Pregnancy and Disease Infections

One of the main aims of antenatal care is the early detection of any health problems that already exist or appear for the first time during pregnancy. Such problems may be infections or illnesses such as diabetes, heart or lung disease. Some diseases – like rubella (German measles) – are rarely threatening to the mother but may have grave effects on the baby. In other instances a disorder may reduce the ability of the mother to withstand the strain of pregnancy and labour.

In general a disorder in pregnancy needs treating as carefully as possible. Optimal antenatal care often succeeds in making the risks for both mother and child as low as those for an uncomplicated pregnancy.


Ideally, a woman should ensure that she is immune to rubella before becoming pregnant. Younger generations of women are now being immunized in early adolescence before they reach childbearing age. Women who have missed out on this injection and who did not have rubella as a child, can obtain immunization through their family doctor. It is important for the woman not to become pregnant for three months after the injection because there is a risk of congenital damage.

If a woman becomes pregnant before being immunized and then contracts rubella during the first 12 weeks of pregnancy, there is a risk that the baby will be born with congenital defects of the eyes, ears, heart or other organs. The risk may be as high as 50 per cent if the infection is contracted during the first four weeks of pregnancy. The defects vary according to the organs that are developing at the time. Maternal rubella infection is accepted as grounds for termination of pregnancy in most countries where abortion is legal.

Sexually transmitted diseases

Because syphilis in women is often without symptoms, a routine blood test is performed at the first antenatal examination in order to identify the few women who have the disease. The organism that causes syphilis crosses the placenta and infects the foetus. This infection can cause the death of the foetus from congenital syphilis. This can be completely prevented, however, if the infection is treated with antibiotics early enough in pregnancy.

Gonorrhoea is another sexually transmitted disease that can be potentially harmful to the baby. If this infection is allowed to persist until delivery, it will probably be transferred to the baby’s eyes during birth.

To prevent such a conjunctivitis, in some countries every baby is treated with eyedrops which kill possible causative organisms.

A third sexually transmitted disease is genital herpes. If this recurrent disease is active at the time of birth, the infection, which occurs on the surface of the vulva, may be transmitted to the baby and can be fatal.

If a woman or her partner has had a vesicular eruption on their genitals they should inform their doctor. If tests carried out in the last weeks of pregnancy show that the virus is active, the baby will be delivered by Caesarean section, to prevent it from being infected.

Other infections

Maternal infections with cytomegalovirus or the parasite which causes toxoplasmosis have been shown to cause congenital abnormalities. However, the chances of the mother acquiring either disease for the first time during early pregnancy are extremely small. Other viruses such as measles, chickenpox and mumps will not harm the foetus, although if the

woman contracts them late in pregnancy the baby may be born with the illness.

Any very severe infection early in pregnancy may cause miscarriage.

Benign vaginal infections such as Trichomonas and thrush (Candida albicans) are harmless to the baby and can be easily treated.

In the case of thrush, the baby may pick up the infection in its mouth during delivery, but again, this is easily cured.