Gestational Age: Weeks 1 &2

Shortly after your menstrual period ends, your body begins getting ready for ovulation. Because every woman’s body is different, ovulation can occur anywhere from 11-21 days after the first day of your last period. During intercourse, the male will release hundreds of millions of sperm into the vagina. The sperm will move through the cervix and up into the fallopian tubes where your egg is waiting. If just one sperm is able to reach the egg and penetrate it, conception will occur. The sperm and egg fuse to create a new life. This new being has a set of 46 chromosomes and is called a zygote. The fertilized egg will start dividing and begin travel through the fallopian tubes towards your uterus. At this stage the dividing egg is called a morula. As it continues to divide and make its way to the placenta it is called a blastocyst. Six to twelve days after conception, the blastocyst will arrive in the uterus and imbed itself in the uterine lining. This begins the embryonic stage of development.

Gestational Age: Week 3 (Fetal Age - Week 1)

The embryo will now begin to undergo an incredible amount of growth, dividing and forming into a human. Fetal development begins the heart, brain, spinal cord, and gastrointestinal tract.

Gestational Age: Weeks 4 & 5 (Fetal Age - Weeks 2 & 3)

Your body has begun to form a placenta, which will provide your baby the nourishment it needs while it develops. The placenta produces some important hormones called hCG, which pregnancy tests detect for in determining if you are pregnant.

The embryo’s heart is now beating with a steady rhythm. Arm and leg buds have begun to form, but are not yet recognizable. And the beginning of eyes and ears are now distinguishable. At the end of this week, the embryo will be about ∫ of an inch long.

Gestational Age: Week 6 (Fetal Age - Week 4)

Your baby will start to form it’s lungs, nose , jaw, and palate this week. It will also continue its limb development, with webbed structure on it’s hand and feet buds that will become it’s fingers and toes. And the brain continues forming its complex parts. The embryo will be about a _ inch long now. Your baby’s heartbeat can be heard now with a vaginal ultrasound.

Gestational Age: Week 7 (Fetal Age - Week 5)

By now, the embryo has begun to form every essential organ. Hair and nipple follicles have begun to form, as have eyelids and a tongue. As the embryo’s trunk starts to straighten out, it’s elbows and toes can be seen more clearly. Your baby is looking more like a little human every day, but still does not weigh more than an aspirin.

Gestational Age: Week 8 (Fetal Age - Week 6)

Your baby is developing it’s ears both externally and internally. It now has everything that an adult human has. Its muscles can contract and its bones have started to form. The embryo’s face continues to mature, and it has developed eyelids. At the end of this week, your baby will be about 1 inch long, about the size of a bean. This week ends the embryonic stage of development. Your baby will now begin the fetal period and is called a fetus.

Gestational Age: Week 9 - 13 (Fetal Age - Weeks 7 -11)

By this time, your baby will have formed its male or female genitalia, although you can not see it clearly with an ultrasound yet. Its head is almost half of its entire size. The fetus can move it’s hands to make a fist, and the first sign of teeth have developed as tiny buds in it’s mouth. Your baby’s eyelids will close now and not open again until the 28^th week of gestation. The fetus weighs around an ounce and is about 3 inches long.