We have some good news about Zoloft and two sad truths about medical treatment in general.

The first sad truth affects all medications including Zoloft. Whether they be prescription or over-the-counter drugs, vitamins, health and herbal supplements, or dietary products, they are designed to be absorbed into your blood stream. Once there, the active chemicals go everywhere inside your body. This means that these chemicals circulate through your unborn baby via the umbilical cord. If your baby is born and you are breast-feeding, the chemicals are almost certainly going to be in your milk.

The second sad truth is that illnesses and diseases do not ask when it is convenient to come. They come when they please. Thus, a woman may continue to take a medication for weeks before she realises that she is pregnant. Once you recognise your pregnancy, do you continue to take the medication or, if the illness comes later, do you begin treatment during the pregnancy or while breast-feeding?

Some say knowledge is power. It allows a patient to give informed consent to the treatment recommended by a doctor. In this situation, the question is simple to ask.

"Does taking this medication run the risk of harming my child?"

It is a shame that we do not know more about which medications may be harmful during pregnancy and while breast-feeding.

Although it was more than fifty years ago that thalidomide was first used to treat morning sickness in early pregnancy, the medication's name lives on in infamy. It took until 1961 for doctors to realise that the medication was the cause of major birth defects and it was withdrawn from sale. All prospective parents live with the fear that today's medications may have a similar effect. This fear is not unjustified given a study by Lo and Friedman in Obstet Gynecol (2002). The authors found there is no real evidence as to the scale of risk of birth defects or peri-natal injury arising from the use of almost all the medications approved by the Food and Drug Administration (FDA). What are parents supposed to do? Their decision on whether they may be exposing their unborn child to danger is nothing more than a lottery. This makes a mockery of the doctrine of informed consent.

However, there is some good news. Writing in the New England Journal of Medicine, Alwan, Friedman and others chose to investigate Zoloft and the other Selective Serotonin Reuptake Inhibitors (SSRIs) as the most often prescribed antidepressants during pregnancy. Their results were reassuring, showing no significantly increased risk of birth defects. The women who participated were all taking Zoloft for more than one month before they became pregnant, or took Zoloft during the first three months of their pregnancy. Thus, the mothers were able to take the benefit of effective treatment to control their depressive illness and not harm their babies while in the womb.

It is a medically recognised fact that breast milk is the healthiest food for babies, so women should not stop breast-feeding unless it is absolutely necessarily. A nursing baby will ingest some Zoloft through breast milk, but it is in sufficiently small amounts that it should not affect a baby significantly. However, the latest study did not investigate whether newly born babies were actually affected by Zoloft. This leaves mothers and their medical advisers with a serious lack of information. Babies will benefit if their mothers are well enough to interact positively with them. Given this advantage to both mother and baby, doctors may well treat nursing mothers with Zoloft to give their babies the best nurturing and developmental opportunities.

Millions of prescriptions are written for Zoloft every year yet there is no attempt by the manufacturers or the regulatory authorities to verify Zoloft's safety during breast-feeding. Although the latest news is reassuring and there seems to be no anecdotal evidence to suggest an epidemic of birth defects or injury to newly born babies, it is sad that parents are left to gamble with their babies' safety. Zoloft is a top performing medication. It deserves to have its reputation for safety more formally confirmed.