Any pregnant woman knows that their due date is calculated on a 40 week gestation period, however, once a pregnancy passes 37 weeks there is an increased risk for stillbirth. A new study is proving that while pregnancy past 37 weeks does present this increased risk for complications, allowing women to go to 41 weeks gestation isn't showing much more of a risk of stillbirth than women at 40 weeks, but after 41 weeks is a different story.

The study, led by Queen Mary University of London, looked at data from more than 15 million pregnancies in the UK, US, Denmark, and Norway. The study showed a total of 15,124,027 pregnancies, 17,830 stillbirths, and 2,348 newborn deaths and was published in the journal PLOS Medicine.

The study "is the largest study of its kind, and finally provides precise estimates of potential risks of stillbirth," study author Shakila Thangaratinam, from Queen Mary University in London, said. The study found that women at 41 weeks gestation have only a slightly greater risk of stillbirth than those at 40 weeks gestation, the equivalent to one additional stillbirth for every 1,449 pregnancies.

"While there is an additional risk of stillbirth at 41 weeks, compared to 40 weeks, it is small," Thangaratinam stated. "Women who prefer not to have medical interventions such as induction of labor may, therefore, acknowledge this small additional risk, and choose to wait until 41 weeks so that they have more time to go into labor naturally."

Thangaratinam also stated in a news release another shocking piece of information the study discovered. "We were surprised to see how much poorer pregnancy outcomes were for black women -- they were up to twice more likely to experience stillbirth than white women,"  she said. "Health care professionals need to take these added risks into account when developing care plans for these women."

Thangaratinam said the study is important because it can help expectant mothers and health care providers make educated choices when it comes to induction and delivery risks. "Now that we understand the extent to which stillbirth risks increase with each week of pregnancy, we should be incorporating this information in all discussions around delivery plans in pregnant women at term." The study did note that the highest risk for stillbirth occurs when a woman is allowed to gestate past 41 weeks, noting there is an 87% increase in risk at that point.

"Meanwhile, other women may prefer to have discussions with their healthcare providers on induction after 40 weeks. So this is all about helping women make informed decisions on timing of delivery," she added.

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