During the first trimester you will:
Embryo implants in uterine lining
Heart begins to beat
Baby starts to form
Face, fingers, and toes begin to form.
Hair and fingernails are formed
Internal organs - kidneys, liver, lungs are forming and the heartbeat is getting stronger
The uterus is stretching
Baby is about the size of a pea
Baby grows to the size of a prune - about 1.5 inches long.
Your uterus has grown from the size of your fist to that of a grapefruit
Baby is moving more and begins to suck and have facial expressions
Key Hormones of the 1st Trimester
Estrogen - encourages growth, stimulates the uterus to stretch, begins the enlargement of milk ducts so your can nurse your baby, improves circulation, increases your sex drive, and can heighten emotions
Progesterone - iis key in building the uterine lining and inhibiting contractions so the baby can implant and the placenta can form well. It is also signalling the mom’s immune system that the baby is not a foreign invader. Progesterone also slows digestion down so you extract more nutrients from your food and causes tiredness. See article on Constipation.
Human chorionic gonadotropin (hCG) - stimulates the empty egg follicle to produce estrogen and progesterone until this function is taken over by the mom’s body.
During the first trimester:
Nausea and vomiting signal the beginning of morning sickness although frequently experienced in the morning it can continue into the day. The nausea brings with it loss of appetite. If you are not up to eating much, it’s okay. Eat as much nutritious food as your nausea allows - a hormone relaxin is changing the lining of your intestine to extract more nutrition from your food to help you and baby. Also, you may always feel full or bloated due to the slowdown in your digestion.
You may also have some spotting during the first 12 weeks. It can be caused as the baby implants into the uterus. This happens to 25-40% of women. Your doctor or midwife, with a vaginal ultrasound, can verify that everything is okay if you have concerns.
Toward the end of the first trimester your morning sickness should begin to fade. For some women, it will totally subside; for others, it will lessen as they move through the second trimester.
The end of the first trimester brings with it increased energy.
Julia Erickson, the founder of Aphrodite Project, is a wellness authority who uses food, meditation, and movement to create extraordinary health and wellness. Julia's practice is focused on helping women thrive and heal from chronic disease. She is also mother of seven.