Due Date Calculations (how they work, and why they may have changed!)

We've been getting a lot of questions about how the due date in the app is calculated, and I've got an answer, straight from our engineers:

"The way that we initially calculate the gestation age on the app is actually slightly different than the way a health care provider calculates it.  Your doctor will set the start date of the pregnancy as the LMP and add 40 weeks to calculate the due date. But on our app,  we use the “Parikh’s Formula.” This is the expected date of delivery (EDD) = Last menstrual period (LMP) + 9 months + (Duration of previous cycles - 21 days). It's more complicated but also slightly more accurate when predicting the due date. We give users the option to edit the due date (and thus the gestational age) in the app. If you go to your  More page > Baby Health Profile and Due Date > click the due date, you can edit it to match what your doctor has said. But because the conception date is still an estimate (even for the doctor, they're estimating when it occurred), the gestational age of the pregnancy may differ by a few days."

Some people have also been asking about the difference in due dates between Glow and nurture. Glow currently uses the simple LMP calculation. So if you're curious about the difference between the two, you can see your Glow due date vs your nurture due date. We're looking at updating Glow to use the same formula as nurture.