Is Pregnancy Dated from Conception?
Question
My dr. said the age of my baby from the length of it was nine weeks and five days. Is this from conception or from my last period? Nalini
Answer
Last Updated: December 11, 2014
Dear Nalini, That would be an important distinction, and you should ask your doctor which he was referring to. Actual fetal age, of course, would be dated from conception, but often they are referring to the number of weeks since your last menses. Ovulation is assumed to have occurred on day 14 (which it often is not), and so two weeks is added to the actual conception date. For instance, a baby would be due 38 weeks after conception, but full term is considered 40 weeks, becasue the pregnancy is dated from the last menses. So he may have meant you conceived almost ten weeks ago, but he (she?) probably meant you conceived almost eight weeks ago…
Hope that makes sense!
When a woman charts her cycles, with Natural Family Planning, a real advantage is being able to accurately identify the date of conception, based on ovulation, not just estimating conception based on the last menstrual period.
Sheila St. John
Hope that makes sense!
When a woman charts her cycles, with Natural Family Planning, a real advantage is being able to accurately identify the date of conception, based on ovulation, not just estimating conception based on the last menstrual period.
Sheila St. John
Answered By:
Sheila St. John
Sheila St. John is the Executive Director of the California Association of Natural Family Planning, coordinating the non-profit’s education and advocacy efforts throughout the state. Initially attracted to NFP as a healthy, effective method for planning families, drug, device and surgery free, her passion for NFP has grown over the last 42 years as she has journeyed with the over 900 couples she has personally instructed in its use, and been privileged to witness its role in overcoming infertility, women’s health, and the transformation that occurs in lives of men, women, and families, when we embrace God’s design for love and life.
