1st trimester · Week 13
13 weeks pregnant
Stepping into the second trimester
Week 13 is often treated as the start of the second trimester. Fingerprints begin. Nausea frequently eases, though not for everyone.
How big is your baby at 13 weeks?
- Length
- 7.4 cm
- Weight
- 23 g
- Size
- Golden berry
On average about 7.4 cm long and 23 g. Size comparison: Golden berry.
These are averages; every baby grows at their own pace.
How is your baby developing at 13 weeks?
Vocal cords and a more proportional head-to-body ratio develop. Fine lanugo hair may start later this trimester. Average length is around 7 cm; weight is often near 20–25 g. Movements are larger but still cushioned.
What changes in your body at 13 weeks?
Appetite may rebound. The uterus can be felt just above the pubic bone in some people. Ligament twinges in the groin can begin as tissues stretch.
Tips for this week
Return to a more varied plate when food stays down: iron-rich foods, fruit, and fluids. Round-ligament pain is usually brief and one-sided; persistent or worsening pain needs assessment. Ask which foods to limit (unpasteurized dairy, undercooked meat, high-mercury fish).
