The majority of mothers over the age of 35 who become pregnant can expect a normal pregnancy and a healthy baby. However, older mothers are at greater risk of developing complications. For that reason, an older mother is screened to detect these at an early stage. Older mothers are also at higher risk of having a baby with disabilities, so most are eager to take advantage of the screening tests available.
There can hardly be a mother who has not worried at some time in her pregnancy whether her baby will be normal, and this may be particularly true for the older mother. Fortunately, a number of screening tests are now offered to women at higher risk of having a baby with severe problems. These tests can be very important in easing the parents’ worries. In cases where an abnormality is shown, the screening enables them to decide whether or not to proceed with a pregnancy. However, it is important to remember that not all abnormalities can be detected in pregnancy and that accidents at birth can also lead to disabilities. The tests eliminate certain problems but do not guarantee the “perfect baby.”
How the Baby Develops
A human embryo is more or less completely formed by the end of the twelfth week of pregnancy. After this time it simply has to grow in size and its organs have to mature to make it capable of living outside the womb. All the major developments take place in the early weeks of pregnancy, which is why it is especially important to look after yourself before you even know you are pregnant. The baby’s spinal column, for example, begins to form in the fifth week of pregnancy. You are likely at this stage to realize that your period is late, but have not had the pregnancy confirmed. In the sixth week arm and leg buds are formed. In the seventh week the beginnings of the fingers and toes are visible and dramatic changes are occurring to the head and face. In the ninth week the nose and mouth take shape. By the eleventh week the genitals are formed, and all the internal organs are functioning.
Abnormalities in a baby are usually caused by genetic problems or by an environmental influence, such as poor diet, the use of drugs in early pregnancy or by hazards in the workplace, such as toxic chemicals or radiation. Genetic problems fall into two categories: those caused by either or both parents carrying a faulty gene, or those that occur when the sperm or egg are formed. In the second case, the formation involves an extra chromosome or part of a chromosome being included in the fertilized egg.