1st trimester · Week 12
12 weeks pregnant
Reflexes and a quieter miscarriage risk
Sucking and grasping reflexes are appearing. The uterus is becoming an abdominal organ. Statistically, the chance of miscarriage falls after a heartbeat is seen, but no week is a guarantee.
How big is your baby at 12 weeks?
- Length
- 5.4 cm
- Weight
- 14 g
- Size
- Olive
On average about 5.4 cm long and 14 g. Size comparison: Olive.
These are averages; every baby grows at their own pace.
How is your baby developing at 12 weeks?
The intestines are usually back in the abdomen. Vocal cords form. Bones are beginning to ossify. Crown–rump length is often about 5–6 cm. External genitalia are more defined but still easy to misread on a quick scan.
What changes in your body at 12 weeks?
Some people feel a first flicker of energy. Others remain exhausted. The waistband may need to loosen. Heartburn can start as the stomach is nudged.
Tips for this week
This is a common time for a dating or nuchal scan if not already done. Mention any bleeding, leaking fluid, or fever. If mood feels dark or panic is constant, tell someone — perinatal mental health support can start in the first trimester.
