When Are You REALLY Due? A New Test Can Better Predict Your Date

A due date is merely a rough estimate of when you'll be able to walk instead of waddle, eat a meal without having to pop Tums afterwards, and sleep on your stomach again. In fact, just 5 percent of women deliver on their due date, according to the American Academy of Pediatrics.

So wouldn't it be great if a simple test could predict when you were actually going to give birth? Well, according to a new study published in BJOG: An International Journal of Obstetrics and Gynecology, it can! Research suggests that measuring the cervix via transvaginal ultrasound reveals if a pregnant woman is likely to go into labor within the next week.

"This is something that is easily implementable tomorrow if people wanted," said study co-author Vincenzo Berghella, M.D., adding that the scan is completely safe.

Currently, doctors typically perform oh-so-comfortable manual checks to determine the length and softness of the cervix—an indicator that labor is imminent. But, as Dr. Berghella explains, "The beginning of changes in the cervix happen internally, not externally." An ultrasound looks at the entire cervical structure, and can detect more accurately if baby is ready to vacate.

The study included 735 pregnant women. Of the women whose cervices measured more than 1.18 inches (or 3 cm), less than half delivered within a week. But when the cervix was less than 0.4 inches (or 1 cm) long, 85 percent delivered within a week.

This new test has big implications for the future of labor and delivery. For moms, it may ease fear of the unknown, and help with planning work schedules and childcare. For doctors, knowing when patients are likely to deliver can help them staff the hospital more effectively, and make better medical decisions.

I wish this test had been around when I was expecting my third baby. Throughout the entire pregnancy, I'd felt convinced my due date was off. Especially at 35 weeks, when I didn't feel I could make it another day with that baby inside me, let alone another five weeks. Turns out I didn't have to; my daughter arrived at 37 weeks, 100 percent healthy. If only I'd known she wasn't too far away, I could have saved myself a lot of pain and suffering!

Melissa Willets is a writer/blogger and a mom. Follow her on Twitter (@Spitupnsuburbs), where she chronicles her love of exercising and drinking coffee, but never simultaneously.