33 Weeks Pregnant

Baby’s Development

Your baby has grown to about 44 centimeters — roughly the size of a pineapple — and weighs approximately 1,900 grams, or about 4.2 pounds [1]. The skull bones remain flexible, connected by the soft spots (fontanelles) that allow your baby’s head to navigate the birth canal; these bones will not fully fuse until around 18 months of age. Your baby’s immune system is developing, and they are receiving antibodies from you — IgG crosses the placenta and provides passive immunity that will help protect your newborn during the first six months. The brain is forming neural connections at a remarkable pace. Body fat now makes up about 12 to 15 percent of your baby’s weight, and the skin is pink and smooth. The lungs continue producing more surfactant. Movement is still strong, though the quarters are getting tight, and your baby’s eyes can focus and track light. If born now, your baby’s survival rate is 95 percent or higher [2].

Body Changes

Your uterus is now about 13 centimeters above your navel, and a weight gain of 25 to 33 pounds by this point is typical. Your bump is large, and you may notice stretch marks, the linea nigra, melasma, more visible veins, and varicose veins. Your breasts may have grown by two or more cup sizes, and colostrum may leak occasionally. The “pregnancy mask” (melasma) can appear on your face, and swelling in your feet and ankles is common. Your heart rate may range from 80 to 100 beats per minute, and your center of gravity has shifted forward [2].

Tips for Week 33

• Address pelvic pressure with Kegels, side-sleeping, a support belt, pelvic tilts, and prenatal physical therapy. Avoid standing for long periods, and ask your provider for a PT referral if the pressure is severe.
• Finalize your pediatrician selection if you have not already — interview two or three candidates, and confirm their insurance acceptance, hospital affiliation, office hours, after-hours availability, and vaccination policy.
• Plan your postpartum support by deciding who will stay with you, what meals you will need, and what help you want. Communicate your boundaries clearly, and consider a postpartum doula (around $30 to $50 per hour in your area).
• Begin learning the signs of labor — how to tell contractions from Braxton Hicks, what a bloody show looks like, what it means when your water breaks, and when to call your OB. Practice the 5-1-1 rule: contractions 5 minutes apart, lasting 1 minute each, for 1 hour.

Things To Do (Checklist)

• Address pelvic pressure with Kegels, PT, or a support belt
• Finalize your pediatrician choice
• Plan your postpartum support
• Learn the signs of labor and the 5-1-1 rule
• Continue kick counting (aim for 10 movements in 2 hours daily)
• Position check; BP/urine monitoring

Frequently Asked Questions

Q: How do I know if it is really labor? A: True labor involves regular contractions following the 5-1-1 pattern (5 minutes apart, 1 minute long, for 1 hour), increasing intensity, contractions that do not stop with movement or rest, and sometimes a bloody show or water breaking. False labor tends to be irregular, does not increase in intensity, and stops when you move or change position. Call your OB when you hit the 5-1-1 threshold [1].

Q: I have carpal tunnel. When will it go away? A: Pregnancy-induced carpal tunnel usually resolves within 2 to 6 weeks after birth, as the swelling that causes it decreases. In the meantime, wrist splints can help, and surgery is rarely needed — often, time and healing are all that is required [2].

Q: Can I still exercise? A: Yes, with your provider’s okay. Walking, swimming, prenatal yoga, and light weights are all excellent choices. Avoid contact sports, lying flat on your back, and hot yoga. Listen to your body, and stop if you experience pain, contractions, or bleeding [1].

Sources

1. ACOG — How Your Fetus Grows During Pregnancy
2. Mayo Clinic — 33 Weeks Pregnant
3. What to Expect When You’re Expecting — Heidi Murkoff (Chapters 18-19: Third Trimester)