Pregnancy Week 20 – The Baby’s Progress

At pregnancy week 20 your baby’s heart will still be beating at twice the rate of yours (around 140 beats/minute compared to the normal 70) and this will be closely monitored on every hospital visit from now on. Your baby’s heart beats much faster due to its compact size and because it needs to provide enough deoxygenated blood for gas exchange to take place in order to provide oxygen to the relatively few air sacs available in the lungs. While her heart will be monitored regularly, other reasons your baby is scanned is to also check her position in the womb, see how your placenta is developing, along with her growth rate and whether or not she may or may not have any congenital defects.

Pregnancy at 20 weeks – How to use a heartbeat monitor

Scanning has no known risks to either mother or baby because the sound waves used are of such low density that they can safely be performed on a repeated basis. You can even use your own doppler device at home to hear your baby’s heartbeat as often as you like. The video above shows how to use one yourself.

As a 20 week fetus she will now be bigger than her placenta, although the placenta is now technically fully formed it will still continue to increase in size. Your baby’s bones will remain malleable up until birth, however, they will go through enough hardening to ensure she has a safe delivery. In order to do this she will stretch, kick, punch, somersault, grasp and turn in between her own sleep cycles. This will not only aid muscle growth, as her nerve fibres are now all connected, but it will also improve her motor ability.

Although the formation of your baby’s inner ear would have began developing as early as the fourth week, the inner ear bones will continue to solidify as her hearing begins around week 22. The ears develop in three parts; the internal, middle and external ear. The external ear shows very basic signs of being present from 6 weeks onwards. The cartilage in the ear is very soft to begin with and if the baby is born prematurely then the degree of softness is an indication of how premature the baby is.

As all 5 senses have matured, the taste buds can now distinguish between bitter and sweet. The taste of anything you eat from now on will be transferred through to the amniotic fluid. Babies will quite often tend to like the foods that their mothers have enjoyed during pregnancy. While brown fat has developed around the neck, kidneys, groin and behind the breastbone, white fat will continue its placement around the rest of the body until birth, in order to gain weight.

Pregnancy 20 weeks will now show your baby measuring around 6.5” (16.5 cm) and weighing approximately 10 oz (283 g).

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(See 20 Weeks Pregnant – The Mother’s Progress)


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