Your Pregnancy Week 16

Reviewed by James Brann, MD
Learn about your symptoms and changes during the 16th week of pregnancy.

Your Baby

By pregnancy week 16 your baby is more than 4.5 inches long and may weigh almost 3 ounces.

Changes in Your Growing Baby

Your baby is planning on a huge growth spurt in the upcoming weeks. Your baby has grown strong enough to hold his head straighter. Your baby's eyes and ears are moving into their final position and your baby is focusing much of her energy on her circulation system. By now your baby's heart is pumping roughly 25 quarts of blood each day!
Your baby starts growing fine hair on the top of his head, though some babies will be born very bald despite their best efforts. The color of your baby's hair and even your baby's eyes may change shortly after birth. Many babies are born with blonde hair for example that falls out and turns brown a short time after birth. Still others are born with brown eyes that turn blue within a month or two after birth! Your baby will continue to amaze you in the weeks following pregnancy.

As you continue your pregnancy week by week your baby's legs start lengthening.

Your Body's Development

You can proudly boast a small belly. You may find you temporarily miss your waist, but remember that will come back just a short time after delivery. Many women love this stage of pregnancy where they are just big enough to look pregnant but not so big they feel bulky and clumsy.

By this time you might start needing some maternity clothes. While you may not fill them out entirely for a couple more weeks, you may still be more comfortable wearing something that gives you room to grow. Most of the time your maternity size corresponds to your pre-pregnancy size. Most maternity clothes come in small, medium, large and extra-large sizes.

Changes in Your Body

Most women report their favorite part of pregnancy is feeling their baby move inside them. By now you might start feeling little fluttering in your stomach for the first time. This sensation may be gas, but in many cases this far along it is often your baby's way of saying hello! Most babies are enjoying the vast amount of space they have to move around the uterus, thus swim about vigorously. This can result in a variety of unusual sensations in your lower abdomen.

In the second trimester of pregnancy you will undergo certain tests at your doctors office, including at 16 weeks pregnant to 18 weeks, the alpha-fetoprotein test or AFP test. This is a test that measures the protein coming from fetal urine. This test can indicate if a potential problem may exist with your baby. A higher level of AFP for example may suggest that your baby is at an elevated risk for certain central nervous system or spinal cord problems. Some baby's with an elevated AFP are more at risk for Down Syndrome. If you do have an elevated AFP don't panic. It may be nothing. There are many false positives. In many cases however your doctor will recommend an amniocentesis or ultrasound to confirm whether or not a problem may exist.

An amniocentesis is a test that looks for chromosomal problems or genetic birth defects in babies. During this test a health care provider passes a thin need through the uterus to withdraw amniotic fluid for testing. There is some risk for miscarriage, leaking or complications from this test. You should talk with your doctor thoroughly before deciding whether you want this test as it is somewhat risky.

Fetal Movements

Sometime between 16 and 21 weeks pregnant, you will start to feel your baby move inside your belly. These subtle first kicks may feel like fish swimming in your stomach or butterflies. Some women even confuse them with hunger pains or gas.

If you've never been pregnant before, you may not realize what you're feeling is actually your baby for several more weeks. First-time pregnant women don't notice their baby's first kicks until around 18 to 21 weeks pregnant. For second-time mothers, you might feel the first fetal movements earlier - possibly as early as 16 weeks pregnant.
It's probably too early for you to start keeping track of your baby's kicks. Fetal movements are not strong enough yet. Your baby is indeed moving around, kicking and punching plenty, you won't always feel them. But once your baby's movements become more regular and they get stronger in the latter part of your second trimester, you'll want to pay attention to them. Let your doctor know right away if you notice a decrease or a change in your baby's activity level. This might signal something is wrong.

Until your baby's movements are strong enough, enjoy spending this time with your developing baby. Relax and enjoy your second trimester.

Video: What to Expect from the 16th Week of Pregnancy



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