The Early Weeks of Pregnancy
Before you even know you are pregnant, your body and your baby are doing amazing things. The sperm finally finds the egg, breaks through the outer shell and…conception!
The sperm’s nucleus will then merge with the egg’s to create new genetic material. Cells begin to divide and will divide into 16 identical cells over the next 3-4 days. By about the 5th to 8th day after conception, the little “blastocyst,” as its now called, burrows into the rich lining of your uterus. At this point everything needed for growth and development over the next 9 months is present. There is an inner cell mass, a fluid filled cavity, and an outer cell mass. As these cell masses continue to multiply, they then become the embryo, amniotic fluid, and placenta.
In order to prevent your body from thinking this blastocyst and everything with it is an intruder, and also to prevent the shedding of your uterine lining, the outer cell mass (what will become the placenta) begins producing the hormone, Human Chorionic Gonadotropin (HCG). Many think that the introduction of this hormone into the mother’s body at around the 4th week in her pregnancy is what sets off morning sickness, but no one is sure. What we do know is that HCG is the hormone that turns pregnancy tests positive. This is why you must wait until about a week after you’ve missed your period to take a pregnancy test and receive a reliable result. The level of HCG must be high enough to be detected by the test; otherwise, if you test too early, you could get a false negative.
Once you are 4 weeks along (so about the time you’ll find out you are pregnant) your baby enters what is called the “embryonic period.” This stage lasts until about 10-11 weeks gestation. It is during this time that all of your baby’s organs will begin to develop, and a few of them will even begin to function. By around the 6th week of your pregnancy, your baby’s heart will begin to beat anywhere from 100-160 times per minute. This sends blood through his body via his now-functioning circulatory system! His brain is also forming, now, as well as his muscles and bones.
By the time you are 8 weeks along he will have what look like little webbed fingers protruding from what will become his little arms and legs, and by around 9 weeks or so his eyes are fully formed, but he won’t be able to open his eyelids until about your 27th week. During this whole time the placenta has been developing also and now is going strong and bringing oxygen and nutrients to your baby as well as removing all his wastes back into your body, for disposal.
By about your 10th week of pregnancy, your baby enters the “fetal period”. The critical period of primary development is now behind him. This is the time to work on growing as well as fine tuning all the basics that were created in these first weeks of pregnancy.