At Open Arms Real Choices Clinic, we’re all about empowered education! We take great care to keep our staff and clients informed with honesty and transparency. We hope you enjoy our series on The Stages of Pregnancy. Let’s explore the first trimester.
The first trimester describes the period right after conception up until 12 weeks, or three months, gestation.
MONTH ONE – weeks 1 through 4
Within 24 hours, the fertilized egg (also known as the blastocyst) rapidly divides into multiple cells while remaining in the fallopian tube. After about 3 days, the blastocyst continues to divide and begins to pass down the fallopian tube into the uterus where it attaches to the endometrium.
Within 3 weeks, the blastocyst forms into a little ball commonly known as the embryo. During this time, a small sac forms around the growing embryo. This is the amniotic sac and it functions as a cushion for the embryo. The placenta also develops which serves as a lifeline from mother to baby. The mother is able to transfer nutrients to her baby and the baby is able to get rid of waste.
Many miraculous things are happening right from the moment of conception – before you even know you’re pregnant!
- A little face begins to form
- Large, dark circles as eyes begin to take shape
- The mouth, lower jaw, and throat develop
- Blood cells are taking shape and circulation begins. Fun Fact: The tiny, tiny heart tube beats up to 65 times a minute by the end of Week 4
- The baby’s first nerve cells form
- Size—1/4 inch long (that’s smaller than a grain of rice!)
MONTH 2 – weeks 5 through 8
After week 8, your baby is now called a fetus instead of an embryo. During this stage, exciting developments begin to take place. At about 6 weeks, the baby’s heartbeat can be detected.
- Little folds of skin begin taking shape as ears form on the sides of your baby’s head
- Tiny bulges begin to form into arms and legs including fingers and toes.
- The brain, spinal cord, and neural tissue form
- Bones begin replacing cartilage
- Sensory organs develop as well as the digestive tract
- Size—1 inch long
MONTH 3 – week 9 through 13
The baby is fully formed after month 3 of pregnancy. All of the extremities are present and will continue to grow and develop throughout the time in the womb. Though the sex organs begin to form, it can be difficult to determine the gender of the baby at this time.
- The fingers, toes, arms, and legs are fully developed as fingernails and toenails begin.
- The baby begins activity by opening and closing the fists and mouth.
- The beginning of the teeth form under the gums.
- Reproductive organs begin forming
- Size—4 inches long
The initial stages of fetal development and growth prove to be an exciting time for the mother. Even though there can be a lot of changes happening in the body and many trips to the bathroom due to morning sickness, your baby is here, your baby is growing, and he/she is on his/her way to becoming happier and healthier each week!