18 Weeks Pregnant: What to Expect This Week
Eighteen weeks pregnant and your baby's ears are in their final position — and they're hearing everything. This is also the week the long-awaited anatomy scan is often scheduled.
Baby at Week 18: Size of a bell pepper
Baby's Development at 18 Weeks
The ears have reached their permanent position on the sides of the head, and hearing has developed dramatically. Baby can hear your heartbeat, the gurgles of your digestive system, and muffled versions of external sounds including your voice. Yawning, hiccupping (which you may be starting to feel as rhythmic twitches), and swallowing are regular occurrences. The myelin sheath — the protective coating around nerve fibres — is beginning to form, which will speed up nerve signals.
Your Body at 18 Weeks Pregnant
Between 18 and 22 weeks, most pregnant people feel the first undeniable movements. Once felt, they become increasingly regular and recognisable. Dizziness can be an issue as blood pressure tends to run lower in the second trimester; standing up slowly helps. Lower back pain is very common. Skin hyperpigmentation — darkening nipples, linea nigra, and sometimes melasma on the face — continues to develop.
Tips for Week 18
- Talk, read, and play music to your bump — your baby will recognise these sounds after birth.
- Book private early gender scans from week 16+ if you're curious and don't want to wait for the 20-week scan.
- Start building your birth plan — even a rough outline of your preferences gives you something to discuss with your provider.
- Consider starting aquanatal classes — swimming is one of the best exercises during pregnancy.
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Frequently Asked Questions
Can my baby hear me at 18 weeks?
Yes! From around 16–18 weeks, the baby's auditory system is developed enough to hear sounds. Your voice is particularly prominent — the sound travels through your body directly. Studies show newborns recognise and prefer their mother's voice above others, which is thought to be because of prenatal exposure.
What is the difference between the 12-week scan and the 20-week scan?
The 12-week scan primarily dates the pregnancy, confirms a heartbeat, and screens for chromosomal markers like nuchal translucency. The 20-week anatomy scan is a detailed structural survey of all the baby's organs and body parts. It's a much longer scan — typically 20–45 minutes — and checks for over 100 structural markers.
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