You’re getting close to the halfway point! By now, you may be enrolled in childbirth classes or prenatal yoga, and this week begins the window for your anatomy scan! That’s both a fun and exciting milestone and a significant one, medically and developmentally.

At 18 weeks pregnant, your baby and your body continue to grow. It’s likely that your pre-pregnancy clothes no longer fit, and this might even include your shoes!

Your Baby’s Development At 18 Weeks

Your baby is not between 8 and 9 inches long and may weigh as much as half a pound! (That’s about like picking up two sticks of butter.)

Your baby is practicing some great skills for outside the womb, including hearing, swallowing, and sucking. He’s also yawning and hiccuping! When you see him on an ultrasound, you may witness him rolling over, doing little flips, punching, kicking, and even sucking his thumb!

Baby now has unique fingerprints, and the gallbladder and digestive system are developing and preparing for birth!

Quick Overview: Baby's Development At 18 Weeks Pregnant:

• Baby is 8 to 9 inches long and may weigh up to half a pound (about two sticks of butter).
• Practicing key skills like hearing, swallowing, and sucking.
• Yawning and hiccuping are now part of the baby’s movements.
• Active on ultrasound—may be seen rolling, flipping, punching, kicking, and sucking thumb.
• Unique fingerprints have formed.
• Gallbladder and digestive system are developing and preparing for birth.

Mother’s Symptoms At 18 Weeks

Breast Changes

By now, most women will notice changes in their breasts. They may be heavier and grow as much as a few cup sizes. Your band size may also increase.

At the same time, you may notice other changes, like visible blueish veins under the skin and larger nipples and areolae. Some women will leak colostrum throughout from now until birth, although others will not see a drop until the third trimester, and some won’t even have colostrum until the baby is born.

If your nipples crack or bleed, speak to your doctor. They can prescribe medication that will treat this and also prevent infection.

Digestive Symptoms

You may continue to have heartburn and indigestion throughout the rest of your pregnancy. Basic OTC treatments like Tums and Rolaids are generally considered safe, but you should avoid anything with aspirin, magnesium trisilicate, or sodium bicarbonate. It’s always okay to check with your doctor if you’re unsure about a specific medication!

Cravings also may be amping up as you move through the second trimester. Focus on getting your body the nutrients it needs, but indulging within reason is okay. Talk to your doctor if cravings seem overwhelming or if you crave non-food ‘snacks’ like dirt, clay, or paper. They may recommend a supplement that will safely meet the need your body is communicating.

Nasal/Sinus Symptoms

Some women will have pregnancy rhinitis, a weeks-long stuffy nose for no apparent reason. Some will even have nosebleeds. Saline nasal sprays are typically considered safe but don’t take oral decongestants without talking to your doctor. They can reduce blood flow to your baby and cause maternal hypertension, US Pharmacist warns. Your doctor may prescribe a minimal dose if the benefits outweigh the risks. (They may also dry out your sinuses and increase the risk of nosebleeds.)

If a nosebleed is severe or doesn’t stop, seek medical care.

Pain & Cramping

Pregnancy can come with a wide variety of discomforts, but pain should be taken seriously. However, some types of pain are normal, within limits.

Round ligament pain can feel like an intense cramp or stabbing sensation in your abdomen. It may even extend into your groin. It can be a scary feeling, but the stretching of round ligaments causes it as they work to support your growing uterus. It’s usually okay to take OTC pain meds, but you may find that simply changing positions or taking a warm bath relieves this. However, pain that doesn’t go away calls for a check-in with your doctor!

Your legs may cramp or have symptoms of restless leg syndrome (RLS), in which you feel the desperate urge to move your legs as soon as you get settled and relaxed. Some moms find that adding bananas to their diet helps, thanks to the additional potassium. If the symptoms are severe, your doctor may be able to offer a prescription, but most typical RLS meds are off the table during pregnancy.

Do mention RLS symptoms to your doctor even if they’re not too severe, because there’s some evidence linking them to longer labors and even c-sections, so your doctor may want you to try an iron supplement or other treatment.

