This is an obvious cause but often overlooked by those trying to begin a family around the age of forty. As a woman passes the age of thirty-five, her chances of miscarrying increase. The reasons are similar to those I have discussed before; they are usually based on chromosomal problems. Abnormalities of the ovum may be involed, for example, or chromosomal problems that would have led to a fetus having trisomy21 (Down’s syndrome), which usually cause miscarring early in pregnancy.
Whether older women, in fact, miscarry more often or whether they report more miscarriages is a debatable point. A younger woman may attribute heavy bleeding one month to a late period, particularly if she did not want to be pregnant. Whereas an older woman, if she has previously been pregnant and has a living child, will more readily recognize the symptoms of pregnancy; she will usually have a strong commitment to being pregnant and will therefore rush to report a miscarriage to her doctor.
There are also surprising statistics for an increased miscarriage rate in very young methers, under the age of eighteen. Why this is so is not known. It could be a reflection of socioeconomic factors; such young women under going pregnancy are more likely to have come from lower socioeconomic classes, with poorer nutrition and general standards of health care. Or, it could be a reflection of the likelihood of first pregnancies to miscarry more frequently.