Commentary by: Erin Psota BSc., ND

33087532_mlReference: Beijers R, Jansen J, Riksen-Walraven M, de Weerth C. Maternal prenatal anxiety and stress predict infant illnesses and health complaints. Pediatrics. 2010 Aug;126(2):e401-9.

Design: Prospective cohort study.

Participants: 174 mothers with normal pregnancies and term deliveries in the Netherlands filled out questionnaires during their third trimester to quantify stress and anxiety, and provided saliva samples to assess cortisol levels. Subjects were then interviewed on a monthly basis for the infants’ first year in order to determine the frequency of illness and antibiotic use.

Key Findings: Adjustments were made for confounding factors including, but not limited to, maternal smoking and alcohol use, duration of breast feeding and day-care attendance. The results suggest that maternal stress and anxiety are positive predictors of infant illness and antibiotic use in the first year of life. In particular, the findings show an association between increased maternal stress and anxiety and respiratory, skin and general illnesses and antibiotic use, but not digestive illness. There was also a correlation between higher evening cortisol levels or flattened diurnal cortisol rhythms and increased incidence of infant illnesses.

Practice Implications:
A number of studies have previously established that maternal stress has a negative impact on infant temperament and cognitive development; however this is the first study to explore the effect of prenatal maternal stress on the incidence of infant illness.1,2,3 Evidence from both this and previous studies suggests that it is during the third trimester that the effects of elevated cortisol and maternal stress and anxiety are most influential on post-natal outcomes.4 In fact, it was reported that women exposed to natural disasters (such as hurricanes Andrew and Katrina in the U.S.) during second and third trimesters had an increased risk of fetal distress as compared to those exposed during the first trimester.5,6

It is known that stress can activate beta-adrenergic receptors, which may influence different aspects of cognitive function.7 A 2008 study by Connors et al. suggests that over-stimulation of the beta-adrenergic receptors from stress or drugs such as terbutaline (given to stop preterm labour) are linked to an increased risk for autism.8,9 By establishing a link to increased infant illnesses, this study may also point to a link between the influence of maternal stress on the intrauterine environment and the immune dysfunction in neurodevelopmental disorders such as autism.10

Factors including social and cultural norms, social support and father’s involvement, guidance and support from health-care providers, education and work environment contribute to a woman’s decision to breastfeed, and it seems reasonable that these factors would also influence maternal stress and anxiety as well.11,12,13 While the investigators did adjust for breastfeeding, it should still be considered that mothers who report higher levels of prenatal stress and anxiety may also be those less likely to breastfeed. The positive impact of breastfeeding on the developing immune system is very well established and its protective effects should not be discounted, if not for reducing frequency, but for potentially reducing severity of illness.14 Breastfeeding should continue to be encouraged, particularly in mothers with higher levels of stress and anxiety.

This study reinforces the importance of addressing stress and anxiety in pregnant patients. Both the self-assessment questionnaires and cortisol levels were shown to be predictive of infant illness and antibiotic use, thus it is certainly worthwhile to consider both parameters as tools to monitor this population in practice, potentially saving time during the interview to assess the mother’s stress level and support resources. Early recognition and intervention on the part of the practitioner may very well serve to reduce maternal stress and anxiety thereby reducing infant illness and antibiotic use.

Further investigation is certainly warranted to both confirm the findings of this particular study, as well as to determine the therapeutic effects of how decreasing maternal stress and anxiety in the third trimester can impact infant health.




1 Davis EP, Glynn LM, Schetter CD, Hobel C, Chicz-Demet A, Sandman CA. Prenatal exposure to maternal depression and cortisol influences infant temperament. J Am Acad Child Adolesc Psychiatry. 2007 Jun;46(6):737-46.

2 Martini J, Knappe S, Beesdo-Baum K, Lieb R, Wittchen HU. Anxiety disorders before birth and self-perceived distress during pregnancy: associations with maternal depression and obstetric, neonatal and early childhood outcomes. Early Hum Dev. 2010 May;86(5):305-10.

3 Buitelaar JK, Huizink AC, Mulder EJ, de Medina PG, Visser GH. Prenatal stress and cognitive development and temperament in infants. Neurobiol Aging. 2003 May-Jun;24 Suppl 1:S53-60; discussion S67-8.

4 de Weerth C, van Hees Y, Buitelaar JK. Prenatal maternal cortisol levels and infant behavior during the first 5 months. Early Hum Dev. 2003 Nov;74(2):139-51.

5 Zahran S, Snodgrass JG, Peek L, Weiler S. Maternal hurrican exposure and fetal distress risk. Risk Anal. 2010 Oct;30(10):1590-601.

6 Tees MT, Harville EW, Xiong X, Buekens P, Pridjian G, Elkind-Hirsch K. Hurricane Katrina-related maternal stress, maternal mental health, and early infant temperament. Matern Child Health J. 2010 Jul;14(4):511-8.

7 Yu NN, Wang XX, Yu JT, Wang ND, Lu RC, Miao D, Tian Y, Tan L. Blocking beta2-adrenergic receptor attenuates acute stress-induced amyloid beta peptides production. Brain Res. 2010 Mar 4;1317:305-10.

8 Connors SL, Levitt P, Matthews SG, Slotkin TA, Johnston MV, Kinney HC, Johnson WG, Dailey RM, Zimmerman AW. Fetal mechanisms in neurodevelopmental disorders.  Pediatr Neurol. 2008 Mar;38(3):163-76.

9 Zerrate MC, Pletnikov M, Connors SL, Vargas DL, Seidler FJ, Zimmerman AW, Slotkin TA, Pardo CA. Neuroinflammation and behavioral abnormalities after neonatal terbutaline treatment in rats: implications for autism. J Pharmacol Exp Ther. 2007 Jul;322(1):16-22.

10 Bent S, Hendren RL. Improving the prediction of response to therapy in autism.

Neurotherapeutics. 2010 Jul;7(3):232-40.

11 Lee HJ, Rubio MR, Elo IT, McCollum KF, Chung EK, Culhane JF. Factors associated with intention to breastfeed among low-income, inner-city pregnant women.

Matern Child Health J. 2005 Sep;9(3):253-61.

12 Lee HJ, Elo IT, McCollum KF, Culhane JF. Racial/Ethnic Differences in Breastfeeding Initiation and Duration Among Low-income, Inner-city Mothers.

Soc Sci Q. 2009 Dec 1;90(5):1251-1271.

13 Racial and Ethnic Differences in Breastfeeding Initiation and Duration, by State. National Immunization Survey, United States, 2004—2008. Atlanta, GA. Morbidity and Mortality Weekly Report, Centers for Disease Control and Prevention. March 26, 2010: 59(11);327-334.

14 Duijts L, Jaddoe VW, Hofman A, Moll HA. Prolonged and exclusive breastfeeding reduces the risk of infectious diseases in infancy. Pediatrics. 2010 Jul;126(1):e18-25.

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