Fetal Development Day 1: When conception (fertilization) occurs, the baby's features, including sex, hair and eye color, have already been determined. 9 Weeks LMP:  (Last Menstral Period) 7 weeks after conception At this age, the baby's heart has been beating for one month and fingers and toes are developed. An embryo at this stage responds to touch. It can move although it is too tiny to be felt by the mother. 10 Weeks LMP: 8 weeks after conception At 10 weeks, the baby hiccups and reacts to loud noises. 16 Weeks LMP: 14 weeks after conception At 16 weeks, the baby's gender can be determined by ultrasound. 22 Weeks LMP: 20 weeks after conception At this age, the baby's eyelashes can be seen and the lungs are developing.

Pregnancy Definitions Cervix: The bottom opening to the uterus. Embryo: Human life at an early development stage with its own unique DNA. Conception: The point at which a male sperm and the female egg join and a new human embryo begins; also called fertilization. Fetus: A developing unborn baby with an observable human structure. Full Term Pregnancy: The stage at about 40 weeks after last menstrual period or 38 weeks after conception when the unborn baby is ready for birth. Last Menstrual Period (LMP): The date when a woman started her last menstrual period before conception. This is the point in time from which the pregnancy and the age of the unborn baby are measured. Trimester: An interval of three months used to measure three successive stages of pregnancy; first trimester, second trimester, and third trimester. Uterus: The muscular female organ that contains the developing unborn baby.