At 18 weeks pregnant, you’re well entrenched into your second trimester. Here’s what is happening with you and your baby.

Changes in Your Body

changes in your body

By now, your belly is growing quickly and you probably have an impressive baby bump. During your second trimester, you should plan to gain three to four pounds a month for healthy weight gain. If you started your pregnancy either underweight or overweight, these figures will change. Don’t be surprised if you gain a pound or so this week.

Weight Gain at Week 18
You should expect to have gained between 6 to 14 pounds total by the end of this week.

Your baby is becoming increasingly active and those gas bubbles or butterflies you feel in your tummy may be your baby’s first movements, which are also called quickening. It won’t be long before you feel his or her gentle kicks and stretches.

Your Baby

week 18 baby

Your baby is about 5 1/2 inches long this week and weighs around 7 ounces. This is a big week for your baby’s senses. The ears develop and pop out from the head. Your baby may begin hearing your voice. Your baby’s eyes now face forward and may detect light.

When Can A Fetus Hear?

Your baby’s nervous system is also rapidly developing. A substance called myelin, which sends messages from one nerve cell to another, now covers your baby’s nerves.

Many women undergo a second trimester ultrasound this week to see how things are progressing and to make sure baby’s organs are developing properly. If your baby cooperates during the ultrasound, you should be able to determine their gender.

Twin Development at Week 18

Fat stores are now accumulating beneath your babies’ skin. They each weigh around 7 ounces and measure 5 1/2 inches from crown to rump.

Pregnancy Symptoms

As long as your pregnancy is progressing without complications, your symptoms may be mild this week. You might experience increased energy, but also bouts of exhaustion. When you feel tired, taking a short power nap may be just the answer.

Carpal Tunnel Syndrome

carpal tunnel syndrome

Carpal tunnel syndrome is a common complaint among pregnant women. It is caused by a compressed nerve in the wrist and it results in tingling, numbness, and pain in the hand and arm. Sixty-two percent of pregnant women have reported symptoms.

If you work at a computer, adjust your workstation for ergonomics. You should also avoid prolonged exposure to vibrations, such as power tools or lawn mowers. A wrist splint may also help relieve the painful symptoms.

The good news is that, in most pregnant women, carpal tunnel syndrome resolves itself after giving birth. If you suspect that you may have carpal tunnel syndrome, speak with your doctor.

Body Aches

hot water bottle

Body aches, such as back, groin, or thigh pain, may begin plaguing you in your second trimester. Your body is rapidly changing. As your uterus expands, pushing your stomach out, your center of balance will change. This can contribute to body aches. The increased weight of your baby can also put extra pressure on your pelvic bones.

Hot or cold compresses or massage may help. Make sure you look for a masseuse who specializes in prenatal massages and let the masseuse know how far along you are when you book your appointment.

Nighttime leg cramps are also common. Stay hydrated and stretch your legs before bed. This may help prevent cramps. Exercise during the day may also help.

Skin Changes and Itching

skin cream

An itchy abdomen is common during pregnancy. You may also have itchy hands or feet. Avoid hot showers and itchy or tight fabric. A gentle moisturizing cream may also help.

In addition to itchiness, you may also begin to develop a linea nigra, or a dark line down your abdomen. This is a benign condition, and usually resolves after birth.

Linea Nigra: Should I Be Worried?

Stretch marks are perhaps the most well-known and common skin change during pregnancy, affecting up to 90 percent of women. They usually begin appearing during your second trimester. Unfortunately, there is little you can do to prevent them.

A recent review of topical prevention methods found that cocoa butter and olive oil, commonly used topical treatments, are not effective for preventing or reducing the appearance of stretch marks. Most stretch marks begin to slowly fade over time after pregnancy.

Additional Symptoms

Symptoms you’ve experienced throughout your pregnancy such as heartburn, gas, bloating, and frequent urination may continue this week. You may also experience nasal and gum problems, including congestion, gum swelling, or dizziness.

Things to Do This Week for a Healthy Pregnancy


If it's been a while since you’ve seen a dentist, schedule a visit. Pregnancy hormones may cause irritated, bleeding gums. Pregnancy increases the risk of periodontal disease, which has been linked to preterm labor. It’s safe to have routine dental care during your second trimester, but dental X-rays should be avoided.

If you haven’t already, you may want to start researching pediatricians. Choosing a pediatrician for your baby is an important decision, so it’s a good idea to begin the search early. Asking friends for referrals, or calling the local hospital and asking for the physician referral department is a great starting point.

Now is also a good time to begin planning for your baby’s birth. If you want to take childbirth classes, contact your healthcare provider or the hospital where you plan to deliver to see what is available. Childbirth classes help you prepare for labor and delivery, and educate you about pain relief and what steps will occur in an emergency.

To keep your weight gain at a healthy level, continue to eat a nutritious diet. This should include calcium and iron-rich foods, and foods high in folic acid, such as leafy greens and citrus fruits. If you crave sweets, eat fresh fruit instead of cakes or processed sweets. Avoid high-calorie and fried foods. Overweight women with a BMI of 30 or above run a higher risk of developing gestational diabetes.

When to Call the Doctor


You should call your doctor if any of the following symptoms occur in your second trimester:

  • vaginal bleeding
  • increased vaginal discharge or discharge with odor
  • fever
  • chills
  • pain with urination
  • moderate to severe pelvic cramping or lower abdominal pain

If you experience swelling of your ankles, face, or hands, or if you swell or gain a lot of weight quickly, you should also call your doctor. This could be an early sign of preeclampsia, which is a serious pregnancy complication that requires prompt medical attention.

You should also contact your doctor before taking any new medications or herbal remedies.

You’re Almost Halfway There!

At 18 weeks, you’re almost halfway through your pregnancy. In the upcoming weeks, your belly will continue to grow, as will the bond you and your baby share.