The health of a pregnant person taking new antipsychotic drugs must be monitored

In a study conducted at HUS, the use of new antipsychotics was associated with an increased risk of gestational diabetes and prematurity. The risk that the baby is born with a large birth weight also increased in relation to the duration of the pregnancy. Previous research results on the matter have been contradictory.

Thanks to the study, we now know that when a person using antipsychotics becomes pregnant

• they have an increased risk of gestational diabetes and associated problems
• blood glucose monitoring is important already when planning a pregnancy
• with clear indications, medication can be used relatively safely.

No change in suitable antipsychotic medication should be made without a specific reason

There has also been a study at HUS on the use of new antipsychotics during the first trimester of pregnancy and their connection to congenital malformations. As a drug group, new antipsychotics have not increased the risk of malformations. From individual medications, the use of olanzapine was associated with an increased risk of malformations, but there were only a few cases and it is likely an incidental finding. Previous studies have not suggested this kind of adverse effect. Olanzapine can still be used during pregnancy when there is a clear indication.

Thanks to the study, we now know that

• The second-generation antipsychotic, olanzapine, is not the primary antipsychotic during pregnancy.
• If olanzapine helps with mental symptoms, use of the drug may be continued. No change in suitable antipsychotic medications should be made without a specific reason
• The use of olanzapine is not a cause for special fetal examination.

Approximately 1.3 million pregnancies were included in the study; the mothers were divided into three groups based on their use of antipsychotics

Approximately 1.3 million pregnancies were included in the study. The study utilized information from a project of the Finnish Institute for Health and Welfare (THL): Drugs and Pregnancy. This is a joint project of the THL, the Finnish Medicines Agency (Fimea), and the Social Insurance Institution of Finland (Kela), in which the information from the Medical Birth Register and the Register of Congenital Malformations (THL) has been combined, as well as information on the reimbursed medicine purchases from the Prescription Register (Kela). In the study, mothers were divided into three groups: users of new antipsychotics and traditional antipsychotics, and mothers who did not use any antipsychotics.

Due to the study results, the health of pregnant people taking new antipsychotic drugs is monitored more closely. On the other hand, the study has also strengthened the perception that new antipsychotics can be used during pregnancy when there is a clear indication.