Pregnancy week 17: symptoms, baby size and tips
Pregnancy week 17 keeps you right in the second trimester, that stage when many women finally feel more energy and their bump is more and more present. Your baby is now about 13 centimetres, roughly the size of a pear, and this week they’re doing something really important: they start to store fat, practise breathing and their skeleton keeps getting stronger. Let me walk you through it, as always.
If you’re coming from pregnancy week 16, you’re on a great track. And to have the whole path at hand, check out our pregnancy week by week guide.
What is pregnancy week 17?
As always, pregnancy weeks are counted from the first day of your last period (LMP), not from conception. In week 17 you’re about 15 weeks from fertilisation, in your fourth month (weeks 14–17) and still in the second trimester, which runs from week 13 to week 28.
By now the placenta is fully established: it produces the hormones that keep your pregnancy going and feeds your baby through the umbilical cord, which is already thicker and stronger. Your uterus keeps rising up, so your bump is clearly visible and you usually have less pressure on your bladder than in the early months.
What can you see on a week 17 scan?
This still isn’t a routine scan week for everyone, but if you have one, it’s a lovely moment because your baby doesn’t stay still for a second:
- Their skeleton keeps hardening: the cartilage is turning into bone, especially in the limbs, and their back is getting stronger.
- They practise breathing: their diaphragm moves and makes breathing movements, although they’re not breathing real air yet (oxygen comes from the placenta and umbilical cord).
- They start to store fat: brown fat forms, which after birth will help them keep warm. Their skin is slowly becoming less see-through.
- They swallow amniotic fluid: they swallow it and their kidneys make urine, which goes back into the amniotic fluid. Meconium also starts to form in their gut.
- They hear you brilliantly: the tiny ear bones are becoming firmer and their hearing keeps sharpening. They pick up your voice, your heartbeat and the sounds of your digestion.
- They pull faces and suck their thumb: the mouth muscles let them suck their thumb, a reflex that gets them ready to breastfeed after birth.
If you haven’t taken a test yet, don’t worry: your hCG is still high and any test is very reliable. You can [take our free online p
