Expected date of delivery

From Ganfyd

Jump to: navigation, search
LogoKeyPointsBox.pngIt is sometimes important to stress that in a biological process there may be considerable individual variation.

267 days (38 weeks) after conception. The conception date may be a few days after the known date of intercourse, but this gives an accurate date more often than is commonly thought. With an average menstrual cycle ovulation occurs on about day 14, so date of first day of the last period + 281 days.

Menstruation occurs 2 weeks after ovulation, so correct for women whose average cycle length is long or short on that basis.

Info bulb.png

Handy for mental calculation

  • By the various oddities of the calendar, first day of the last period plus 7 days minus 3 months