First trimester · Week 12 of 40
12 weeks pregnant: the size of a lime
Reflexes develop: the baby can curl toes and make sucking movements.
Reviewed against ACOG, NHS and WHO guidance · Updated November 2026
Typical size
About 5.4 cm · 14 g
30% of the way to your due date
Your baby this week
Reflexes develop: the baby can curl toes and make sucking movements.
Your body this week
The risk of miscarriage drops significantly after this point. Your uterus rises above the pelvis.
Tip for week 12
Many parents have the dating (nuchal) scan around weeks 11–14.
Carry this guide in your pocket
Mamivaa is a free pregnancy app with a week-by-week tracker, vitamin and water reminders, a food scanner and a baby checklist.
Start freeThis guide offers general information and does not replace advice from your doctor or midwife. If something feels wrong, contact your provider or emergency services.