Week 39 of pregnancy
Your baby this week
About 3403 g (estimated weight; Source: WHO fetal growth charts (Kiserud et al., PLoS Med 2017)) — about as heavy as a small tarbooz (watermelon) (Source: ICAR-Central Institute for Arid Horticulture (BMC Plant Biol 2025) 'Harnessing genetic variation in watermelon...', Table 1: parental line AHW/BR-22 fruit weight 2600-2900 g). Every baby grows a little differently.
How your baby is developing
- The baby is typically considered full term this week; brain and lung development are still finishing.ACOG
How you may feel
- Full term; signs that labor may be approaching — nesting, increasing contractions, pelvic pressure — can become more noticeable, though timing varies widely.ACOG
Nutrition this week
When to reach out
- Heavy vaginal bleeding or passing clots.ACOG
- Severe or persistent abdominal or pelvic pain.ACOG
- Severe, persistent nausea or vomiting that prevents keeping any fluids down (possible hyperemesis gravidarum).NHS
- Fever of 38°C (100.4°F) or higher, or chills.WHO
- Severe dizziness, fainting, or a racing/irregular heartbeat.NHS
- Pain or burning when urinating (possible urinary tract infection).NHS
- A severe or persistent headache that doesn't improve.ACOG
- Sudden swelling of the face, hands, or feet.ACOG
- Visual disturbances — blurring, flashing lights, or spots.ACOG
- Regular contractions, pelvic pressure, or low back pain before 37 weeks (possible signs of preterm labor).ACOG
- Fluid leaking or gushing from the vagina (possible ruptured membranes).NHS
- Persistent pain in the upper abdomen, especially under the ribs on the right side.ACOG
- A noticeable reduction in the baby's usual movements, or no movement felt — contact your midwife or doctor promptly rather than waiting; do not wait until the next appointment.ACOG
- Regular, painful contractions before 37 weeks, or any contraction pattern that concerns you near term.ACOG
- Waters breaking, or blood-stained ('bloody show') discharge — a normal sign labor may be starting at term, but call your midwife or doctor to be checked.NHS
These apply to this week specifically. See the full list of urgent warning signs the CDC publishes for pregnancy and the year after birth.
Part of the Third trimester (weeks 28–42).
Educational reference only — not medical advice. Typical/average figures; every pregnancy differs. Always consult your doctor or midwife. Seek urgent care for any warning sign.