What Does
Due Date Mean?
A due date is an estimation of when a baby is most likely to be born. Typically, a pregnancy lasts 40 weeks from the day of conception, however, not many people are aware of the exact date they conceived.
Determining a due date plays a key role in helping doctors to determine how far along a pregnancy is, what tests need to be performed at specific milestones, and when to schedule check-ups to ensure that the baby is growing healthy.
FertilitySmarts Explains Due Date
There are several calculations which can help to give an approximate due date:
- Last menstrual period (LMP): Add 40 weeks or 280 days from the first day of your last period.
- Date of ovulation: 38 weeks or 266 days from the date of ovulation.
- IVF transfer: Date of embryo transfer plus 266 days, minus the age in days of the embryo at transfer.
- Ultrasound: A first-trimester sonogram, where measurements are taken of the fetus, is the most accurate way to determine the due date.
One study found that only 4% of women deliver at the 40-week due date, while an estimated 70% deliver within 10 days of the estimated due date. A person’s due date is a bit of a waiting game, and it is hard to correctly identify because the triggers for labor are not completely understood.