Women who take antipsychotic medication during pregnancy are at no greater risk of developing certain health problems than women who do not take antipsychotics, according to the results of a Canadian study published in The BMJ
on 13 May 2015.
The researchers examined common medical conditions that are magnified by pregnancy and are also associated with antipsychotic drug use — gestational diabetes, hypertensive disorders and venous thromboembolism. They found there was minimal impact on maternal health and perinatal outcomes in women who took antipsychotics compared with women who did not.
“A woman with serious mental illness who discontinues her medication in pregnancy, out of concern for foetal harm, may jeopardise her own mental health and her ability to care for her child after delivery,” say the researchers, led by Simone Vigod, of the Department of Psychiatry, University of Toronto.
The researchers recorded the incidence of the three conditions in two groups of pregnant women of similar age, income and mental health status. The first group of 1,021 women collected at least two consecutive prescriptions for antipsychotic drugs between conception and birth, while the second group of 1,021 women had no exposure to antipsychotics.
Disease incidence between the two groups was similar. Gestational diabetes occurred in 6.1% of women who had not used antipsychotics (non-user group) compared with 7.0% in the group that received at least two consecutive prescriptions for antipsychotics (user group).
Hypertensive disorders occurred in 4.1% of cases in the non-user group compared with 4.7% in the user group. Venus thromboembolism was evident in 1.3% of the non-user group compared with 1.2% of the user group.
There was no significant difference between the two groups of women in the number who gave birth prematurely or who delivered babies classified as underweight or overweight, according to the researchers.
But there were differences between the two groups in the delivery room. More women in the user group had their labour induced compared with women in the non-user group (27.6% versus 23.0%), and the incidence of operative vaginal delivery was higher in the user group compared with the non-user group (9.4% versus 6.2%).
The researchers say their findings are reassuring for women with serious mental illness who have to weigh up the benefits and risks to themselves and to their unborn child of continuing to take antipsychotic medicines when pregnant.
“Antipsychotic medications themselves do not seem to have an extensive negative impact on important measures of maternal medical and short-term perinatal well-being,” they say.
Marjorie Wallace, chief executive of the mental health charity SANE, agrees: “This study should give reassurance to many mothers with bipolar disorder, schizophrenia or other psychotic illness who seek to keep their condition under control with or without medication.”
However, she points out that the study focuses on the effects of use or non-use of antipsychotics pre-birth. “We should not forget the potential effects to a woman’s mental health after their baby is born. A fine balance has to be created and careful decisions made — by both the mother and her doctor — to prevent psychotic relapse.”
Katherine Delargy, deputy chief pharmacist at Barnet, Enfield and Haringey Mental Health NHS Trust, who was not involved in the study, says the perinatal period can be particularly challenging for women with serious mental illness.
“Clinicians and patients should share decision making around the risk of not treating an illness against the risk to the developing foetus,” she adds.