Change tends to be gradual over a pregnancy—you’re gaining weight steadily and slowly, but it’s not like everything happens all at once. Then one day, maybe right around Week 19, you stand sideways in front of the mirror and wow! You’re looking really pregnant!
Every woman is different, but average weight gain by this point in a pregnancy can be around 15 pounds. Of course that will vary depending on your frame size, if this is your first baby, and your diet and exercise routine. Of the weight you’ve gained so far, about half a pound is your baby; another 6–7 ounces is the placenta; and about 1.5 pounds are uterus and amniotic fluid. Your breasts have also gained some weight and the rest is fluid in the form of increased blood volume and fat stores that will help keep you and your baby nourished and be used to produce breast milk.
The last few weeks have hopefully been fairly free of side effects, aside from the aches and pains that normally accompany pregnancy. You might have also noticed that you get dizzy much easier. This is typically caused by low blood pressure, which means that your brain gets less blood. The two main causes of this are your uterus compressing your aorta when you lay down or what’s known as postural hypotension and dizziness that occurs when you rise from a sitting or laying position too quickly and blood literally drains from your head. The best approach to controlling either type of dizziness is to be gentle with yourself (in the case of postural hypotension, there might not be anything you can do). If you get dizzy when you rise, try going more slowly. And if you do feel dizzy, it’s perfectly okay to sit down and take a break until it passes. Wearing compression stockings or socks give some extra squeeze to your calves and prevent too much blood from pooling in your legs. This can help keep good blood flow to your heart and brain and help with these dizzy spells, too.
If you feel like you could eat continuously, don’t worry: this is perfectly normal at this stage. However, there is one important thing you should be aware of: gestational diabetes. According to the American Diabetes Association, up to 9.2 percent of women develop gestational diabetes, typically in the middle of the second trimester. This condition is caused by excess blood glucose because your body either cannot use all of the insulin it produces or it can’t produce enough insulin to move glucose from your bloodstream into your cells for energy. While we don’t know exactly what causes gestational diabetes, we do know that excessive weight gain and poor diet can increase the risk of it. We also know that gestational diabetes is linked to a host of potential health problems for both Mom and baby.
The opposite of gestational diabetes is hypoglycemia, or low blood sugar. This can be caused by the increased demands your baby and growing body make on your energy supply. Hypoglycemia can make you feel dizzy or shaky. Fortunately, hypoglycemia can generally be corrected quickly be eating something with a quick jolt of sugar, like fruit, and eating a healthy diet of small, regular meals.
Your baby now has a fetal age of 17 weeks. On average, babies at this stage weigh about 7 ounces and measure about 6 inches from the crown of the head to the rump. If you like mangoes, guess what? That’s just about how big your baby is right now.
This is a great time for developing babies. By now, your baby’s proportions have finally become normal. His or her arms and legs are the size they should be relative to the body (although the head is still oversized). If they haven’t already, this is when developing babies begin to put together all of the advances from the past few weeks. The brain and nervous system are fully functioning; the senses are alive and processing all kind of sensory input; and the skeleton is growing stronger by the day. So guess what this means? It’s party time! Babies this age are often working on all kinds of gymnastics, so don’t be surprised if you really start feeling movement now. Punching, kicking, rolling, flipping—it’s all part of the process.
And remember that fine, downy hair called lanugo that started growing a few weeks ago? Right around now, this hair starts combining with a cheesy, waxy substance and dead skin cells to form a thick layer coating the skin called the vernix caseosa. Although it sounds gross—your baby is now basically covered with skin cheese—the vernix serves an important job: it protects your baby’s skin from constant contact with the amniotic fluid. For most babies, the vernix is mostly gone by birth, but some of them are still covered with a white layer at birth, especially if they are premature.
“Fish gets a really bad rap in pregnancy, but is actually super important for your developing baby.”
Reviewed by Dr. Jen Lincoln, November 2018