Day 219 of 280, third trimester
You are 31 weeks and 2 days
Your baby is now the length she'll be at birth, but she's still very thin and needs to gain fat and muscle.
61 days until your due date
Your baby's muscle and fat keep increasing. Her skin is thicker and less see-through, looking pink rather than red as the blood vessels beneath are covered by more flesh. Her pituitary gland is making growth hormone, but before birth it doesn't affect her growth; insulin and insulin-like growth factors are key instead. Her skeleton is close to its final size, so her length is set, but she's still very skinny.
A sonographer can estimate your baby's weight well from a scan, but her birth weight will depend a lot on when she's born. She'll keep growing throughout pregnancy, although in the last few weeks the growth is mainly fat rather than muscle.
If you're trying to guess her birth weight, the latest research suggests it depends a lot on "imprinted" genes: genes marked as coming from the father promote growth, while those from the mother limit it to preserve her resources.
Focus on
Twins: Dressing your babies
Twins look adorable in matching outfits, and you'll probably buy, and be given, lots of them. But identical twins are much easier to tell apart when dressed differently, and it helps everyone see them as individuals, which is good for their development.
Be practical, too: will you change both every time one gets dirty? If only two clean onesies are left, that's what they'll wear, matching or not. Newborns don't care, but twins always dressed alike may become conscious of it as toddlers and get upset if they're dressed differently.
It's your choice, but you could:
- Dress them in matching outfits in different colors, or the same colors in different styles.
- Dress them identically only on certain occasions, such as family photos or special events.
- Give one batch of identical outfits to one twin and the next batch to the other.
Appointments and key dates around now
- Whooping cough vaccineUsually around 20 weeks, best before 32 weeks
- RSV vaccineFrom 28 weeks
Read the full 31 weeks pregnant guide
This is general information based on NHS guidance, not medical advice, and every pregnancy is different. Talk to your midwife or GP about anything that worries you. If your baby's movements slow down or change, or you have bleeding, severe pain or leaking fluid, call your maternity unit straight away. In an emergency, call 999.