Week 42 of Pregnancy
Learn about your baby's development and what to expect at 42 weeks pregnant.
Baby's Size This Week
Baby Development at Week 42
- ● Your full-term baby is approximately 52.0 cm long and weighs about 3700g.
- ● Lung development is complete and all organ systems have been fully mature for weeks — the baby is ready for birth.
- ● Your baby's skull bones remain soft and flexible with open fontanelles, though the sutures may be firmer than at 40 weeks.
- ● The placenta is aging (grade III calcification is common at 42 weeks), which may reduce its ability to deliver optimal nutrition and oxygen to the baby.
- ● Amniotic fluid levels may be significantly reduced (oligohydramnios) at 42 weeks — low fluid is a key indicator that induction or delivery is necessary.
- ● The skin may appear dry, cracked, or peeling, and fingernails are long; lanugo has completely disappeared.
Your Body at Week 42
- ● You may experience significant pelvic pressure, lightning crotch, and difficulty walking as the baby remains deeply engaged in the pelvis.
- ● Signs of labor — regular contractions, water breaking, or bloody show — are expected at any moment; stay close to your birth facility.
- ● Your cervix is likely significantly effaced and dilated; your provider is monitoring closely and will have a clear induction plan in place.
- ● Extreme fatigue, emotional stress from prolonged waiting, and physical discomfort are all normal at 42 weeks; lean on your support network.
- ● Nesting may still be present but is often overtaken by exhaustion and impatience; rest is the priority now.
- ● Your provider will be closely managing your care this week — almost all providers recommend delivering by 42 weeks to reduce the risk of stillbirth and other complications.
Week 42 Checklist
- ☐ Attend all scheduled fetal monitoring appointments (NST and BPP) — at 42 weeks, these are done every 2–3 days or as directed by your provider.
- ☐ Confirm your induction of labor date and plan with your healthcare provider — most providers will not allow pregnancy to continue beyond 42 weeks.
- ☐ Rest as much as possible and stay nourished — labor may be induced within days and your body needs energy reserves.
- ☐ Know the immediate warning signs that require emergency care: no fetal movement for 2 hours, heavy vaginal bleeding, severe headache with vision changes, or high fever.
- ☐ Ensure your postpartum support is confirmed and on standby — your support person should be available at any hour.
- ☐ Review your birth plan one final time and confirm your provider and birth facility team have copies — induction may involve a longer labor process.
Frequently Asked Questions
What should I expect at 42 weeks pregnant?
At 42 weeks pregnant, you are two weeks past your due date and in the post-term period. Your baby is about the size of a Large pumpkin (52.0 cm) and has been mature for weeks. Induction of labor is typically recommended by this point by all major obstetric guidelines. Intensive fetal monitoring is ongoing, and your provider will have a clear delivery plan. Always consult your healthcare provider for personalized guidance.
How big is my baby at 42 weeks?
At week 42, your baby is approximately 52.0 cm in length and weighs around 3700g — roughly the size of a Large pumpkin. These measurements are averages based on WHO fetal growth charts; individual babies vary naturally in size.
Is it safe to wait past 42 weeks without being induced?
No — delivering after 42 weeks (post-term) carries significantly increased risks including placental insufficiency, oligohydramnios (low amniotic fluid), meconium aspiration, macrosomia, and a rising risk of stillbirth that doubles between 40 and 43 weeks. ACOG and WHO both recommend that delivery occur by 42 weeks 0 days. If you are approaching or past 42 weeks, your provider will strongly recommend induction. Declining induction at this stage carries serious medical risks.
What methods are used to induce labor at 42 weeks?
Induction methods depend on your cervical favorability (Bishop score). If the cervix is unfavorable (not yet soft or dilated), cervical ripening agents are used first — prostaglandin gels (dinoprostone), a Foley catheter balloon, or misoprostol. Once the cervix is favorable, Pitocin (synthetic oxytocin) is administered via IV to stimulate contractions. Artificial rupture of membranes (AROM/amniotomy) may also be used. The method and timeline are individualized by your provider based on your specific clinical situation.
What is oligohydramnios and why is it a concern at 42 weeks?
Oligohydramnios is a condition where amniotic fluid levels are lower than normal (AFI below 5 cm or deepest pocket below 2 cm on ultrasound). At 42 weeks, reduced amniotic fluid is a common finding because the baby's kidneys are producing less urine, fluid reabsorption has changed, and the post-mature placenta is less efficient. Low fluid reduces the cushioning around the baby and the umbilical cord, increasing the risk of cord compression during contractions. Oligohydramnios at term is a strong indication for prompt delivery.
Track Your Exact Pregnancy Week
Use our free Pregnancy Week Tracker to find out exactly how far along you are based on your last menstrual period or due date.
Track My Pregnancy →Sources
- ACOG
- WHO Fetal Growth Charts
- Mayo Clinic
Medical disclaimer: This content is for informational purposes only and is not intended as medical advice. Always consult a qualified healthcare provider for guidance specific to your pregnancy.