Researchers in Sweden have canceled a major study of women who have been pregnant for longer than 40 weeks, a full-term pregnancy after the deaths of six children, local media reported last month.

The study, which began in 2016, was suspended in October 2018 after five children died and a child was born and died days after birth, according to the British Daily Mail website.

The team wanted to compare the health outcomes of children and mothers in women at week 41 compared to women in week 42 and see if factors such as differences in personality and demography played any role.

It is customary in many Swedish hospitals not to incite a pregnant woman until 42 weeks, but these children are at risk because of low oxygen, being larger than usual, and suffering from low blood sugar.

"Moving forward with the study is morally wrong," the researchers said.

A full-term pregnancy is considered if the birth occurred after completing 40 weeks or 280 days.

Scientists agree there is little or no risk if a woman is delayed by a few days, or even a week after 40 weeks.

However, the risk of late delivery at 41 weeks and six days (late pregnancy) or to 42 weeks or more (subsequent pregnancy) is higher for the fetus.

They include low oxygen supply, low blood sugar and low levels of amniotic fluid, which can affect the baby's heart rate.