Doctors told her that she would be expecting a 3.6kg baby during an ultrasound scan eight months into her pregnancy.

But when Madam Nuraini Salleh finally popped on Jan 18, her baby girl, Mishel Aaricia, weighed nearly 4.2kg.

The 600g difference might seem small but it led to complications during the hour-long labour as Madam Nuraini says she had a 'difficult time pushing the baby out'.

Her firstborn's head had already started to crown - a term describing the moment when the baby's head emerges from the vagina - but was sucked back into the birth canal because the shoulders were too big.

'I was very stressed and in so much pain. I kept calling for the doctor to just take my baby out,' recalls the 27-year-old administration assistant.

She was surprised at how big her baby girl was when she finally saw her.

'People at the hospital would mistake her for a one-month-old baby when she was just three days old,' she says laughing.

'I think it was all the bubble tea, sweets and ice cream that I craved for and ate in the last month that made her gain so much weight.'

According to five obstetrics and gynaecology specialists LifeStyle interviewed, a big baby is considered to be one weighing more than 4kg.

At least 3 per cent of mothers in Singapore will give birth to a big baby. The average weight of an Asian baby is usually between 3.2kg and 3.5kg.

In a local case highlighted in a recently published book on the coroner's cases, a 5kg baby died due to shoulder dystocia, a labour complication when the baby gets stuck on its way out because the shoulders are too big to pass through the mother's pelvic bones.

According to the book, Coroner's Practice In Medical Cases, the baby girl also suffered spinal injuries from the complication.

Dr Tan Eng Kien, associate consultant at the Department of Obstetrics and Gynaecology at the National University Hospital, says such risks for big babies during natural birth are to be expected.

He also says that big babies might suffer other risks, including nerve or skeletal injuries and a lack of oxygen.

Heavier babies are more common now, say doctors.

The weight of newborn babies, says Dr Christopher Chong, who owns Chris Chong Women and Urogynae Clinic at Gleneagles Hospital, has increased by nearly 13 per cent compared to that of newborns 15 to 20 years ago.

He says: 'Women have better food, nutrition and supplements, so their babies tend to be larger.'

But he adds that there are other factors such as family genes and an onset of diabetes during pregnancy - a condition known as gestational diabetes - that might cause a baby to grow big.

He also says that 'eating a lot of sugary stuff', as in the case of Madam Nuraini, could contribute to the baby gaining weight.

The heaviest baby he ever delivered was nearly five years ago. The newborn was 4.87kg.

Such big babies are usually detected during regular antenatal check-ups through ultrasound and palpations, which is a clinical examination that crudely estimates the baby's weight according to the length of the pregnant woman's womb, say doctors.

But there is still room for an estimation error margin of up to 15 per cent in both methods, says Dr Tan Hak Koon, senior consultant at the Obstetrics and Gynaecology Department in Singapore General Hospital.

In cases of a possible big baby, mothers are usually prepped to decide whether they would like to have a natural birth or undergo a Caesarean operation.

'We usually encourage mothers with big babies, especially those delivering for the first time, to try natural birth which has lower risks to the mother,' says Dr Tan, who delivered his first baby 20 years ago.

His heaviest baby delivered was 5.2kg in the late 1990s.

He adds: 'Their labour process is closely monitored and a Caesarean birth is immediately carried out if there are any slight signs of complication for the mother or baby.'

For housewife Muslimah Moktar, 38, she is used to giving birth to big babies.

Three out of her nine children were big babies weighing between 4.1kg and 4.5kg at birth.

She expects her 10th, a baby boy due for delivery on March 2, to be a big one too.

Big babies, she says, cry much louder and drink a lot of milk. Carrying them around for long periods can also be tiring.

For her upcoming bundle of joy, she has been following her doctor's advice and keeping to a healthy diet, but Madam Muslimah says she 'can't help it that my babies are big'.

'Our family is big boned, so maybe that's why my babies are bigger.'

This article was first published in The Sunday Times on Feb 1, 2009.