Day 172 of 280, second trimester
You are 24 weeks and 4 days
A natural temperature-control system in the uterus means your baby never gets cold.
108 days until your due date
The temperature inside the uterus is a third to half a degree higher than yours, and because your body temperature is so tightly controlled, your baby never gets cold and never needs to shiver. He has started laying down a special brown fat, especially around his neck, chest, and back, which after birth will be burned to produce energy and heat. In the uterus, though, he can't use it to warm himself.
Some heat is lost from your baby's skin into the amniotic fluid, through the uterus wall, and into your tissues, but temperature is mainly controlled by blood flow to the placenta. Its large surface area acts as a heat exchanger, keeping the blood leaving the baby in the umbilical arteries at the same temperature as the oxygen-rich blood returning in the umbilical vein.
After birth, babies lose heat quickly. They still can't shiver or maintain their temperature, so they cool down fast unless they're wrapped up warmly or held skin to skin soon after birth.
Good to know
Sensible snacking
As well as three meals a day, you may need snacks, which is fine as long as you choose the right foods rather than reaching for cookies and chips, whose empty calories won't do you any good.
With a little planning before you shop, healthy snacking is easy:
- Make dried fruit a mainstay, since it stores and travels well. Eat a wide variety, such as apricots, raisins, cranberries, cherries, and peaches, to get more nutrients.
- Lightly salted mixed nuts satisfy salt cravings healthily.
- Choose pretzels, oatcakes, or crackers instead of potato chips.
- Fresh fruit is convenient and nutritious, so carry a piece or two when you go out and keep fruit salad in the fridge. Keep frozen fruit handy to whip up a smoothie with vanilla yogurt.
- Frozen yogurt and low-fat ice cream make good snacks and desserts, and it's worth stocking up on low-fat yogurts.
Explainer
Snacks on the go
Always take a healthy snack with you when you leave the house.
Appointments and key dates around now
- Whooping cough vaccineUsually around 20 weeks, best before 32 weeks
Read the full 24 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.