39 Weeks Pregnant

Baby’s Development

Fetus ~50.7 cm (small watermelon), weight ~3,300 g (7.3 lb) [1]. Full term — baby is ready for life outside. Placenta still nourishing baby; antibody transfer peaks now (IgG crosses placenta, provides passive immunity for first 6 months). Brain and lungs fully mature. Body fat ~15% of body. Skin: smooth, plump. Most babies in cephalic position. Survival rate: 99%+ [2].

Pregnancy Symptoms

Third trimester, full term. Symptoms: backache, heartburn, constipation, leg cramps, swelling, headaches, Braxton Hicks (intensifying). Uterus ~39 cm (fundal height). Lightening complete. Kicks distinct, possibly less frequent (less room). Round ligament pain, sciatica, pelvic pressure (intensifying). Weekly OB visits. Cervix may be effacing and dilating 1-3 cm. Bloody show, water breaking, regular contractions = labor [2].

Body Changes

Uterus ~39 cm fundal height. Weight gain: 30-38 lbs by week 39 typical. Bump large, “dropped.” Stretch marks, linea nigra, melasma, visible veins, varicose veins. Breasts 2+ cup sizes up, colostrum may leak. Possible “pregnancy mask” (melasma). Swelling in feet/ankles. Cervix: effacing, possibly dilating 1-3 cm [2].

Tips for Week 39

• Continue kick counting — 10 in 2 hrs daily. Less than 10 → eat, drink, lay on left, try again. 2nd low count → call OB.
• Address anxiety about labor — talk to provider, attend class, hire doula, read evidence-based birth stories, visualize the day.
• Finalize postpartum plan — who’s helping, meals, dog care (your dog!), work leave, sibling prep.
• Address pelvic pressure — Kegels, side-sleeping, support belt, prenatal PT.

Things To Do (Checklist)

• Continue kick counting (10 in 2 hrs daily)
• Address labor anxiety
• Finalize postpartum plan
• Address pelvic pressure
• Confirm hospital bag ready, route mapped
• Fetal position; cervix check; discuss induction if no labor by 41 wk

Frequently Asked Questions

Q: When will labor start? A: First-time moms: average 40 wk 5 days. 50% deliver by 40 wk 5 days, 75% by 41 wk 2 days. Don’t panic if “overdue” [1].

Q: Should I have an induction? A: Discuss with OB. ACOG: offer induction at 39 wk ( ARRIVE trial showed better outcomes). Standard practice: offer induction at 41 wk. Some providers offer at 39 wk [1].

Q: How long does labor last? A: First-time moms: 12-24 hrs (early labor 6-12 hrs, active labor 4-8 hrs, pushing 1-3 hrs). Subsequent: shorter [2].

For Dads

• Be the “5-1-1” expert — when contractions hit 5 min apart, 1 min long, 1 hr → call OB, drive to hospital. Time contractions (app: Full Term, Contraction Timer).
• Finalize logistics — go-bag by door, route mapped, parking plan, backup driver, child/pet care (your dog!), work calendar blocked.
• Practice labor support — counter-pressure, breathing cues, position changes, what to say/not say.
• Read The Expectant Father Ch. 37-38 — labor, your role, decisions in the moment.
• Pray for safe, healthy labor and delivery — the moment of meeting, the gift of life.

Sources

1. ACOG — How Your Fetus Grows During Pregnancy
2. Mayo Clinic — 39 Weeks Pregnant
3. What to Expect When You’re Expecting — Heidi Murkoff (Chapters 21-22: Labor Signs)