How babies may be more vulnerable to medication

New research has found a mechanism that suggests that some fetuses and newborns exposed to paracetamol may experience untoward effects. The experimental approach used is now being applied to other drugs that may be taken during pregnancy and after, providing a pathway to better understanding of what is a safer dosage for pregnant and breastfeeding mothers. This is particularly important where it is essential that mothers continue treatment in order to avoid adverse effects from discontinuation of therapy on themselves and their babies, for example anti-epileptic drugs.

Paracetamol (acetaminophen) is widely used in pregnancy and generally regarded as "safe" by regulatory authorities.  But what do we actually know about the risk to unborn babies when the mother takes a medication?  It remains the most commonly administered drug in the world.

In a second major paper written by Professor Norman Saunders from the University of Melbourne's Department of Pharmacology and Therapeutics Research and colleagues, have shed important more detail on a new area of investigation to better inform the safety of medications for the unborn baby during pregnancy and newborns during breastfeeding. The Australian Medicines Handbook (2019) states without qualification that paracetamol is "safe for use in pregnancy and breast-feeding".

The research shows that is it possible to assess how vulnerable fetuses and newborns are to drug entry across the placenta or via breastmilk into the developing brain, and so eventually contribute to development of appropriate guidelines for taking medications when pregnant and thus better protect both babies and their mothers.

The study, published in F1000Research, focused on paracetamol, which is taken by an estimated 65 to 75% of women during pregnancy.