2nd trimester · Week 27
27 weeks pregnant
REM sleep and practice breathing
Brain-wave patterns include REM-like sleep. Rhythmic breathing movements continue. Many clinics treat the next week as the official start of the third trimester.
How big is your baby at 27 weeks?
- Length
- 36.6 cm
- Weight
- 875 g
- Size
- Corn
On average about 36.6 cm long and 875 g. Size comparison: Corn.
These are averages; every baby grows at their own pace.
How is your baby developing at 27 weeks?
The fetus may have hiccups you feel as regular taps. Fat is increasing. Average length is about 36–37 cm; weight often near 875 g. Eyes can open and close.
What changes in your body at 27 weeks?
Sciatica-like shooting pain, restless legs, and heartburn can intensify. The fundus is high. Stretching the abdomen can itch.
Tips for this week
A pregnancy pillow and shorter walks may ease pelvic nerve pain; numbness that worsens or comes with weakness needs review. Tdap vaccination is often recommended in the third trimester (timing varies by country, commonly 27–36 weeks) to pass pertussis antibodies.
