Drug prescribing before and during pregnancy in south west France: a retrolective study

Several drugs that are known to exhibit teratogenic or fetotoxic risks when used during pregnancy should not be prescribed to pregnant women. However, most women of childbearing age use medications, and drug use cannot always be avoided during pregnancy, especially for women with chronic diseases for whom the benefit of treatment outweighs the potential risk of the drug for the fetus. Nevertheless, it is often possible to replace a drug with another one that has been better evaluated.

The aim of the present study was to describe the prescribing of drugs to pregnant women before and during pregnancy in order to examine whether the occurrence of pregnancy modifies drug prescribing and dispensing to women. In particular, drugs that are contraindicated or must be avoided during pregnancy, such as retinoids, ACE inhibitors, angiotensin II receptor blockers, NSAIDs and valproic acid, will be analysed.

This retrolective study used data already prospectively recorded in the database of the French Health Insurance Service. It analysed pharmacy records of women who gave birth between 1 January 2007 and 31 December 2007 in Midi-Pyrenees. Pharmacy data were analysed from 9 months before pregnancy until delivery. Drugs were classified according to the Anatomical Therapeutic Chemical code.

The study included 23 898 women. Approximately 77% and 96% of the women received at least one prescription before and during pregnancy, respectively. The number of women who were prescribed contraindicated drugs significantly decreased with pregnancy (p < 0.0001). Most of the drugs were stopped during the 3 months before pregnancy without alternative treatment, even for chronic diseases. However, for some women, potentially dangerous prescriptions were maintained during pregnancy, and for others these drugs were dispensed for the first time during critical periods of pregnancy.

Despite recommendations, some teratogenic and/or fetotoxic drugs are still prescribed and dispensed to pregnant women in France. There is a need to repeat information to sensitize health professionals and women to the harmful potential of drugs. Moreover, discontinuation of a needed treatment must be avoided. Therefore, attention must be given to ensuring that younger females and women of childbearing potential who are likely to need continued treatment in adolescence and adulthood are aware of the potential risks that some drugs may pose during pregnancy.