Feeling Hot, Tired, & Dizzy

Pregnancy brings extra pressure on your organs, extra blood volume, and extra work for your lungs.

Because of all this, don’t be surprised if you get overheated easier than usual, especially as your baby grows! You also might find that exertion wears you out more quickly or even leaves you short of breath and needing a break. Some women may also find that they get dizzy or lightheaded.

All of this is worth mentioning to your doctor at your next appointment, but if symptoms are severe or ongoing, faint, pass out, or have chest pains, call your doctor immediately.

Losing Sleep

Your family and friends keep saying, “You’d better get some sleep now because when the baby comes, you won’t get any!” and you just want to scream because you already can’t get any decent rest!

It’s not just the RLS symptoms and the heartburn that makes you feel like your gut is doing backflips every time you lie down — though those can be disturbing enough. As many as 80% of pregnancies also present with general insomnia. Even after you’ve managed to calm your legs and settle yourself at a recline to minimize the discomfort from heartburn and indigestion, you can’t get to sleep!

This can be due to hormonal changes, anxiety, the pressure your heavier uterus places on your back and on other organs, and your increased heart rate, among other causes.

Unfortunately, it’s not just an annoyance but can result in pregnancy complications, including increasing the risk of preeclampsia (which we’ll talk about more below). Even short of this, it results in you being more tired during the day, more at risk if you have to drive, and more stressed, which is also risky for both you and the baby.

The Cleveland Clinic advises patients to try lifestyle changes first: make sure they’re getting enough calcium and magnesium; practice good sleep hygiene (including turning off screens before bedtime and keeping their bedroom at a comfortable temperature); and use relaxation techniques, among other measures.

If you’ve tried these methods and lack of sleep is disturbing your daytime life, it’s time to talk to your doctor. They may prescribe medications if the benefits outweigh the risks.

Skin & Hair

One of pregnancy’s more pleasant side effects is fuller, healthier hair and the pregnant ‘glow.’ After spending the first-trimester battling acne and oily skin, many women find that their skin does take on a healthy glow at this point.

There are other possible skin changes, though, including the appearance of dark patches called chloasma. These are most common on the face, and may affect as many as 75% of pregnant people. They usually fade on their own after some time. Still, a review in Clinical, Cosmetic, & Investigational Dermatology in 2024 concluded that up to 30% of cases do not fade after delivery, with some lasting even a decade after.

Sunscreen during the first trimester may decrease the risk, and though treatments are available, they’re not recommended during pregnancy.

Pre-Eclampsia Symptoms

Pre-eclampsia is a serious complication in pregnancy, and it requires ongoing monitoring until delivery. It can even need an early delivery for both mom and baby’s safety.

Many of the warning signs of preeclampsia are typical pregnancy symptoms that may be more intense or present a bit differently. For example, some swelling can be expected, but facial swelling or uneven swelling (one leg swelling more than the other) might be a sign of preeclampsia.

You’ll also expect to gain weight by this point in pregnancy, but sudden significant weight gain may be a cause for concern.

Headaches can be shared in pregnancy, but severe headaches or headaches that don’t go away may be a warning of pre-eclampsia.

Shortness of breath, dizziness, and fatigue can all be normal, but if severe or ongoing, they may be symptoms of pre-eclampsia. The same can be said for nausea and vomiting (although any nausea and vomiting continuing at this point should be reported to your doctor).

Vision changes also may be a symptom of pre-eclampsia and always warrant medical care.

18 Week Pregnancy Symptoms Quick Recap:

• Increase in breast size, visible veins, larger nipples and areolae, leaking colostrum, cracked or bleeding nipples.
• Heartburn, indigestion, increased cravings, unusual cravings (e.g., dirt, clay, paper).
• Stuffy nose (pregnancy rhinitis), nosebleeds.
• Round ligament pain, leg cramps, Restless Leg Syndrome (RLS).
• Overheating, shortness of breath, dizziness, fainting, chest pain.
• Insomnia, difficulty finding a comfortable sleeping position, frequent waking.
• Fuller, thicker hair, pregnancy “glow,” dark patches on the skin (chloasma).
• Swelling (especially in the face or uneven swelling in limbs), sudden significant weight gain.
• Severe or persistent headaches, nausea, vomiting, vision changes.

