Written by Chrystal Moulton, Staff Writer. In a study with 50 pregnant women researchers found the cause of maternity blues may be due to low tryptophan levels.
For first time mothers, pregnancy is a period of great expectations. The stress of caring for oneself and preparing for new life is at times overwhelming. Once the new child is brought into the world safely, one can breathe a sigh of relief. However, for 80% of women there is one common hurdle to jump—a transient period of sadness after delivery, duly noted as postpartum blues or the baby blues.(1) This non-pathological mild depressive state usually occurs within the first week post-delivery and could persist from a few days to a couple of weeks.(1) Symptoms of the baby blues include: weepiness, anxiousness, irritability, mood swings, difficulty sleeping, and poor concentration. (1,2) Researchers are not exactly clear what mechanisms in the body are responsible for the onset of minor depression in women postpartum. However, the prevalence of the baby blues and its common side effects in mothers demonstrate the occurrence of a clear biological change after delivery.
In a correlation study (3), researchers wanted to find a link between the availability of tryptophan and the intensity of the baby blues. Researchers recruited pregnant women from the Central University Hospital system in Bordeaux who had no complications during pregnancy or any expected problems at the time of delivery. Fifty pregnant women were included in the study. Information on history of mood disorders, age, weeks of pregnancy, and marital status was also collected. Blood samples were taken just before delivery (D0) and 3 days after delivery (D3) to assess levels of tryptophan along with other amino acids that may compete for uptake into the brain. Mood assessment was also done on day 3 (D3) after delivery to determine intensity of baby blues.
Results showed that although there was a mild increase in tryptophan (19%) postpartum, other amino acids known to compete with tryptophan significantly increased as well. Notably, isoleucine increased 77%, leucine 55%, and tyrosine 52% from day 0 to-day 3 (p<0.0001). Given the values for amino acids in non-pregnant adults, researchers attributed the rise in these competitive amino acids to the body changing from the pregnant state back to normal levels. This change, however, decreases the availability of tryptophan. Researchers calculated from just before delivery to post-delivery, the rise in competitive amino acids is related to a 15% decrease in brain tryptophan availability (p<0.01). When researchers analyzed the relationship between mood and tryptophan availability, they found that brain tryptophan availability was negatively correlated with the intensity of the baby blues (r= -0.283, p<0.05). In other words, high scores on the mood assessment test were correlated to a decrease in tryptophan availability.
In all, according to the study, the short period of the baby blues that seems to affect most women postpartum may be attributed to a sudden increase in the concentration of other amino acids, which compete with tryptophan. This competition decreases the availability of tryptophan which in turn, correlates to the occurrence of the postpartum blues. More studies will be needed to confirm the findings. What should be noted is the clear difference between postpartum blues and postpartum depression. Postpartum depression is more severe and could last for years if left unnoticed. Researchers in this study looked for amino acid changes linked to postpartum blues, which is an immediate mild transient depressive state. Much research continues on postpartum depression, however no clear cause has been found.
Source: Henry, C., et al. “Decreased brain tryptophan availability as a partial determinant of post-partum blues.” Psychoneuroendocrinology 31.3 (2006): 407-413.
Copyright © 2005 Elsevier Ltd. All rights reserved.
Posted January 23, 2014.
Chrystal Moulton BA, PMP, is a 2008 graduate of the University of Illinois at Chicago. She graduated with a bachelor’s in psychology with a focus on premedical studies and is a licensed project manager. She currently resides in Indianapolis, IN.
References:
- Post-partum blues and mild depressive symptomatology at days three and five after delivery: A French cross-sectional study. A-L Sutter, V Leroy, D Dallay, et al. Journal of Affective Disorders, June 1997, 44(1): 1-4.
- Maternity blues reassessed. Kennerley H, Gath D. Psychiatric Developments. 1986 Spring;4(1):1-17.
- Decreased brain tryptophan availability as a partial determinant of post-partum blues. K.M’ Baïlara, C. Henry, J. Lestage, et al. Psychoneuroendocrinology, April 2006, 31(3): 407-413.
