Pregnancy Guide - My Pregnancy Development

Calculating the day your baby begins to develop and keeping track of your pregnancy dates can be a challenge. The development of pregnancy is counted from the first day of the woman’s last normal period, even though the development of the fetus does not begin until conception. Pregnancy is calculated from this day because each time a woman has a period, her body is preparing for pregnancy.

The following information is used as a general guide for healthy pregnancy development, although development may vary due to the mother’s health or a miscalculation of ovulation. Gestational age is the age of the pregnancy from the last normal menstrual period (LMP), and fetal age is the actual age of the growing baby.

Most references to pregnancy are usually in gestational age rather than fetal age development, but we have included both so that it is clear what stage development is at. Measurements will be given in total length from head to toe, but each pregnancy can differ in weight and length measurements, and these are just a general guideline.