When To Contact Your Doctor

Pre-eclampsia

If you’re seeing signs of preeclampsia, as described above, contact your doctor immediately. Preeclampsia is serious and one of the signs of a high-risk pregnancy. If you’re unsure whether symptoms are severe enough to warrant a check, it’s okay to call and ask for clarification!

Dehydration

Dehydration is common in pregnancy (and may contribute to many other symptoms, including headaches and constipation) but can also cause serious complications. If you go for extended periods of time unable to pass urine, or see other signs of dehydration, contact your doctor.

Bleeding & Discharge

While spotting can be expected in early pregnancy, any bleeding in the second trimester should be reported to your doctor. (Some may be normal after internal exams, as this may irritate your sensitive cervix.)

A milky whitish discharge is also normal, but if you notice a change in color (green or gray), a foul smell, or if it’s accompanied by itching or swelling, call your doctor. Vaginal infections and UTIs are both common in pregnancy, but must be treated because they can cause pregnancy complications.

If you notice any leakage that seems like it might be amniotic fluid, contact your doctor immediately.

Unrelenting Pain & Cramping

Some pain during pregnancy, including headaches, backaches, crampy pain, or round ligament pain, is normal, but it’s still okay to let your doctor know during routine appointments. However, anything that is ongoing or doesn’t ease with position changes, rest, hydration, and/or OTC meds should be reported to your doctor.

What Should Mom Be Doing At 18 Weeks?

Try to sleep on your side, but don’t panic if you wake up on your back. Side sleep, especially on your left side, can increase blood flow to the fetus and may keep your body more comfortable. A pregnancy pillow may help, or you can just use extra pillows to help support your body in a comfortable position.

Despite common sayings about “eating for two,” you’ll only need about 340 extra calories per day at this point, not double your usual amount. Focus on getting the necessary vitamins and nutrients, rather than eating ‘extra.’

Keep active as long as it’s safe for you and your baby. You can check with your doctor if you’re unsure how much activity is secure. Still, continuing most normal activities is okay in most healthy pregnancies — although some more strenuous activities like weight-lifting or downhill skiing might be off the table.

If you are planning a maternity photoshoot, a baby shower, or other events and haven’t yet scheduled them, it’s time! Some venues stay scheduled months in advance! This is also true of birth classes, so sign up early!

Keep your body comfortable. Wear clothing that fits loosely and is not constricting. It may be time to buy new shoes, as you may find that your feet have grown a size! Make sure to pick shoes that are supportive and comfortable, whether new or old, to reduce back and leg pain. A belly band may also help with back pain.

Use a gentle lotion (cocoa butter works well and may be cheaper than lotions specifically marketed for stretch marks) on your belly to ease stretch marks. This isn’t purely aesthetic—stretch marks can also itch or be generally uncomfortable, and a lotion or moisturizer may help.

Quick Recap Of What Mom Should Be Doing At 18 Weeks Pregnant:

• Try to sleep on your side, especially the left, to improve blood flow and comfort.
• You only need about 340 extra calories daily, not double your usual intake.
• Stay active as long as it’s safe; check with your doctor if unsure.
• Plan maternity events early, including photoshoots, baby showers, and birth classes.
• Wear loose, comfortable clothing; your feet may grow, so supportive shoes are essential.
• A belly band may help with back pain.
• Use a gentle lotion (like cocoa butter) to ease stretch marks and discomfort.

What To Look Forward To

Your anatomy scan — a mid-pregnancy ultrasound that is sometimes called an anomaly scan — maybe this week or in the near future. It’s usually scheduled between 18 and 22 weeks. While it’s medically essential, it’s also exciting! This may be the best view you’ll get of your baby before birth (unless you need additional ultrasounds later or choose to seek out novelty ones for images), and you may even find out your baby’s sex!

You’ll also soon feel your baby moving! This is a great milestone that helps reassure you that your baby is growing and healthy and can also make you feel more connected to your little one.