LONDON — Depression is at least as common during pregnancy as it is after childbirth, and should be diagnosed because it may be harmful to the baby, new research indicates.
While doctors are careful to spot and treat postnatal depression, they are not so vigilant about looking out for depression during pregnancy because they don’t expect to see it, said the study’s lead investigator Jonathan Evans, a senior lecturer in psychiatry at Bristol University in England.
“This will be a surprise to many because most people think that women are protected from depression during pregnancy, that it is a time of emotional well-being,” agreed Dr. Ruta Nonacs, a perinatal psychiatrist at Massachusetts General Hospital in Boston who was not involved in the study. “But this shows that over 10 percent of women have depression during pregnancy – the same as at any point in their lives.”
Previous studies have suggested that depression and anxiety during pregnancy may be linked to low birth weight, premature birth and reduced blood flow in the womb. Evans called for urgent research to clarify the potential consequences to the baby of a mother’s depression during pregnancy.
In the end, it will come down to whether the depression itself, or the drugs used to treat it, are worse for the fetus, experts said.
Postnatal depression is different from the “baby blues,” a transient tearfulness that afflicts most women in the first few days following childbirth.
A more severe mental illness after childbirth called postpartum psychosis, which affects about one in 1,000 women after delivery, can in extreme cases involve mothers harming their children. It usually strikes in the first two weeks to one month after delivery.
In the study, published this week in the British Medical Journal, more than 9,000 British women recorded their moods through pregnancy and after childbirth in a series of questionnaires.
They were assessed for depression at 18 and 32 weeks of pregnancy and eight weeks and eight months after giving birth.
The scientists found that 13.5 percent of the women passed the threshold for depression when they were 32 weeks pregnant, while 9.1 percent scored at that level eight weeks after delivery.
Normally, depression occurs in about the same proportion of women – between 10 to 15 percent of them – at other times of life.
“It’s actually a popular myth that postnatal depression is a specific syndrome,” Evans said.
“Clearly, people do get depressed postnatally. But it has entered public consciousness as a sort of condition somehow separate from the rest of depression and what we are saying is that it is depression like depression at any other time and it occurs no more frequently than at any other time in a woman’s life.”
Although the study found that rates were slightly higher during pregnancy than postpartum, some experts said some cases of postnatal depression may have been missed because the first measure occurred at eight weeks after birth.
“I think there is a syndrome that they’ve missed, that happens much more immediately after childbirth and gets resolved by eight weeks,” said Dr. David Mrazek, chairman of psychiatry and psychology at the Mayo Clinic in Rochester, Minn.
Also, some of the most depressed women dropped out toward the end of the study and did not complete the postnatal questionnaires.
The postpartum figure is an underestimate, but how important an underestimate is unclear, Mrazek said.
“The single most striking thing is this unremitting level of between 8 and 11 percent of young women who come up seriously depressed,” Mrazek said, adding that efforts need to be focused on treating such women to prevent suicide and other complications.
On the Net:
Postpartum Support International, http://www.chss.iup.edu/postpartum/