This image shows a typical chin-on-the-chest position with an arm held up to the side of the face. A knee is just visible to the left of the image with a loop of umbilical cord above it. Your baby now is likely to be in a head down position but there's still time to change.
Most umbilical cords finally grow to be about the same length as the baby (although there are exceptions), reaching a final length of 20-23.5 in (50-60 cm). The umbilical cord has up to 40 turns along its length and these turns are seven times more likely to twist to the left than the right. The coiling pattern was in place nine weeks after conception, with more coils at the baby's end than the placental end; this may be a response to your baby's movements. The cord contains three blood vessels: two arteries taking deoxygenated blood and waste from your baby to the placenta and one vein carrying oxygen-rich blood from the placenta to the baby. The cord diameter is usually less than 3/4 in (2 cm) and the blood vessels are embedded in and protected by a layer of jelly. The watery composition of the jelly, together with the cord's coiling pattern, prevents compression of the cord.
After the birth, your doctor will check the number of vessels in the cord since in 1 percent of singleton pregnancies the cord contains only one umbilical artery.
Some pregnant women experience restless legs syndrome (RLS), whereby they have an irresistible urge to move their legs. It most commonly happens while resting, so can be very disruptive to sleep. The exact cause isn't known but it may be related to an imbalance of a brain chemical called dopamine. The level of dopamine can be affected by a lack of iron. Restless legs syndrome will pass once you're no longer pregnant. To minimize the effects of restless legs syndrome:
A low birthweight is less than 5 1/2 lb (2.5 kg) and although the majority of small babies thrive, some do have difficulties. Most low birthweight babies are small because they are premature. There are many ways you can reduce the risk of your baby being a low birthweight: eating adequate amounts of healthy food to gain the right amount of weight (see How much weight will you gain?), not smoking or drinking alcohol, reducing stress, and keeping all prenatal appointments so that your health-and your baby-can be monitored.
Excerpted from Pregnancy Day by Day.
Copyright Â© 2009 Dorling Kindersley Limited.
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