7 Weeks Pregnant: Baby Size, Symptoms and What to Do

Your baby this week

The brain is growing faster than anything else right now, which gives your baby a big forehead. Eyelids are starting to form, cartilage is developing inside the limb buds, and the arm buds are getting longer.

In week 7 the embryo roughly doubles in length. The umbilical cord forms, linking your baby to the placenta, and it will carry nutrients and oxygen for the months ahead. The three main parts of the brain are separating, the liver is making blood cells and the kidneys are starting to form. For you, this week is often the peak for nausea and a heightened sense of smell. If cooking smells bother you, cold foods tend to smell less. Peeing more often comes from your growing uterus and increased blood volume; if it burns or hurts, though, it could be a urinary tract infection, so get it checked. If you haven't yet, review the medicines and supplements you take and ask your provider which ones are fine to continue.

By the numbers

Week 7 covers days 49 to 55 counted from the first day of your last period, which is 18% of a 40-week pregnancy. About 231 days remain until a 40-week due date. By date of conception, your baby is about 5 weeks old.

Pregnancy is dated from the first day of your last period, so conception happens around week 2. Your due date is 280 days (40 weeks) from that day, and an early ultrasound may adjust it.

Your body

Your growing uterus presses on your bladder, so bathroom trips add up. Mild, period-like cramps can be normal, but get care right away for severe one-sided belly pain, shoulder pain, heavy bleeding or feeling faint.

Tests and to-dos this week

At your first visit, expect routine blood work, including your blood type and Rh factor, a blood count and infection screening such as syphilis, plus a urine test. Ask about genetic screening options early so you have time to decide.

• First prenatal visit · weeks 6–10 · visit

  Health history, physical exam and first-trimester labs. After that, visits are typically monthly until 28 weeks, every 2 weeks until 36 weeks, then weekly.

• First-trimester labs · weeks 6–13 · test

  Blood type and Rh factor, antibody screen, blood count, and infection screening including syphilis (ACOG recommends syphilis testing at the first visit, in the third trimester and at delivery).

Coming up: First-trimester screening (blood test + NT ultrasound) (from week 10). Full prenatal visit schedule

Tips for the first trimester

• Take 400 micrograms of folic acid a day; your provider may advise a higher dose if neural tube defects run in your family.
• Avoid alcohol, smoking, raw or undercooked meat, fish and eggs, and unpasteurized dairy.
• For nausea, try small, frequent meals and sipping fluids; call your provider if you can't keep anything down.
• Check every medicine and supplement you take with your provider or pharmacist before continuing.

Last week and next week

Last week (6): Your baby is about the size of a pea.

Next week (8): Your baby is starting to uncurl, and the head is lifting away from the chest.

Frequently asked questions