§first trimester · week 13 of 40
you're 13 weeks pregnant.
last revised · baby is about 7.4 cm (2.9") · 23 g (0.81 oz)
about the size of a peach.
Welcome to the second trimester. Your baby has unique fingerprints and can already make tiny facial expressions.
this week's highlights
- Fingerprints form
- Second trimester begins
- Facial expressions practice
- Intestines move from cord to belly
how your baby looks
Proportions are evening out — the head is now about a third of the body length. Skin is still translucent so blood vessels show through.
body in focus
- head
- Tiny facial muscles can smile, frown, and squint.
- body
- Intestines, which had been growing into the umbilical cord, move into the belly.
- hands
- Each fingertip has a unique fingerprint pattern.
- feet
- Footprints are unique too.
what's happening in your body
Energy returns for many people. You may start to show a small bump. Increased blood flow can give skin a glowing look (the 'pregnancy glow' is real).
gentle tips
- Buy a few maternity essentials — leggings, a stretchy bra.
- Talk to your provider about an anatomy scan in weeks 18–22.
- Start sleeping on your left side to maximize blood flow.
- Keep hydrating — your blood volume is up 30–40%.
- Use unscented lotion on a growing belly to reduce itchiness.
what to expect next
Movement may be felt for the first time between weeks 16–22, called quickening. Each person feels it on a slightly different timeline.