Antibiotic use during pregnancy

DURING pregnancy, the body experiences a number of changes. The most common is that it is more susceptible to infections that are commonly treated with antibiotics. However, obstetrician-gynaecologist (ObGyn) at ICON Medical Centre, Dr Keisha Buchanan, cautions that while most categories of antibiotics are safe for both pregnant mothers and their babies, some are not.

“Many categories of antibiotics are safe in pregnancy, during breastfeeding and safe to newborns. Antibiotics are placed in categories based on their safety. Categories A and B are the safest, Category C is still very safe, as these have no evidence of risk to the pregnancy or the newborn, and are safe during breastfeeding. Categories D and X, however, are always to be avoided,” Dr Buchanan said.

She said that there are virtually no antibiotics available in Category A, hence the vast majority of antibiotics prescribed that are safe in pregnancy are Category B. These include penicillins, cephalosporins and macrolides, and are most commonly prescribed.

Category C antibiotics include fluoroquinolones such as Norfloxacin and Ciprofloxacin, also Gentamycin and Rifampicin. According to the doctor, the fluoroquinolones were placed in Category C mainly because they damage the joints of baby mice in the lab. She explained that there is no evidence to support the risk of foetal damage or miscarriage, stillbirth or birth defects with the fluoroquinolones or other Category C antibiotics in humans, and studies of these drugs in pregnancy have not been conducted.

However, she notes that at times, if the patients have extensive adverse reactions to the Category B medications, and if the pregnant woman has an infection that needs to be treated and will only respond to the Category C medication, then the Category C medication will be used.

Category D antibiotics include the tetracyclines of which Doxycycline is one of the most popular. Dr Buchanan said these must not be used in pregnancy as there is evidence of it causing defects in humans. She said with all tetracycline antibiotics, it should not be used in pregnancy, through infancy and childhood up to eight years of age, as it may disrupt the development of bones and teeth, and may cause babies to develop discoloured teeth, especially if used in the second and third trimesters.

But Dr Buchanan said antibiotics are generally needed in pregnancy to treat common conditions such as bladder, kidney and respiratory tract infections, explaining that the treatment of simple infections can avert more serious complications.

“Pregnant women are more prone to infections, as the elevated hormonal levels during pregnancy weaken the immune system, which is the body’s defence against infections,” Dr Buchanan said. “A bladder infection, for example, can rapidly spread to the kidneys, requiring hospitalisation, as kidney infections are quite complicated. Many other infections can trigger premature rupture of the amniotic membranes as well as premature labour and premature delivery, along with many associated complications.”

She said that antibiotics can also be very effective in the treatment of several infections in newborns such as meningitis, and pneumonia may be prevented by antibiotics administered in labour or after birth to prevent these debilitating infections or even prevent other serious illnesses.

She argues that it is important before any antibiotic is prescribed for a woman that the doctor should find out if she is pregnant or if there is a possibility that she may be.

“A doctor wants to first determine if the woman is pregnant or if she has a delayed or missed period so that a pregnancy test can be done. Also, if the person is trying to get pregnant, this should be stated or the same information should be elicited by the doctor, so as to guide the use of safe medications in case the patient is in early pregnancy,” Dr Buchanan advised.

In instances, for example, where the woman does not know she is pregnant and she may have been prescribed an antibiotic, Dr Buchanan said she need not worry. She warned that getting pregnant is not a reason to stop a prescribed antibiotic, as most of them are safe. Instead, women who find out that they are pregnant while taking antibiotics should seek medical advice if they wish to be reassured.