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

Your baby this week

Most of the lanugo is gone. Meconium is collecting in your baby's bowel and will fill the first diaper.

At 38 weeks your baby is still gaining weight, and most of the lanugo is gone. Meconium is collecting in the bowel and will be your baby's first poop. For you, waking often at night, feeling heavy and getting impatient are all natural. Agree with your provider on when to head to the hospital: usually when contractions are regular and getting closer together, if your water breaks, or if you have bleeding or severe pain. A contraction timer can help you track how often they come. If your provider has mentioned induction at 39 weeks, ask about the benefits and risks so you can decide together.

By the numbers

Week 38 covers days 266 to 272 counted from the first day of your last period, which is 95% of a 40-week pregnancy. About 14 days remain until a 40-week due date. Since last week, an average baby gains about 7.8 oz (220 g). By date of conception, your baby is about 36 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

You may feel heavy and wake up often at night. If your water breaks and the fluid is greenish, brownish or smells bad, tell your provider right away.

Tests and to-dos this week

Weekly checkups continue. Your provider may check your baby's position and talk with you about what labor might look like.

• Weekly visits · weeks 36–40 · visit

Signs of labor: when to go in

Labor usually starts with contractions that come at regular intervals and get longer, stronger and closer together; they don't ease when you rest or change position. Your water may break with a gush or a slow trickle, and you may notice a bloody show. Agree with your provider on when to call: many practices use the 5-1-1 rule of thumb (contractions about every 5 minutes, lasting about 1 minute, for 1 hour). Go in right away for bleeding, green or brown fluid, a severe headache, constant pain or fewer movements. A contraction timer helps you track the pattern without doing the math.

Contraction timer

Tips for the third trimester

• From 28 weeks, go to sleep on your side; if you wake on your back, just roll over.
• Pack your hospital bag and agree with your provider on when to head in.
• Call right away, even at night, if your baby moves less or differently.
• Know the signs of labor: regular, strengthening contractions, your water breaking or a bloody show.

Last week and next week

Last week (37): Your baby is practicing facial expressions like squinting and frowning.

Next week (39): The outer layer of skin has thickened.

Frequently asked questions