What pregnancy week 39 means
Full term. “39 weeks pregnant” means 39 weeks have passed since the first day of the last menstrual period — the standard way pregnancy is dated. Conception usually happened about two weeks after that date, so the baby’s own age (fetal age) is roughly 37 weeks. Week 39 runs from 39 weeks 0 days to 39 weeks 6 days; on the following day the pregnancy is 40 weeks.
Your baby at 39 weeks
At 39 weeks a pregnancy is full term. The baby continues to put on fat, which helps with temperature control after birth, and the brain is still developing rapidly.
A common way to picture it: the baby is now about the size of a small watermelon — roughly about 50.7 cm and about 3.3 kg. These are averages; babies grow at different rates, and ultrasound measurements vary.
Your body at 39 weeks
Waiting can feel long at this stage. Light activity, rest and keeping a bag ready can help you feel prepared.
Care and appointments around week 39
If you have questions about induction or about what happens around your due date, this is a good week to ask at your appointment.
The timing of tests and appointments differs between countries and care providers. If anything worries you — such as bleeding, severe pain, fluid leaking, fever, or a change in your baby’s movements — contact your midwife, doctor or maternity unit straight away rather than waiting for your next appointment.
Week 39 in your pregnancy timeline
Week 39 is in the third trimester (weeks 28–40+) and in pregnancy month 9, which covers roughly weeks 36–40. You have reached full term.
| Pregnancy start (first day of last period) | |
|---|---|
| Estimated conception | |
| Estimated due date (40 weeks) |
Dates assume you are exactly 39 weeks 0 days today. For dates based on your own last period, use the calculator above or the main Pregnancy Calculator.
39 weeks pregnant in days and months
39 weeks is 273 days of pregnancy — 98% of a 40-week pregnancy. Counted in calendar months, 39 weeks is about 9.0 months, which is usually described as month 9 of pregnancy. Months are only a rough grouping; healthcare professionals almost always talk in weeks and days because they are more precise. See Pregnancy Month Calculator for how weeks map to months.