Risk Factors for Developing Dysphoric Milk Ejection Reflex

Dysphoric Milk Ejection Reflex (D-MER) is a prevalent, yet under-researched disorder in affecting lactating women. It is typified by sudden and intense feelings of negative emotions like anxiety, anger, or sadness, which occur during the milk-let down reflex. Usually, there is no dysphoria during the time between episodes. 

The researchers conducted a cross-sectional study using an online survey of lactating parents with children under 18 months old who had nursed for any duration. Participants were not pre-selected based on awareness of D-MER, and recruitment did not reveal the survey's specific focus. They also analyzed risk factors for developing D-MER using logistic regression and performed feature selection with the Akaike Information Criterion (AIC).

The results demonstrated the following findings:

• A high co-incidence of D-MER with both postpartum depression and baby blues in sample of 1469 lactating parents.
• Participants who had either postpartum depression or baby blues had more than twice probability to report D-MER as those who did not.
• Elevated risk was also noted in individuals with pre-pregnancy mental health disorders, higher educational attainment, and an immigration background.
• D-MER was more frequent among those supplementing breastfeeding with formula, suggestive that D-MER during breastfeeding led to alternative feeding choices in these families.
• Likelihood of D-MER was not affected by factors such as marital status, household income, maternal age at first child's birth, BMI, history of medical illness, mode of birth, infant's sex, pregnancy planning, assisted reproductive technology, pregnancy or birth complications, medication use during pregnancy, and hospitalization. 
• Additionally, partner parental leave had no significant effect on D-MER development.

To conclude, healthcare professionals should be particularly vigilant for D-MER in birthing parents with a history of psychiatric disease or those experiencing postpartum depression or baby blues. The discovery that a migration background increases the risk of D-MER is novel and can help clinicians recognize a vulnerable group at higher risk.

Source: Zychlinsky SA, Cappenberg R, Liolios I, GARCIA GJ, HAPPLE C. Risk Factors for Dysphoric Milk Ejection Reflex, American Journal of Obstetrics and Gynecology. 2024. doi: https://doi.org/10.1016/j.ajog.2024.09.102.