Third trimester · Week 33 of pregnancy
33 weeks pregnant: body, feeding, and care
The skull bones are still flexible and not yet fused, which helps with birth. The immune system is maturing.
Body and care — week 33
The skull bones are still flexible and not yet fused, which helps with birth. The immune system is maturing. Development notes on this page are general education summarized from ACOG patient-education material; they describe typical development, not your pregnancy specifically. Anatomy and growth are confirmed by your own provider and ultrasounds.
This week's checklist
- Note one body question — sleep, appetite, movement, comfort — and bring it to your next prenatal visit rather than searching it at 3 AM.
- Keep prenatal appointments on the schedule your provider sets; bring your questions list.
- Anything that worries you — bleeding, pain, reduced movement later in pregnancy — goes to your provider or urgent care first, never to a website.
Week 33 questions
What is happening at 33 weeks pregnant?
The skull bones are still flexible and not yet fused, which helps with birth. The immune system is maturing.
Which trimester is week 33?
Week 33 falls in the third trimester (weeks 28–42). See the third trimester hub.
How is a due date calculated?
A due date is typically estimated as 280 days (40 weeks) from the first day of the last menstrual period. It is an estimate — try the client-side due-date calculator; your provider's dating outranks it.
Educational information only — not medical advice. Every pregnancy and every baby develops on their own timeline. If you have any concern, talk to your obstetric provider or your baby's pediatrician.