
The couple decided to try for another baby after Sarah lost six stone - going down from 21 stone to 15.
“After losing the weight we thought we’d try for another but ended up with two. It was a shock but a nice surprise,” said Sarah.
Sarah also suffers from a rare blood disorder called Hughes’ syndrome which makes the blood more likely to clot than normal.
It can also cut off the blood supply to the placenta so on discovering she was pregnant she had to undergo blood tests.
Christopher weighed 6lb 12 when he was born and Rebekah, 9lbs 3 but the average twin weighs around 5lb so Sarah said she had expected them to be much smaller.
She added: “Rebekah and Christopher wanted one of each so they were delighted when they found out.
“They are getting on very well and are good babies. They already look so different and have different personalities.
“Thomas is very chilled out and Hannah is a bit more fussy.”
In 2007 a woman gave birth to the heaviest mixed-sex twins born in the UK, who weighed a combined 18lb 12oz.