Fetal Development: Week 20

Select Week Number

Week 20 of your Pregnancy

Congratulations! You and baby have reached the halfway mark.

Fetus at 20 weeks gestationBaby is still practicing swallowing and the brain is still continuing to develop.

Your baby may react to loud noises (maybe with a hiccup or two!).

You may notice that baby now has definite periods of sleep and activity.

Your baby now weighs around 11 ounces or 312 grams and is about 6½ to 7 inches or 17 cm long, about the size of an eggplant.

Photo from images.medicinenet.com

What to Expect

Your waistline has pretty much disappeared as your uterus is now around the level of your bellybutton.

You may also find that you are walking a little differently (developing a waddle!).  This is because your center of gravity is changing due to your growing uterus.

If you find that you are more sweaty than usual, it’s because your inner body temperature is up a couple of degrees from normal. Go for comfort rather than “the look”.

If you have suddenly started snoring, don’t panic, estrogen levels during pregnancy causes swelling of the mucus membranes in the nose, so blame it on the hormones!

Are you finding that your usual shoes are feeling too small? Blame those pregnancy hormones again! Many women develop bigger feet during their first pregnancy.

Tip for Week 20

Make sure you wear comfortable shoes so you are stable when you walk.

Measuring your Baby

Physically, the measurement (in centimeters) from the top of your pubic bone to the top of your uterus (the fundus) should correlate with the number of weeks of pregnancy.

On ultrasound, babies are measured from the crown (or top) of the head to the rump (or bottom)(CRL) until about 20 weeks, because the legs are usually curled up. After 20 weeks, they are measured from head to heel (or toe).

Later, the size of your baby will be calculated by combining several measurements in a mathematical formula:

  • Biparietal diameter (BPD) which measures across the head,
  • Head circumference (HC) which measures around the head,
  • Abdominal circumference (AC) which measures around the abdomen and,
  • Femur length (FL) which measures the length of the thigh bone.

This is then plotted on a graph to see whether the fetus is average, larger or smaller in size for its gestational age.


← PreviousNext →