Noticing a rumbling in your tummy?

It could be pregnancy hunger pangs — or it could be the very first signs of fetal movement, which can happen at around week 18 of pregnancy.

Your Baby at Week 18

At a Glance

Tiny fingerprints
Tiny fingerprints
Your one-of-a-kind baby is truly one of a kind now, with unique fingerprints on those little fingertips and toes.
Nerve protection
Nerve protection
Myelin, a protective insulation, is starting to form around baby-to-be's nerves. This covering continues to grow until your baby's first birthday.
Girl and boy parts defined
Girl and boy parts defined
Having a girl? The fallopian tubes and uterus are now in proper position. A boy? Genitals may be visible on your next ultrasound.

18 weeks pregnant is how many months?

If you're 18 weeks pregnant, you're in month 5 of your pregnancy. Only 4 months left to go! Still have questions? Here's some more information on how weeks, months and trimesters are broken down in pregnancy.

How big is my baby at 18 weeks?

At 5½ inches long from crown to rump and 5 to 6½ ounces in weight — about the size of that boneless chicken breast you're making for dinner — your baby may be large enough now or anytime in the next few weeks for you to feel twisting, rolling, kicking and punching in the womb.

Baby is yawning

Now for the skill of the week: The art of the yawn has been mastered by your baby, along with hiccupping, which you may feel soon, too!

In fact, you might catch a glimpse of that adorable yawn and all those other fetal movements at your ultrasound this month.

Baby's nervous system is maturing quickly

Something you won't see on the ultrasound — but you'll learn is in working order — is your baby's nervous system, which is maturing rapidly when you're 18 weeks pregnant.

A network of nerves, now covered with a substance called myelin that helps speed messages from nerve cell to nerve cell, are forming more complex connections.

And those in the brain are further developing into the ones that serve the senses of touch, taste, smell, sight and hearing.

Speaking of hearing, your baby's is growing more acute and baby can finally fully hear you this week, making your little one more conscious of sounds that come from inside your body. Meaning you could both be listening to each other hiccup!

Your Body at Week 18

18 weeks pregnant woman

Quick growth

Is it a girl? A boy? How about a sizeable fruit or vegetable? At 18 weeks, your baby is about the length of a cucumber and your uterus is around the size of a sweet potato — see how you're working your way through the produce department? It can be felt about 1½ inches below your belly button — so have a feel.

Your 18 weeks pregnant belly

When you’re 18 weeks pregnant, you'll likely look noticeably pregnant, since your baby and uterus are growing rapidly. But remember that every woman is different as is each pregnancy, so even this far along, some still have small bumps while others have popped a lot.

All baby bumps at 18 weeks pregnant are fine and normal and may vary based on how much weight you and baby are gaining, your height and build, and whether this is your first pregnancy or not.

Just don’t size up your 18 weeks pregnant belly next to those of pregnant friends at the same stage, or worry that you’re measuring too big or too small. If you’re really concerned, you can always talk to your practitioner, but rest assured that if you and your baby are tracking normally at your prenatal appointments, everything is likely just fine.

Your back aches

Something else you may be feeling right now: back pain. Your growing uterus shifts your center of gravity — which means your lower back is pulled forward while your abdomen is thrust out — good for tipping off the person who got the last seat on the bus that you're pregnant, bad for your back muscles.

Couple that with the changes that the pregnancy hormone relaxin is instituting — namely relaxing all your ligaments, including those that attach your pelvic bones to your spine, and loosening joints — and that leaves you with backaches and pains, not to mention a shifting posture.

Reduce pain by using a foot rest to elevate your feet slightly when sitting. When standing, place one foot on a low stool when possible to take some pressure off your lower back. A long, warm bath can also do wonders. And if your back pain just won't quit, be sure to talk to your practitioner.

Reducing heartburn

Forget the burrito with extra jalapeños — sometimes even a bite of toast will set your gut on fire these days. That's the problem with heartburn— an all-too-common symptom that can persist throughout your pregnancy. An ounce of prevention may be worth a pound of Tums — although you might want to keep those handy, too, since they'll banish the burn while boosting your calcium intake.

For starters, eat slowly and chew thoroughly. Try not to eat lunch on the run or gobble your dinner standing up, and eat smaller meals and snacks rather than five-alarm gut bombs.

