The fetus can be seen inside the uterus on this color ultrasound scan. At this stage of development, the fetus measures approximately 2.4 in (6 cm) crown to rump and weighs around 0.3 oz (10 g).
At this stage your baby's heart beats at approximately 140 beats per minute, so at least twice as fast as your own. The heart and its internal electrical conducting system are structurally complete but its external nerve supply is still quite immature. The nerves to the heart influence its rhythm, gradually slowing the rate as the pregnancy advances.
The heart is tiny and to maintain an adequate output the heart is unable to increase the amount of blood it pumps with each beat (as we can), but instead increases the number of times it beats each minute.
The abdominal cavity is large enough to hold the intestines. Whereas before they were bulging outside of your baby's body, they now fit into her abdominal cavity. Having started to rotate while outside the body, the bowel completes its final rotation in the abdominal cavity. Once inside, the bowel position remains fixed, and its diameter increases as the loops of bowel become hollow.
If you're carrying twins, you're likely to have put on some weight by now, perhaps around 11 lb (5 kg). Early weight gain is usually a good thing, especially in your case, since this is a vital time for the formation and development for your babies organs. As a rough guide, a good recommended weight gain is:
If you've only cut down, rather than quitting, read on. Many smokers inhale more deeply when smoking less and their intake of damaging toxins increases. Here's how smoking affects your baby:
Excerpted from Pregnancy Day by Day.
Copyright Â© 2009 Dorling Kindersley Limited.
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