25 WEEKS PREGNANT
The fetus starts to build up layers of fat
Baby this week: about 31.8 cm — head to heel · about 660 g
≈ 31.8 cm — about the size of a head of cauliflower
Illustration enlarged for clarity — the amber marker shows true relative size
Your baby this week
- Fat is accumulating under the skin, which will gradually smooth out the wrinkled look
- Capillaries are forming and filling with blood, giving the skin a pinker tone
- The nostrils, previously plugged, begin to open
- Hand movements are becoming more coordinated
Your body this week
- Braxton Hicks contractions may become more noticeable, though they should be painless and irregular
- Sleep can become harder to find a comfortable position for as the belly grows
- Braxton Hicks practice contractions are irregular and painless — contractions that become regular, painful, or stronger before 37 weeks, any fluid leak, or bleeding mean contacting your provider immediately.
This week's tip: A pregnancy pillow or extra cushions can make side-sleeping more comfortable as the bump gets bigger.
Want the bigger picture — organ development, nutrition, scans and warning signs for this stage? See month 6: Settling into the bump.
Sizes and milestones are typical ranges — every pregnancy runs on its own clock. Educational content; your prenatal care team's guidance always comes first.