SSRI Anti-Depressants shown to harm fetus

A US jury’s decision that an antidepressant caused heart defects in an unborn baby is highlighting the painful dilemma facing pregnant women with depression. The most common antidepressants have been linked to birth defects and miscarriage, yet some doctors fear that letting depressive symptoms go untreated may have long-term consequences for the mother and her unborn baby.

On 15 October, a jury in Philadelphia, Pennsylvania, ordered manufacturer GlaxoSmithKline to pay $2.5 million to the family of 3-year-old Lyam Kilker, who was born with serious heart defects. While pregnant, Kilker’s mother took the antidepressant paroxetine (Seroxat or Paxil), which belongs to the most commonly prescribed class of antidepressants, known as selective serotonin reuptake inhibitors (SSRIs).

Doctors try to avoid giving drugs to pregnant women, but Kilker’s mother is not unusual. Antidepressants are increasingly being prescribed during pregnancy, particularly in the US, where 13 per cent of pregnant women took them in 2003.

Risk warning

At the same time, evidence is growing that SSRIs may harm fetuses. While some studies have found SSRIs have no effect, others find that they increase the chance of fetal heart defects and of miscarriage. The most recent study found an increased prevalence of septal heart defects, also known as a hole in the heart, among children whose mothers were prescribed an SSRI in early pregnancy (BMJ, vol 339, p b3569). This was pronounced for two SSRIs, though no association was found with paroxetine. Paroxetine’s label warns that it may raise the risk of birth defects, but in the case of Lyam Kilker, GSK denies its drug was responsible and says it will appeal the ruling: “The scientific evidence does not establish that exposure to [paroxetine] during pregnancy caused his condition.” 

To help doctors and patients weigh up the risks and benefits, in August the American College of Obstetricians and Gynecologists and the American Psychiatric Association released a review of studies examining the effects of taking antidepressants and of being depressed during pregnancy. They concluded that women who get pregnant while on antidepressants should consider switching to psychotherapy, especially in mild cases. They also recommend that doctors discuss the risks and benefits of taking SSRIs with women who become depressed during pregnancy.

David Healy, a psychiatrist at the North West Wales NHS Trust in Bangor, UK, who gave evidence for the Kilker family, told New Scientist that all women of childbearing age, pregnant or not, should be warned about the risks before starting an SSRI, as coming off the drugs can be very hard due to withdrawal symptoms.