The Science of Conception

We're pretty sure you have an idea of how babies are made, at least the part that mom and dad put into the effort. But what about the science of conception? Here's what happens on the cellular scene. Ovulation Every month, one of mom's ovaries releases a mature egg into the adjacent fallopian tubes. Meanwhile, hormones thicken the uterine lining (endometrium) to create a comfy home for a fertilized egg —just in case. The egg sticks around the fallopian tube for 24 hours waiting for a sperm to show up. If he doesn't show, she gives up and makes her way out along with the uterine lining and you get a visit from Aunt Flo. If he does show up at the right time and place, whoo hoo! Fertilization is a serious possibility. Fertilization Sperm meets egg. Two crazy kids in love, the sperm penetrates the egg and they join to create a zygote, a cell that contains all of the genetic information needed to make a baby. The zygote takes off for the three-day honeymoon down the fallopian tube into the uterus. Implantation. Along the way, the zygote divides again and again, and becomes a solid ball of cells, then a hollow ball of cells (a blastocyst). Then the blastocyst attaches to the uterine lining. Hormones thicken up the uterine wall and produce a mucus plug to block the cervix. Then baby begins to grow and develop like crazy. Within three more weeks, baby's first nerve cells will have formed. By eight weeks, an ultrasound can usually detect the baby's heartbeat (such a sweet little woosh-woosh sound!). And you know what that means, a lot of poopy diapers in nine months!