What are warning signs at 39 weeks pregnant?

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.;

Third trimester · Pregnancy week by week

Week 39 of pregnancy

Q: How big is the baby at 39 weeks?

size of a small watermelon. The fetus is fully developed. Vernix is shed. Brain continues developing. Average fetal weight is ~3.3 kg (7.3 lbs), though there's wide variation.

Baby is the size of a small watermelon. About 20.00 inches, 3300g.

Week 39 is the optimal delivery window. Black women face higher rates of postpartum hemorrhage per ACOG Practice Bulletin 183 — the immediate postpartum period is the highest-risk window for severe morbidity. Source

What's happening with the baby

The fetus is fully developed. Vernix is shed. Brain continues developing. Average fetal weight is ~3.3 kg (7.3 lbs), though there's wide variation.

What's happening for you

Most women feel labor is imminent. Cervical dilation may begin. Some women have a 'bloody show' (mucus plug discharge). Many experience prodromal labor.

Common (normal) symptoms this week

Cervical dilation, bloody show, increased Braxton Hicks, prodromal labor, lightning crotch (pelvic nerve pain), nesting energy, sleep disturbance.

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

The final weeks and the immediate postpartum period are where Black-maternal-mortality cases cluster. Postpartum hemorrhage rates are 3 to 4 times higher in Black women per ACOG Practice Bulletin 183, and recognition is documented to be slower. If after delivery you soak a pad in under an hour, pass golf-ball-sized clots, feel lightheaded standing up, or your heart races at rest — go to the ED, not to your OB's office for an appointment. Postpartum preeclampsia can develop up to 6 weeks after birth and is repeatedly missed. The Serena Williams near-miss in 2017 wasn't an outlier — it was the median pattern.

What to do this week

Weekly visits. Confirm postpartum hemorrhage protocol with OB. Confirm postpartum visit at 1–3 weeks (not just 6 weeks). Confirm your support team (partner, doula, family) understands postpartum warning signs.

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References

ACOG Practice Bulletin 183 — Postpartum Hemorrhage
CDC Postpartum Maternal Mortality.

Last medically reviewed: April 25, 2026.

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