18 Weeks Pregnant: What to Expect, Baby Development & Anatomy Scan Preparation
18 weeks pregnant: what to know right now
Baby: Size of a sweet potato (~5.6 inches, ~6.7 oz) · Fingerprints forming, yawning, hiccupping, responding to sound · Body: Possible first movements (quickening), round ligament pain, visible bump · Key appointment: Anatomy scan (20-week scan) scheduled for weeks 18–22 — the most detailed scan of pregnancy
Here's everything happening with your baby and your body this week.
The anatomy scan (typically at 18–22 weeks) checks all major organs and structures. Write your questions down beforehand.
🌱 Baby's development this week
- Ears now in final position — baby can hear clearly
- Baby yawning and stretching regularly
- Unique fingerprints now complete
- Myelin sheath forming around nerve fibers
By 18 weeks, babies can hear sounds from outside the womb — initially as muffled vibrations. By 24 weeks, hearing is sophisticated enough to recognize their mother
🤰 Your symptoms this week
💛 Changes in your body
- Kicks becoming stronger and more regular
- Possible leg cramps at night from blood flow changes
- Dizziness if lying on back — avoid supine position
- Some women notice nasal congestion worsening
Many women report
Preparing for the Anatomy Scan at 18–22 Weeks
The anatomy scan (also called the 20-week scan, fetal anomaly scan, or TIFFA scan) is the most comprehensive ultrasound examination of pregnancy. Scheduled between weeks 18–22, it checks every major organ and structure in detail.
What the scan looks for:
- Brain, spine, and skull development
- Heart structure (4 chambers, correct connections)
- Kidneys, stomach, abdominal wall
- Lips and face (checking for cleft lip)
- Arms, legs, hands, and feet
- Placenta position (checking for placenta previa)
- Amniotic fluid volume
What the scan does not definitively detect: It checks for most major structural anomalies but does not screen for Down's syndrome (that's the 12-week combined test), nor does it detect all abnormalities. A normal anatomy scan is very reassuring, but not a guarantee.
Gender: If you want to find out, tell the sonographer at the start — they may not offer otherwise. In some countries/systems, gender is not disclosed at this scan. Ask your provider in advance.
Practical preparation: A full but not overfull bladder makes the scan clearer. Eat beforehand — the scan can take 30–60 minutes. Bring your partner or support person if you want them present.
🥗 Nutrition focus
- Iron needs are highest in second and third trimester — 27mg/day minimum
- Eat a rainbow: different colored vegetables provide different antioxidants for fetal protection
- Limit caffeine to 200mg/day maximum — one coffee or two teas
Anatomy scan at 18–22 weeks: the most comprehensive view of baby
✅ This week's checklist
Frequently Asked Questions: 18 Weeks Pregnant
How big is baby at 18 weeks?+
At 18 weeks, your baby is approximately 5.6 inches (14.2 cm) long and weighs about 6.7 oz (190 g) — roughly the size of a sweet potato. The baby can hear muffled sounds from outside the uterus, including your voice.
What are common symptoms at 18 weeks pregnant?+
Common symptoms at 18 weeks: visible bump, possible first movements (quickening — often felt as bubbles or flutters), round ligament pain, backache, nasal congestion, increased appetite, and if you have an anterior placenta, you may not feel movement until 20–24 weeks.
When is the anatomy scan done?+
The anatomy scan (20-week scan) is typically scheduled between weeks 18–22. At 18 weeks you may have already been booked in, or your appointment is coming up. It's the most detailed scan of pregnancy and checks all major fetal structures.
Can you find out the gender at 18 weeks?+
Yes — gender is usually visible on ultrasound from week 16 onward, and clearly identifiable at the anatomy scan (18–22 weeks). Whether the sonographer will tell you depends on local policy and whether you ask. Tell the sonographer at the start of the appointment if you want to know.
What is quickening at 18 weeks?+
Quickening is the first noticeable fetal movement — often described as bubbles, flutters, or gentle taps. Most first-time mothers feel it between weeks 16–22; women in subsequent pregnancies recognise it earlier. An anterior placenta (at the front) can delay when you first feel movement.
Track your pregnancy week by week
Interactive guide · 40 weeks · Fruit size visualizations · Personalized tips
Explore Week 18 in the Interactive Guide →