Start Pregnancy dating based on conception

Pregnancy dating based on conception

al., Fetal crown-rump length: reevaluation of relation to menstrual age (5-18 weeks) with high-resolution real-time US.

In order to use this calculator, you must know either the first day of the last menstrual period or the due date as calculated by your health provider.

The Eligibility Date provided using this calculator is the ONLY date we will accept (unless your pregnancy has been conceived by in vitro fertilization, and therefore you will know your actual date of conception).

Also, when providers all use the same LMP date, we are using one system that provides a standard convention.

Some women will deliver on their due date, others before, and others after.

The body is not on a clock counting down to delivery; natural variation will introduce uncertainty.

Health-care providers define the stage or length of pregnancy differently than many people might think. Logically, one might imagine we represent a pregnancy by how much time has elapsed since conception.

The conception calculator will give you a range of days in which conception may have occurred.