Fibroids are rarely connected with pregnancy because the majority of women who become pregnant are under 30 whereas the majority of women who suffer from fibroids are over the age of 40. However, a few younger women do have fibroids, some of which occasionally interfere with the normal progress of a pregnancy.
The majority of fibroids are of no significance and have no effect upon a woman’s fertility, her pregnancy or delivery. Some, however, impinge upon or distort the actual cavity of the uterus and may cause complications in pregnancy, as may a very large fibroid which by virtue of its size distorts the uterus and the other pelvic organs.
Fibroids that distort the cavity of the uterus and very large fibroids may occasionally cause infertility and, if this is considered to be so, they can be removed by an operation known as myomectomy in which the fibroids alone are removed and the conserved uterus is then carefully reconstructed. Similarly if it is considered that fibroids predispose a woman to recurrent or habitual abortion they are removed by myomectomy. Large fibroids may be responsible for the onset of premature labour.
This is unusual, however, because they must be at least 10 cm. in diameter to have this effect. They may occasionally predispose to an extra amount of bleeding after the baby has been delivered. The presence of such fibroids, however, is always known beforehand and precautions can be taken which will usually prevent any postpartum haemorrhage.
Abnormal Presentation of the Foetus
This is unusual but is a possibility where a very large fibroid is present in the lower part of the body of the uterus. Since there is no room for both the fibroid and the baby’s head in the lower uterine segment, the baby’s head is pushed to one side and does not present normally. This usually resolves itself spontaneously before the onset of labour because, with the stretching of the lower part of the uterus and formation of the lower uterine segment, the fibroid is drawn further up into the abdomen and the baby’s head can descend into the pelvis. If the presentation does not correct itself spontaneously, the baby is delivered by Caesarean section. The fibroid may be removed at a later operation, if this is necessary, but it is not usually removed at the time of the Caesarean operation because of the danger of haemorrhage from the extremely vascular pregnant uterus.
Red degeneration is a strange and peculiar condition in which a fibroid becomes very acutely inflamed. This usually happens about the middle of pregnancy and the fibroid suddenly becomes extremely tender and painful. The amount of pain can be very considerable and it can be very difficult to arrive at an exact diagnosis. The treatment is admission to hospital, rest in bed, sedation and pain- killing drugs.
The pain passes off spontaneously in about 48 hours after which the fibroid gets rapidly smaller and will never again cause trouble. It may be very difficult to differentiate between red degeneration and acute appendicitis. Because the danger of ignoring acute appendicitis is so great it may be necessary to operate in order to be certain of the diagnosis. If it proves to be red degeneration, the fibroid will be left in place and the abdominal incision closed without anything farther being done. The disastrous consequence of failing to remove an acute appendix more than justifies the occasional ‘unnecessary’ operation.