First trimester · Week 12 of pregnancy

12 weeks pregnant: body, feeding, and care

Reflexes begin — the fetus can curl its toes and make sucking motions. Most major structures are formed; the end of the first trimester nears.

Body and care — week 12

Reflexes begin — the fetus can curl its toes and make sucking motions. Most major structures are formed; the end of the first trimester nears. 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

Week 12 questions

What is happening at 12 weeks pregnant?

Reflexes begin — the fetus can curl its toes and make sucking motions. Most major structures are formed; the end of the first trimester nears.

Which trimester is week 12?

Week 12 falls in the first trimester (weeks 1–13). See the first 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.