Third trimester · Pregnancy week by week
Week 33 of pregnancy
Baby is the size of a pineapple. About 17.20 inches, 1900g.
By week 33, antibody transfer from mother to fetus is significant. Black women have higher rates of cesarean delivery for comparable indications — preparing for delivery decisions matters now. Source
What's happening with the baby
The fetus's immune system is developing. Bones are hardening (except the skull, which stays flexible for delivery). Many fetuses are now in head-down position.
What's happening for you
Bump pressure increases. Many women experience pelvic-girdle pain. Heartburn may peak. Sleep is increasingly disturbed.
Common (normal) symptoms this week
Pelvic pain, heartburn, sleep disturbance, frequent urination, mild swelling, increased fatigue.
Call your OB or 911 if
- Severe headache that won't go away with acetaminophen — preeclampsia.
- Vision changes — blurred vision, light flashes, vision loss.
- Severe right-upper-quadrant pain — HELLP syndrome.
- Sudden swelling of face, hands, or feet.
- Reduced fetal movement — fewer than 10 kicks in 2 hours.
- Vaginal bleeding, fluid leakage, or persistent contractions.
- Severe shortness of breath at rest or chest pain.
- Fever over 100.4°F.
- Seizure — eclampsia, life-threatening.
Why this week matters for Black families
Group B Strep screening (35–37 weeks) is critical and Black women are screened at slightly lower rates per the CDC. If you haven't been swabbed by week 37, ask. Untreated GBS-positive delivery is a leading cause of neonatal sepsis. Also: confirm that your hospital is your delivery hospital, that your OB has privileges there, and that any complications protocol is in place. The 'doula in the room' decision matters most here — Black women with continuous doula support have measurably lower complication rates and lower rates of unwanted cesarean per multiple systematic reviews.
What to do this week
Begin weekly OB visits. Confirm GBS test scheduled. Discuss vaginal birth after cesarean (VBAC) options if applicable. Confirm doula will be in delivery room. Prepare older children for new sibling. Finalize hospital bag.
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References
- CDC NCHS Data Brief 389 — Cesarean Delivery Rates.
- ACOG Practice Bulletin 205 — VBAC.
Last medically reviewed: .
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