PARIS – Maternal somatic anxiety during pregnancy and early childhood is associated in dose-response fashion with increased hyperactivity symptoms in mothers’ teenage children, according to an update from the landmark Avon Longitudinal Study of Parents and Offspring.
Perhaps the most intriguing finding in the new analysis was that the dose-response effect did not apply to the offspring of mothers in the highest quintile of somatic anxiety as measured during pregnancy and early childhood.
“It’s possible that a ceiling effect exists for those children that are exposed to continuous high levels of anxiety from pregnancy up to 5 years old,” Blanca Bolea-Alamanac, PhD, said at the annual congress of the European College of Neuropsychopharmacology.
Dr. Bolea-Alamanac of the department of psychiatry at the University of Toronto offered a couple possible explanations for this apparent ceiling effect. One is that children continuously exposed to high levels of maternal stress hormones in utero and through breast feeding become desensitized to the effects of those hormones in ways that affect their future behavior.
Another possibility is that children exposed to very high levels of anxiety in early life later develop internalizing-type symptoms rather than externalizing hyperactivity-type symptoms, she continued.
The Avon Longitudinal Study of Parents and Children is a birth cohort study conducted in Southwest England, where women who were pregnant in 1990 and their 14,062 offspring have been followed prospectively for 26 years.
Dr. Bolea-Alamanac’s analysis included the 8,725 women with maternal anxiety assessments obtained at 18 and 32 weeks of pregnancy, as well as at 8 weeks, 8 months, 2.67 years, and 5 years post partum. Maternal anxiety was measured using the Crown-Crisp Experiential Index, which provided a specific indicator of somatic anxiety via responses to questions including, “Are you troubled by dizziness or shortness of breath?” “Do you experience a tingling or prickling sensation in your body, arms, or legs?” “Have you felt that you may faint, feel sick, or have indigestion?” and “Do you experience extra sweating?” The response options to each question were “never,” “sometimes,” “often,” or “very often.”
All women understandably experienced increased anxiety during pregnancy, peaking in the weeks shortly prior to delivery. But by examining the totality of data obtained at two time points in pregnancy and four points post pregnancy, the psychiatrist was able to construct a model with five distinct quintiles of maternal anxiety.
Hyperactivity symptoms were assessed in 3,417 of their offspring using the Strengths and Difficulties Questionnaire hyperactivity subscale.
Class 1, the reference class, was comprised of women with low anxiety during pregnancy and after delivery. In a logistic regression analysis adjusted for maternal age, alcohol intake, and education, life events during pregnancy, socioeconomic status, and the child’s sex, the women in class 2 were at 1.44-fold increased risk of having a hyperactive teenager. Those who were more anxious, in class 3, were at 1.87-fold increased risk, and those in class 4 were at 2.5-fold greater risk than those in class 1. All those increased risks were statistically significant.
In contrast, women in class 5 – those who scored highest for somatic anxiety both in pregnancy and during the next 5 years – had only a nonsignificant trend toward an increased risk of having a hyperactive teenager.
The association between prenatal and postnatal maternal somatic anxiety and hyperactivity symptoms in their children seen in the Avon study is consistent with Barker’s theory, according to Dr. Bolea-Alamanac. Barker’s theory, developed by the prominent late British epidemiologist David Barker, MD, PhD, holds that intrauterine influences interact with the environment at birth to produce specific disease risks for the child. Dr. Barker’s theory has gained considerable traction over the years, as evidenced by the creation of the multidisciplinary International Society for Developmental Origins of Health and Disease.
Dr. Bolea-Alamanac reported having no relevant financial conflicts of interest.