The information has been gathered from the registers of births and dispensed drugs in Denmark, Finland, Iceland, Norway and Sweden. The study is presented in the medical journal JAMA, and is the largest of its type carried out.
Previous studies have shown that pregnant women who take anti-depressant drugs from the SSRI group run an increased risk of having children with certain uncommon birth defects and infant diseases. The studies have shown that certain SSRI medicines are associated with, among other conditions, heart defects in the infant. In the case of all SSRI medicines, newborn infants may experience temporary withdrawal problems, which are expressed in such symptoms as increased irritability, sleeping difficulty and difficulty with breast-feeding. Persistent pulmonary hypertension is also more common in babies whose mothers have taken SSRI drugs during the pregnancy. This is a serious condition in which the blood of the newborn is not properly saturated with oxygen after delivery.
It has not, however, been known how stillbirth and infant mortality are coupled to the use of SSRI drugs. Scientists at Karolinska Institutet have now participated in a Nordic collaboration, and followed up more than 1.6 million births in the period 1996-2007, using the national registers of birth and prescribed drugs. The results show that 1.8%of pregnant women took out a prescription for SSRI medication at least once during a period that stretched from three months before they became pregnant until the delivery. It was more common for older women and women who smoked during the pregnancy to have taken these drugs.
Just over 6,000 stillbirths occurred during the period that was investigated, while just over 3,600 newborns died during the first month of life. A further 1,500 died during the first year of life. Deaths were somewhat more common among women who had taken SSRI drugs during the pregnancy. However, when the statistics were adjusted for the mental health of the mothers, their higher age, the tendency for them to be smokers and the greater incidence of diabetes and high blood pressure, it was no longer possible to see a coupling between the SSRI drugs and increased stillbirths or infant mortality.
“We have shown that the risks of stillbirth and infant mortality are not higher when a woman takes an SSRI drug for depression. There are, however, risks of serious adverse effects for the baby, while there are at the same time well-known risks of failing to treat depression in pregnant women”, says Olof Stephansson, Associate Professor at the Clinical Epidemiology Unit, Department of Medicine, Solna.
These include the risk that the depression will become more severe, with an accompanying risk of the mothers suicide during the pregnancy and period after the birth. It is also known that the growth of the foetus may be poorer, and that the risk of premature labour is greater, if a severe depression is left untreated.
“It is important to make a considered individual assessment in each case, in which all known risks for the mother and the baby are weighed up, when deciding whether to treat a pregnant woman with SSRI drugs. The doctor should review the medication taken by the pregnant woman against depression in order to select the right drug and dose. It is also important to follow such women carefully during the pregnancy and breast-feeding period”, says Olof Stephansson.
The study has been financed by what was then Apoteksbolaget, now Apoteket AB, a company owned by the Swedish government, together with funds from the Swedish Society of Medicine. The study was performed at Karolinska Institutet in collaboration with researchers from the following Organizations/Universities: the Nordic School of Public Health, Gothenburg, Sweden; THL National Institute for Health and Welfare, Helsinki, Finland; Institute of Public Health Oslo, Norway; University of Bergen and Tromsø, Norway; Aarhus University, Denmark; University of Iceland; Harvard University, and Mount Sinai School of Medicine, USA.
Selective Serotonin Reuptake Inhibitors During Pregnancy and Risk of Stillbirth and lnfant Mortality
JAMA, Journal of American Medical Association, online 2 January 2013, Vol. 309, No 1