Foetal distress

When foetal distress occurs, the foetus lacks oxygen and nutritional elements necessaary for harmonious development. Such distress is manifest by a change in foetal heart rate. Foetal distress can develop in late pregnancy and then become "chronic." It is caused especially by hypertension in the mother or by a retroplacental hematoma; each case requires individual management.

When pregnancy continues past 42 weeks (postmaturity), the physician must monitor the patient carefully: at such a time, the placenta begins to function less efficiently; supplies of oxygen and food become inadequate, and can results in foetal distress. The most common cause is compression of the umbilical cord to a variable extent during delivery. Before the baby is born, he is free to rotate around the umbilical cord which may go around his neck or his shoulder in suspender-like fashion; during contractions of the uterus, there is decreased oxygen to the foetus and the heart rate slows, all the more so if the cord is tightly wrapped around his neck.

Foetal heart rate

It is obvious that slowing of the foetal heart rate of short duration during a contraction of the uterus and its rapid return to a normal rate correspond to a temporary restriction of oxygen only; on the contrary, a prolonged decrease in heart rate after a uterine contraction leads to suspect foetal distress. Thus, the physician bases his judgment on the monitor tracing and any flattening in the curve to accelerate delivery or, if necessary, to extract the baby by caesarean section.

Currently, in some cases physicians can prescribe medications which cross the placenta and regularise the foetal heart rate; such treatment will be continued after the baby is born. Some types of anemia can also be treated in utero with transfusions through the umbilical cord. These drugs thus help prevent foetal distress.