Week 18 of Your Pregnancy

A look at your body, your baby, and more

week 18 pregnancy highlights


Welcome to week 18 of your pregnancy. It’s hard to believe that you are almost at the halfway point. Even though you and yours have known about baby-to-be for a while, your pregnancy is now more noticeable to those around you.

Your Trimester: Second trimester

Weeks to Go: 22

Verywell Checklist

  • Continue taking prenatal vitamins.
  • Continue drinking about eight to 12 glasses of water a day.
  • Replace everyday heels with more comfortable flats.
  • Begin researching baby’s pediatrician.

Symptoms This Week

If you are a first-time mom-to-be, this may very well be the week that you begin to experience quickening, or baby’s kicks. (Most first-timers notice these early movements between week 18 and week 20.)

Right now, your uterus is continuing to expand, making your pregnancy more and more likely to be visible. At the same time, your growing belly may be starting to shift your center of gravity and cause you to lean forward, which can put stress on your spine.

Also affecting your spine: Relaxin. While its purpose is to loosen hip joints, readying them for delivery, it’s an indiscriminate hormone that can make your spine wobbly right about now, too. (Beware of overstretching muscles and ligaments.)

It’s not uncommon for women to experience low blood pressure (hypotension) during pregnancy, with the lowest dip occurring sometime mid-second trimester. Not only is more blood circulating throughout your system, but hormonal changes are causing blood vessels to dilate, which naturally tamps down blood pressure. This can result in bouts of dizziness.

At the same time, laying on your back can cause your growing uterus to compress the vena cava, major blood vessels in your body. As such, when you sit up, the rush of blood that follows can make you feel lightheaded.

Finally, if you’ve been struggling with hyperemesis gravidarum, which is extreme nausea and vomiting that causes at least 5 percent of total body weight loss, it’s very likely to finally (and thankfully) be gone by now.

Your Baby's Development

Your baby-to-be is practicing his or her napping skills, sleeping and waking throughout the day. And because the bones and nerves that make up the auditory system are nearly complete, loud noises can now wake your baby up. But for the most part, he or she is simply listening to your heartbeat and your blood traveling through the umbilical cord.

At the same time, baby’s retinas may be developed enough to see light. In fact, if you hold a flashlight to your belly, your baby might react to it—a fun, and perhaps first, interaction between the two of you.

Meanwhile, something called myelin—a mix of fatty lipids and proteins that insulate neurons—is starting to form around your baby’s nerves. Myelin plays a key role in the health and function not only of neurons but the brain and the rest of the nervous system, too. Myelin continues to form up until your baby turns one.

If your baby-to-be is a girl, her uterus and fallopian tubes are now formed and in the proper position. If you have a boy on the way, his genitals may be detectable. Either way, he or she will be approximately 6.29 inches long and tip the scale at 5½ ounces by week’s end.

Self-Care Tips

While having low blood pressure during pregnancy is common, there are things you can do to mitigate the lightheadedness that often comes hand-in-hand with it:

  • Get up slowly from a seated or lying position.
  • Avoid standing for long stretches of time.
  • Make sure your showers and baths are not overly warm.
  • Drink plenty of water.

If your back is just now giving you trouble, concentrate on perfecting your posture when standing, sitting, and even sleeping.

  • When Upright: Tilt your pelvis forward, so your lower back doesn’t shift that way. At the same time, contract your abdominals and rear end so those muscles will act as a natural corset, supporting your lower back. (It’s also a smart idea to ditch the high heels for now; they tend to shift your body weight even further forward.)
  • When Sitting: Tuck a rolled-up towel behind your back for support, and use a footrest or stool under your feet to help keep you straight (a stack of books also works in a pinch).
  • When Sleeping: If you sleep on your side, place a pillow between your knees. This will better distribute stress away from your spine.​

A Tip From Verywell

If you're experiencing back pain, work on perfecting your posture when standing, sitting, and even sleeping.

Special Considerations

If you’ve already had a baby who was born with a congenital heart defect; if you or your partner have a family history of congenital heart disease; or if a prior ultrasound identified possible heart abnormalities, your healthcare provider will likely suggest that you get a fetal echocardiogram.

This 45- to 120-minute abdominal ultrasound can be performed as early as week 16 to week 18 of pregnancy. It is typically done by a specially trained technician or a perinatologist, and the images are interpreted by a pediatric cardiologist.

At Your Doctor’s Office

If your healthcare provider offers you a structural ultrasound, also called an anatomy screen or a level II (level 2) ultrasound, it generally takes place between this week and week 20. With this, you likely can learn the sex of your baby or babies, if you want to. At the same time, your healthcare provider will be evaluating how your baby-to-be and placenta are developing.

If you have yet to receive the maternal serum screening test (or the multiple marker test, triple screen, or quad screen), know that this particular blood test is usually done between week 15 and week 18. This test screens for neural tube defects, trisomy 21 for Down syndrome, as well as trisomy 18, which signifies mental retardation.

Upcoming Doctor’s Visits

Your third prenatal visit is coming up. During this, you’ll get the as-predicted urine test, as well as the usual weight, blood pressure, and fundal height measures. As mentioned above, you may also be offered a regular or level II (level 2) ultrasound.

Advice for Partners

There’s lots to prepare for before baby arrives, including interviewing and ​deciding on your baby's pediatrician. You can help start the search by getting some recommendations from other parents or even your own physician.

Many parents like the intimacy and specialization of private pediatric practices, while others value the benefits that come with choosing a pediatrician affiliated with their own medical care facility, such as easier electronic medical record referencing (for family history) and the possibility of scheduling several visits for members of the family all on the same day, in the same place.

When you’ve narrowed your list of candidates, team up with your partner and schedule some preliminary doctor meet-and-greets. At these sessions, you can discuss basic issues such as appointment availability, weekend coverage, hospitals the practice is affiliated with, and what insurance they accept.

But you’ll also want to come armed with more personal questions on topics such as circumcision, vaccination schedules, breastfeeding support, and more. Such meetings are common practice (and free), so don’t worry about pediatricians accommodating or charging for them.

A Tip From Verywell

Now is a good time to begin the search for a pediatrician. Schedule some preliminary doctor meet-and-greets to determine who is the best fit for you and your family.

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Article Sources
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