Welcome to week 18 of your pregnancy! You’re nearly halfway there, and a lot is happening inside your body—even if you can’t see it all just yet. This stage of pregnancy is often when things start to feel real. Your belly’s showing, your baby’s moving, and your body is adapting in incredible ways.
So, what exactly is going on during week 18? Here’s everything you need to know, from baby development and common symptoms to helpful tips and what you can expect in the coming weeks.
How Big Is Your Baby at 18 Weeks?
At 18 weeks pregnant, your baby is about the size of a sweet potato—measuring roughly 5.5 to 6 inches long and weighing close to 6 to 7 ounces. That’s around 150 to 200 grams.
But it’s not just about size. This week, your baby is becoming even more human-like in appearance and function. Tiny details like fingerprints are forming, and those little ears are now in place and listening.
Baby Development at 18 Weeks
Your baby is going through a rapid growth phase right now. Here are some amazing developments happening during this week:
- Ears are fully developed and your baby can hear sounds from the outside world (and from inside, like your heartbeat and voice).
- Nervous system development is in full swing. Nerves are now covered with myelin, a protective coating that helps messages travel faster between brain and body.
- Bones are hardening, particularly the leg bones, which is why you may start feeling those little kicks and flutters soon.
- Lungs are forming air passages, though baby won’t breathe air until after birth.
- Genitals are visible if you’re planning a mid-pregnancy ultrasound around this time.
If you haven’t already scheduled your anatomy scan, it’s usually done between 18 and 22 weeks. This detailed ultrasound checks how your baby is developing and may reveal the gender if you want to know.
Your Body at 18 Weeks Pregnant
By now, you’re probably feeling more like yourself again—goodbye morning sickness, hello energy boost! But your body is still changing, and that comes with its own list of new sensations and symptoms.
Common Symptoms at 18 Weeks:
- Round ligament pain: This sharp or dull ache in your lower belly or groin area is due to your uterus stretching and your ligaments adjusting.
- Backaches: As your belly grows and posture shifts, your back may start to complain.
- Visible veins: Increased blood flow and volume can make veins appear more pronounced, especially on your chest and legs.
- Nasal congestion: Thanks to hormonal changes, you might feel a little stuffed up, even without a cold.
- Mild swelling: Your hands, feet, or face may begin to puff slightly—keep an eye out for sudden or severe swelling, and always let your doctor know.
Can You Feel Your Baby Move at 18 Weeks?
Possibly—especially if this isn’t your first pregnancy.
The first time you feel those tiny kicks is called quickening. For many first-time moms, it happens between 18 and 22 weeks. It might feel like flutters, bubbles, or gentle taps at first. If you haven’t felt anything yet, don’t worry—it’s coming.
What’s Happening With Your Uterus?
At this point, your uterus is roughly the size of a cantaloupe and sitting just below your belly button. You’re definitely starting to show, and maternity clothes are probably your new best friend.
Your growing uterus is pushing other organs out of the way, so digestive changes like heartburn or constipation may also show up. Drink plenty of water and eat fiber-rich foods to stay regular.
Tips for 18 Weeks Pregnant
Here are a few ways to take care of yourself this week:
- Start sleeping on your side: Left side is best for circulation, but don’t panic if you wake up on your back. A body pillow can help with positioning.
- Do gentle prenatal exercises: Walking, swimming, and prenatal yoga can relieve aches and improve mood.
- Moisturize your skin: As your belly stretches, keep it hydrated to help prevent itching or stretch marks.
- Hydrate, hydrate, hydrate: Your blood volume is increasing, and staying hydrated helps keep everything moving.
- Plan your mid-pregnancy ultrasound: This scan typically happens between weeks 18 and 22 and is one of the most detailed checks of baby’s anatomy.
What Should You Be Eating?
Your baby is growing fast, and nutrition matters. Focus on:
- Protein for cell growth (chicken, lentils, eggs)
- Calcium for bone development (dairy, leafy greens)
- Iron to prevent anemia (red meat, beans, fortified cereals)
- Folate to support your baby’s spine and brain (leafy greens, oranges, lentils)
Don’t forget your prenatal vitamins—they help fill in the nutritional gaps.
When to Call Your Doctor
Some symptoms are normal, but others deserve a phone call. Contact your healthcare provider if you experience:
- Severe cramping or abdominal pain
- Heavy bleeding
- Persistent dizziness or fainting
- Unusual discharge with odor
- Blurred vision or severe headaches
Your care team is there to support you. Never hesitate to reach out with concerns.
Looking Ahead: What’s Coming Next?
As you head toward week 20, you’re nearing the halfway mark! Expect to feel more movements, continue growing that beautiful belly, and possibly learn your baby’s gender if you choose to.
You may also notice a little more clumsiness or forgetfulness (“pregnancy brain” is real). It’s all part of the journey—and totally normal.
Final Thoughts on Being 18 Weeks Pregnant
This week marks an exciting phase in your pregnancy. You’re not in the early unknowns anymore, and the finish line is still far enough that there’s plenty of time to prepare. Your baby is developing quickly, your belly is growing, and every week brings something new.
Take time to connect with your baby, document your journey, and care for your own physical and emotional well-being. Whether this is your first child or your fourth, week 18 is a beautiful milestone on your road to motherhood.
