Some are preventable, while others can be treated without any risk to the foetus.

IT is not uncommon to get infections during pregnancy. They can be respiratory or urinary tract infections which are treatable and curable, and don’t cause any untoward effects on the mother and foetus. However, there are infections which are not as common but have effects on the mother and/or foetus.

It is important to inform the doctor if one is pregnant, particularly in early pregnancy. This is because there are medicines that cannot be prescribed or have to be taken with caution when pregnant.

Risky: If a woman gets an infection during pregnancy, it is wise to treat it immediately or risk passing it on to her baby.

Urinary tract infections

Urinary tract infections (UTIs) are common in pregnancy and are usually due to bacteria. UTIs are more common in women because of their short urethra and its proximity to the vagina and anus. There is loss of tone in the ureters during pregnancy due to the effect of progesterone produced by the placenta. This and the increased urine production lead to the collection of urine (stasis) which predisposes pregnant women to UTIs especially infection of the upper urinary tract and kidneys (pyelonephritis).

UTIs, if not treated adequately, will cause complications, i.e. dehydration, pyelonephritis, kidney and blood dysfunction, lung injury and septicaemia. Complications in the mother will have consequences on the foetus.

UTIs can occur with or without symptoms. About 5% to 10% of UTIs are without symptoms, while symptoms include pain on passing urine (dysuria), increased frequency and passing urine at night (nocturia). If the kidneys are affected, there may be fever, chills, shivering, nausea, vomiting or pain in the flanks.

The urine is analysed at every antenatal visit. If there are any abnormal findings or there are symptoms, it would be sent for culture of organisms.

When there is a UTI, appropriate antibiotics will be prescribed together with fluids, if there is dehydration. Hospitalisation will be advised if there is evidence of pyelonephritis.

There are usually no complications of UTIs provided there is compliance with appropriate treatment.

Group B Streptococcal infection

Group B streptococcus (GBS) is a bacterium that is normally found in the body, including the vagina and rectum. It is found in the vagina in about 25% of pregnant women. The foetus can get infected during labour and delivery. Most babies do not get infected but a few do. About one in 10 of those who get infected die, making GBS the most common cause of life-threatening infection in a newborn.

Babies with GBS have clinical features that include floppiness, unresponsiveness, poor feeding, grunting, irritability and changes in heart and respiratory rates. The features appear within 12 hours after birth. Babies who have features of GBS will be prescribed antibiotics. If untreated, the babies may get seriously ill and even, die.

A baby is at increased risk of GBS if it has been detected in the urine and/or high vaginal/rectal swabs; a previous baby had GBS; there is fever, pre-term labour (before 37 weeks); or the membranes have ruptured for more than 18 hours. In such circumstances, penicillin will be prescribed during labour to reduce the risk. If there is allergy to penicillin, an alternative antibiotic will be prescribed.

If the swab shows GBS, antibiotics are not prescribed if there was GBS in a previous pregnancy and the baby was unaffected; during pregnancy unless there are symptoms of infection e.g. UTI; before the membranes rupture or when an elective Caesarean section has been planned. Antibiotics are not prescribed in such situations because the risk of GBS is low and they do not reduce the chances of getting GBS during labour.

Breast feeding does not increase the risk of GBS infection. Moreover, breast feeding protects the baby from other infections.

Genital herpes

It is caused by a virus called herpes simplex, of which there are two types, i.e. types 1 and 2. It affects the area in or around the vagina, the vulva and anus.

At the time of the initial infection, there may be painful sores or watery blisters in the pubic area, vagina, vulva or anus, and pain on passing urine. One may feel unwell with fever and tiredness. After the initial infection, the virus stays in the body and can be activated repeatedly. A warning sign of activation may be a tingling sensation in the affected area.

Herpes can spread even if there are no symptoms. It is spread by skin-to-skin contact with a herpes sore; vaginal, oral or anal sex; sharing of sex devices with someone who has genital herpes; oral sex with someone who has a cold sore; and from mother to baby during birth.

It is most likely to be spread when symptoms appear, or just before that. The sores or blisters are highly infectious. It is possible, but not common, for an infected person to spread the infection to the baby during labour. If the baby is infected, the skin, eyes, mouth, brain or other organs can be affected. Sometimes, the baby may become very ill or even die. Medication may prevent or reduce long-term adverse consequences on the baby.

However, most women with genital herpes deliver healthy babies. The foetus is usually protected by the mother’s immunity, i.e. antibodies developed in response to previous infections are passed on to the foetus. The antibodies are usually retained by the baby for up to three months after birth.

If the initial genital herpes occurred before pregnancy and there has been no activation during pregnancy or labour, it is very unlikely for it to spread to the foetus. If the herpes occurred before and is active when in labour, the risk to the baby is still very low.

If the initial infection herpes occurred in late pregnancy, there is insufficient time for antibodies to develop and pass on to the foetus; hence the risk of the baby getting infected is higher. About 40 out of 100 women who have a vaginal delivery at the time of infection spread the virus to their babies. The risk is highest if the baby is born four hours or more after the membranes have ruptured.

If your spouse has herpes but you do not, or if you are unsure, the risk of getting the infection may be reduced by avoiding sexual intercourse or oral sex whenever he has an activation of the infection. Condom usage throughout pregnancy is useful in reducing the risk of spread.

It is essential to avoid skin-to-skin contact between the baby and anyone with an active infection.

If genital herpes is suspected, the doctor will provide appropriate investigation, treatment and support. Checks for other sexually transmitted infections will also be made.

An antiviral medicine, acyclovir, will be prescribed if there is an initial infection when pregnant, to reduce the duration and severity of the symptoms; if there is an initial infection in late pregnancy, to prevent activation during labour; or if there is a repeat activation while pregnant, especially in the last three months of pregnancy.

There are no reports of adverse consequences to the foetus when acyclovir is taken during pregnancy. There are no side effects in most women.

The obstetrician will advise delivery by Caesarean section if there is an initial infection in the last six weeks of pregnancy or if there is an infection when the patient is about to go into labour or deliver. This reduces the risk of spread to the baby during the birth.

A Caesarean section is not advised if the initial infection occurs in the first six months of pregnancy The obstetrician will discuss the risks of having a Caesarean section and the likelihood of foetal infection and its consequences.


It is caused by a virus and is spread by airborne droplets when an infected person coughs or sneezes. After getting the infection, the virus spreads throughout the body in five to seven days. It is usually a mild childhood condition with about 20% to 50% of patients having no symptoms at all. The rash, which lasts about three days, often starts in the face and spreads from the head to the feet. There may be low-grade fever and swollen neck lymph nodes.

Complications are uncommon and occur more in adults than in children. There is arthritis in about 70% of infected adult women, usually involving joints in the fingers, wrists and knees. Bleeding occurs in about one in 3,000 cases and is more common in children. Encephalitis occurs in about one in 5,000 cases and is more common in adults.

In the first three months (trimester) of pregnancy, the foetus has a 90% chance of getting infected. Congenital rubella syndrome (CRS) is an important cause of severe birth defects or foetal death. Deafness is most common but it also causes defects of the heart, eyes and brain. The infant with CRS may not have symptoms for two to four years, and may transmit the virus for a year or so.

There is no specific treatment for rubella. The treatment is symptomatic, i.e. plenty of fluids, medicines for fever or arthritis.

Rubella vaccines are effective and safe. They are usually given in combination with measles and mumps vaccine (MMR).

Source: Dr Milton Lum