Week 17
Your baby's bones are hardening
Your baby is now the size of a pomegranate, with tiny bones starting to harden and a heartbeat you might hear at your next appointment.
Baby's size this week
About the size of
a pear
- Length
- 5.12 in (13 cm)
- Weight
- 4.94 oz (140 g)
About the size of a pomegranate, with tiny bones starting to harden and a busy little heartbeat.
Sophie reads you this week
A short note, out loud·1:10
What to Expect This Week
Your baby is growing fast. This week, their tiny bones are starting to harden in a process called ossification. Their skeleton, which was once soft cartilage, is now turning into bone, giving them more structure and strength.
Their heartbeat is getting stronger. By now, their heart is pumping about 25 quarts of blood each day. If you have a Doppler at your next appointment, you might hear the rhythmic thump-thump of their tiny heart.
They’re practicing sucking and swallowing. Your baby is already honing their feeding skills, swallowing amniotic fluid and occasionally sucking their thumb. These reflexes will be essential once they’re born.
- Fat is forming. A thin layer of fat is starting to develop beneath their skin, helping regulate their temperature later on.
- Stretching out. Their legs are growing longer, and they’re starting to stretch and move more, even if you can’t feel it yet.
Things to Be Aware Of
Increased energy. Many people notice a boost in energy around this time. If you’re feeling more like yourself, take advantage of it! Just remember to pace yourself.
Skin changes. Pregnancy hormones can cause darkening of the skin, especially around the nipples, armpits, and inner thighs. You might also notice a dark line (called the linea nigra) running down your belly.
Leg cramps. Some people experience leg cramps at night, often due to changes in circulation or dehydration. Staying hydrated and stretching gently before bed might help.
What Might Happen This Week or Soon
Anatomy scan on the horizon. Many providers schedule the anatomy scan between weeks 18 and 22. This detailed ultrasound will check your baby’s growth, organ development, and placenta. It’s also a chance to find out the sex if you choose.
Feeling those first flutters. If you haven’t already, you might start to feel your baby move this week. These first movements often feel like gentle flutters or bubbles and can be easy to miss.
- Ask about the anatomy scan timing
- Stay hydrated to help with leg cramps
- Enjoy your energy boost, plan something fun!
Every flutter reminds me of the tiny miracle growing inside.