After you finish eating, sit upright for a few hours, or as long as you can last without collapsing into bed, and sleep with your head elevated, which also helps with the snoring. And do skip anything on the menu with a picture of a flame next to it!

Pregnancy Symptoms Week 18

Fetal movement
Fetal movement
Bloating and gas
Bloating and gas
Leg cramps
Leg cramps
Bleeding gums
Bleeding gums
Edema (swelling in feet and ankles)
Edema (swelling in feet and ankles)
Stretch marks
Stretch marks

Tips for You This Week

Don’t make any sudden moves

During pregnancy, progesterone increases the flow of blood to your baby, resulting in lower blood pressure and reduced blood flow to your brain — giving you that faint feeling all over.

To help stave off dizziness, always stand up from a sitting or lying position slowly.

Interview pediatricians

Now’s a great time in your pregnancy to interview potential pediatricians. After all, there’s a good chance that the doctor will first see your baby within 24 hours of your little one’s birth.

So ask a lot of questions before you make your selection and broach topics like appointment availability, hospital affiliations, vaccines and circumcision.

Time for relaxin?

Unfortunately, we don't mean "relaxing." During the second trimester, your body releases relaxin, a hormone that (as the name implies) loosens the ligaments that hold your bones together. The result: an achy pelvis and hips — and maybe even bigger feet!

You may be cursing this pregnancy hormone now, but when you're trying to push out your baby's big head, you’ll be thanking relaxin for doing its job.

Pump iron

Even red-meat eaters can have a hard time getting enough iron from their diets. If you're someone who sticks to plant-based foods, you'll have to double your efforts to pump up the iron — vegan and vegetarian moms-to-be have a higher risk for iron-deficiency anemia.

Foods like beans, soy products, oat bran, barley, pumpkin seeds, dried fruits, spinach, seaweed, Jerusalem artichokes and blackstrap molasses all have some iron in them, but you may also need to take an iron supplement to make sure you're meeting your daily quota. Ask your practitioner whether that’s the case.

Be wary of supplements

Herbal supplements do make the most tempting of promises — especially when pregnancy leaves you with few self-medicating options. Would it really hurt to pop a couple of ginkgo biloba capsules to give your brain cells a fighting chance of remembering to pay this month's electric bill? After all, the bottles say "all natural"…and you did buy them at the health food store.

Actually, it could hurt — particularly now that you're sharing those pills with a little someone else. Herbs and herbal remedies are not tested or approved by the Food and Drug Administration (FDA) prior to going on the market and are not required to undergo clinical trials, so their safety, or lack thereof, is unknown.

Even supplements that you've heard could be helpful could actually be harmful at different points during your pregnancy — by causing premature labor if taken too early, for instance.

And a number of herbs — such as basil oil, black or blue cohosh, clove oil, sassafras, wild yam and many others — can be downright dangerous if taken anytime during pregnancy. Be safe and check with your practitioner before you pop any pill.

Avoid some workout moves

Certain exercises may work great for the non-pregnant set, but now that you’re expecting, don't even think about trying them.

Just say no to upside-down "bicycles," shoulder stands, or flat-on-your-back positions after the fourth month.

Also off-limits: deep-knee bends, back bends, jumping and bouncing.

Get ready for tiny kicks

You'll probably notice baby's first little kicks anytime between weeks 18 and 22 — and sometimes as late as weeks 23 or 24 for first-time pregnancies.

Those tiny feet can be felt in many different ways: as the merest flutter, the most insistent slug or gas bubbles that aren't gas at all.

As for when and how you'll feel your baby move? Several factors come into play: a mom's size (the slimmer you are, the more likely you'll feel movements earlier); your muscle tone (the laxer the uterine muscles, the easier it is to feel those kicks — which is why second-timers generally feel them sooner); and the baby's position (it’s trickier to notice movement when your baby kicks facing in).

An incorrect due date can also throw off the recognition of those monumental first kicks. Don't worry: There's no mistaking the real thing once your baby gets the technique down — and gets big enough to pack a serious punch.

From the What to Expect editorial team and Heidi Murkoff, author of What to Expect When You're Expecting. What to Expect follows strict reporting guidelines and uses only credible sources, such as peer-reviewed studies, academic research institutions and highly respected health organizations. Learn how we keep our content accurate and up-to-date by reading our medical review and editorial policy.

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