Women who continue to experience pain from childbirth one month after having a baby may be more likely to develop postpartum depression, a new study suggests.

Specifically, researchers found that women in Singapore who had pain that lasted longer than four weeks after they gave birth had higher scores on tests that measured the women's risk for postpartum depression. This was compared with both new mothers who had no pain following delivery and with women whose pain resolved by four weeks.

The findings suggest that persistent childbirth pain in women is linked with a greater risk for postpartum depression, said Dr. Ban Leong Sng, the senior author of the study and the deputy head of the department of women's anesthesia at KK Women's and Children's Hospital in Singapore. 

The exact mechanisms to explain the link between persistent childbirth pain and postpartum depression are still being investigated, Sng said. However, possible explanations could include genetics, hormonal influences, and an association between psychological vulnerability to both depression and pain, he suggested.

The researchers presented their findings this week at the World Congress of Anesthesiologists in Hong Kong, but the results have not yet been published in a peer-reviewed scientific journal. 

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In the study, the researchers collected data from 200 healthy women in Singapore who were giving birth for the first time. All of the women received an epidural for pain relief during labor and delivery.

During their pregnancies, the women completed tests to rate their perceived level of stress and sensitivity to pain. Six to eight weeks after giving birth, each woman was interviewed by phone to evaluate her level of anxiety, determine whether she was experiencing persistent childbirth-related pain and assess her risk of postpartum depression.

The researchers found that 5.8 percent of the women in the study reported having symptoms four weeks after giving birth that suggested they were at risk for postnatal depression. This rate is lower than researchers expected, said Dr. Helen Chen, a co-author of the study and a senior consultant in the department of psychological medicine at KK Women's and Children's Hospital in Singapore.

This lower rate of postpartum depression may have resulted because the sample consisted of healthy women who had received epidural pain relief, rather than women in the general population, Chen told Live Science. Those other women may or may not be as healthy and might not have received similar or any form of pain control during childbirth, Chen said.

Worldwide, the prevalence rate of postpartum depression is generally between 10 and 15 percent, according to the study. 

But the research findings support the need to address pain comprehensively to lessen a woman's risk of developing postpartum depression, Sng told Live Science. To do this, anesthesiologists can better address childbirth pain through their evaluations and treatment of the condition during and after labor and delivery, he said.

To ensure their physical and emotional well-being, women should receive both a pain evaluation and a screening for postpartum depression after they deliver, Sng said.

Getting a good start

The link between postpartum depression and pain during delivery and after childbirth is an incredibly neglected area of research, said Dr. Katherine Wisner, a perinatal psychiatrist who directs the Asher Center for the Study and Treatment of Depressive Disordersat the Northwestern University Feinberg School of Medicine in Chicago.

The newest and most intriguing piece of data provided by this study concerned the Edinburgh Postnatal Depression Scale (EPDS) score, a screening tool used worldwide to measure a woman's risk for postpartum depression, said Wisner, who was not involved in the study. This scale was found to be closely related to the duration of a woman's childbirth pain, Wisner said.

Moreover, the researchers showed that the longer a woman's pain went on after childbirth, the greater was her risk of having a higher score on this screening exam for postpartum depression, Wisner told Live Science.

Women who reported never having any childbirth pain after delivery scored, on average, 4 points lower on the depression screening than women whose pain lasted more than 4 weeks, she said. Meanwhile, women whose pain resolved within four weeks scored, on average, 2 points lower on the postpartum depression screening than women who had childbirth pain lasting more than 4 weeks, Wisner said. A lower score means a lower risk for postpartum depression.

The study shows that it's very important to get women off to a good start after they give birth, Wisner said. This good start helps a woman gain more confidence and develop her sense as a mother, Wisner explained. If a woman is impacted by a cascade of negative things right after giving birth — uncontrolled pain following a C-section, pain during breast-feeding, or pelvic pain, for example — she does not get off to a good start, Wisner said.

Women can be assertive with their health care providers about the pain they may be feeling postpartum, she said. Thinking that it's normal to have pain that lasts can be detrimental, Wisner added .

Pain after childbirth should be a variable that women's health care providers watch carefully, Wisner said. Most women do well with standardized pain management after giving birth, so speaking up about feeling uncomfortable can help get pain under control early so it might not linger, she said.

More attention needs to be paid to the control of childbirth pain, because it is one of the modifiable factors that can reduce the risk for postpartum depression, Wisner said. And more long-term studies of persistent childbirth pain are needed to see if some of these women go on to develop chronic pain, she said. 

Originally published on Live Science.

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