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

Changes in your body

By now, your belly is growing quickly. During your second trimester, you should plan to gain 3 to 4 pounds a month for healthy weight gain. If you started your pregnancy underweight or overweight, this amount will change. Don’t be surprised if you gain a pound or so this week.

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

Your 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. Their ears develop and pop out from their head. Your baby may begin hearing your voice. Your baby’s eyes now face forward and may detect light.

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

Many women undergo a second trimester ultrasound this week to see how things are progressing and to make sure their baby’s organs are developing properly. You may also be able to find out your baby’s sex during the ultrasound.

Twin development at week 18

Each baby now weighs around 7 ounces and measure 5 1/2 inches from crown to rump. Fat stores are also now accumulating beneath your babies’ skin.

18 weeks pregnant symptoms

If 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 nap may help. Other symptoms that could occur during week 18 include:

Carpal tunnel syndrome

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

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

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

Body aches

Body aches, such as back, groin, or thigh pain, may begin during your second trimester. Your body is rapidly changing. As your uterus expands and pushes 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 them 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. Exercising during the day may also help.

Skin changes and itching

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.

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.

Stretch marks are perhaps the most well-known and common skin change during pregnancy, affecting up to 90 percent of women. Stretch marks 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. Tell your dentist you are pregnant. 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.