Trimester 2
18 Weeks Pregnant
At week 18, your baby is focusing on growth and refining their movements. They are starting to hear the sounds of your heartbeat and voice, and their tiny muscles are getting stronger as they practice kicking and rolling in the womb.
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Your baby is the size of a Bell pepper
14 cm
Length
190 g
Weight
Week 1Week 13 - End of Trimester 1Week 27Week 42
Baby's Development This Week
At week 18, your baby is focusing on growth and refining their movements. They are starting to hear the sounds of your heartbeat and voice, and their tiny muscles are getting stronger as they practice kicking and rolling in the womb.
- If female, the uterus and fallopian tubes are formed.
- If male, genitals may be visible on ultrasound.
- Myelin (nerve coating) begins forming.
- The fetus can yawn and hiccup.
- Ears are in their final position and hearing is developing.
- About 14.2cm — the size of a bell pepper.
Your Symptoms at Week 18
Week 18 is part of the 'honeymoon phase' of pregnancy. You likely have more energy now and your bump is starting to show. You might notice changes in your hair and skin, and you're probably starting to feel the wonderful sensation of your baby moving.
Quickening (first fetal movements)
Note when you first feel movement — tell your provider! (mild)
Note when you first feel movement — tell your provider! (mild)
Lower back pain
Prenatal yoga, proper posture, and supportive shoes help. (moderate)
Prenatal yoga, proper posture, and supportive shoes help. (moderate)
Swollen feet or ankles
Elevate your feet; avoid standing for long periods. (mild)
Elevate your feet; avoid standing for long periods. (mild)
Trouble sleeping
Sleep on your left side with pillows between your knees. (moderate)
Sleep on your left side with pillows between your knees. (moderate)
When to Call Your Doctor
- Sudden swelling of face or hands (preeclampsia warning)
- Severe headache with visual changes
- Fluid leaking from vagina
- Regular contractions
Week 18 Checklist
- ✓Anatomy scan coming up — prepare questions for your provider (recommended)
- ✓Begin a kick-count awareness (formal counts start at 28 weeks) (optional)
- ✓Research infant car seats (needed before birth) (recommended)
- ✓Adjust sleeping position to left side (recommended)
Frequently Asked Questions
Continue Your Pregnancy Journey — Week 18
← →
Week 17 of Pregnancy
Review what happened last week with your baby's development
← →
Week 19 of Pregnancy
What's coming next week — new developments and symptoms to expect
Guide
Second Trimester Overview
Everything happening during your second trimester — symptoms, tests, and milestones
Symptom
Heartburn & Indigestion
Safe remedies and foods to avoid during pregnancy
Symptom
Back Pain in Pregnancy
Exercises, positions, and when back pain is serious
Tool
Kick Counter
Start counting fetal movements — kicks should begin around week 18
Related
Anatomy Scan Ultrasound
The detailed 20-week scan that checks all major organ systems
Nutrition
Second Trimester Nutrition
Iron, calcium, and the best foods for your growing baby
Medical Disclaimer: This content is for informational purposes only and is not a substitute for professional medical advice. Always consult your healthcare provider for personalized guidance about your pregnancy.