By Steven Reinberg
The study showed that giving birth in the winter or the spring was linked to a lower risk of developing postpartum depression, as was having a baby at full-term. Using anesthesia during delivery also appears to lower the risk of postpartum depression.
"We wanted to find out whether there are certain factors influencing the risk of developing postpartum depression that may be avoided to improve women's health both physically and mentally," the study's lead author, Dr. Jie Zhou, said in a news release from the American Society of Anesthesiologists. Zhou is from Brigham & Women's Hospital in Boston.
About 10 percent of women suffer from anxiety or depression after childbirth, the researchers said. Symptoms of postpartum depression include sadness, restlessness, agitation and decreased concentration.
Dr. Mitchell Kramer is chairman of obstetrics and gynecology at Huntington Hospital in Huntington, N.Y. He said women who are at high risk for postpartum depression include those who have a history of depression or anxiety, who suffered from the condition after a previous delivery, or who have a family history of mental problems.
Untreated, postpartum depression can interfere with mother-child bonding, the U.S. National Institute of Mental Health says.
Dr. Margaret Seide is a psychiatrist at Staten Island University Hospital in New York City. She said that mothers suffering from postpartum depression are more likely to neglect or abuse their baby.
"Excessive anxiety that's not relieved by visits to their pediatrician, and failure to bond or take joy in their baby are signs of the condition," Seide said.
Treatment is available for women suffering from postpartum depression, Seide noted. These therapies include antidepressant medications and psychological counseling.
For the study, Zhou and colleagues reviewed medical records of more than 20,000 women. All had delivered babies from June 2015 through August 2017. Just over 800 (4 percent) of the women experienced postpartum depression.
The researchers found that being overweight or obese was tied to an increased risk of postpartum depression.
The study wasn't designed to prove cause-and-effect relationships. But the authors have some theories as to why certain factors might influence the development of postpartum depression.
For example, mothers of babies born with a higher gestational age have a lower risk of depression. That may be because the baby is more mature, the researchers said.
"It is expected that the mother will do better and be less mentally stressed when delivering a mature, healthy baby," Zhou said.
White women had a lower risk of postpartum depression than women of other races/ethnicities, which could be due to socioeconomic status, Zhou suggested.
Overweight and obese women often have more complications during pregnancy and need more follow-up after childbirth, and this may account for their increased risk for postpartum depression, Zhou said.
Women who skip anesthesia during labor may increase the risk for postpartum depression, because the pain of delivery might be traumatizing, or women who don't want anesthesia may have characteristics that make them more vulnerable to the condition, the researchers added.
According to Kramer, having or not having anesthesia during labor may be an important factor, especially among women already at high risk for postpartum depression.
"It's not unreasonable to counsel women who are at high risk to minimize the trauma and pain during delivery," he said.
Kramer said he doesn't think that the season in which a baby is born is a significant factor in whether the mother will experience postpartum depression.
"I don't think it's anything that's so significant that I would counsel patients not to have your baby in the summer or fall," he noted.
The researchers suggested that the lower risk of postpartum depression when babies are delivered in the winter and spring may be due to mothers enjoying indoor activities with their babies.
The report was presented Sunday at the meeting of the American Society of Anesthesiologists in Boston. Findings presented at meetings are typically viewed as preliminary until they've been published in a peer-reviewed journal.