Third trimester
37 weeks pregnant
Baby is about the size of a bunch of Swiss chard.
Week 37 of 40 · in your third trimester · Updated
Your baby this week
Officially 'early term' — baby is essentially ready to meet you.
- Baby is now considered 'early term' — fully ready for life outside.
- Practice breathing intensifies. Lungs are functioning fully.
- Baby may have hair (or be bald) — both are normal at birth.
Your body this week
Watch for signs of labor: lower back pain, contractions, water breaking, mucus plug.
- Watch for signs of labor: regular contractions that get stronger, lower back pain, water breaking (gush or trickle), losing the mucus plug, bloody show.
- Call your provider if contractions are every 5 minutes for an hour, water breaks, or there's any bleeding.
- Some women lose the mucus plug — a thick, sometimes blood-tinged discharge. Labor could start anywhere from hours to weeks later.
Common symptoms
- Sense of nesting (sudden urge to clean/organize)
- Loose stools (body prepping)
- Pelvic pressure
- Mucus plug
- Strong contractions
Things to do this week
- Familiarize yourself with hospital labor & delivery process
- Decide who's allowed in the delivery room
- Charge all phones/cameras
For partners this week
Ready when baby is
- Know when to call: water breaking, any bleeding, or regular contractions getting stronger.
- Agree on who'll be at the birth and who gets the first update.
Typical visits around this week
Based on a typical schedule in Ontario. Your doctor or midwife sets the actual timing.
Group B strep swab
Weeks 35–37
A quick vaginal and rectal swab, usually between 35 and 37 weeks, to check for group B strep bacteria. If it's positive, you'll be offered IV antibiotics during labour or if your water breaks.
Questions to ask →Questions to ask ↑
- Can I do the swab myself?
- How will I find out the result?
- If it's positive, what happens when I go into labour?
Weekly check-ups
Weeks 36–40
From about 36 weeks, visits are usually weekly until birth. Your provider checks the baby's position and your health, and goes over signs of labour and when to come in.
Questions to ask →Questions to ask ↑
- Is the baby head-down?
- When exactly should we call or head to the hospital?
- What's the plan if my water breaks before contractions start?
- What happens if I go past my due date?
Coming up
Past your due date
Weeks 40–42
If the baby hasn't arrived by your due date, your provider may ask you to track movements daily and may suggest extra checks, like a non-stress test of the baby's heart rate or an ultrasound of the fluid around the baby. Induction is usually discussed around 41 to 42 weeks.
Questions to ask →Questions to ask ↑
- How often will the baby be checked from here?
- When would you recommend an induction, and how does it work?
- What are our choices if we'd rather wait a little longer?
- What changes mean we should come in right away?
A flu shot and a COVID-19 vaccine are recommended at any stage of pregnancy. The flu shot is given during flu season, so the timing depends on when you're pregnant.
When to call your doctor or midwife
Bleeding, fluid leaking, a bad headache or vision changes, or baby moving less than usual all need a call. See the warning signs and who to call →
Follow your pregnancy week by week in MyBabyBase.
A due-date countdown, a mood and symptom journal, appointments, and a safe place for your documents — all in one hub.
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Further reading from health authorities
- Pregnancy — Government of Canada (Public Health Agency of Canada)
- Your pregnancy — Pregnancy Info, from the Society of Obstetricians and Gynaecologists of Canada (SOGC)
- Week-by-week guide to pregnancy — NHS (UK)
- Pregnancy — American College of Obstetricians and Gynecologists (ACOG)