Prenatal Stress and Mixed-Handedness

Abstract

Atypical lateralization, as indicated by mixedhandedness, has been related to diverse psychopathologies. Maternal prenatal stress has recently been associated with mixed-handedness in the offspring. In the present study, this relationship was investigated further in a prospective, methodologically comprehensive manner. Stress levels were determined three times during pregnancy by means of questionnaires and measurements of cortisol levels. The handedness of 110 6-y-old children (48 boys) was determined by independent observers. Mixed handedness was defined as using the opposite hand for one or more of the tested activities. Logistic regression analysis showed that more maternal daily hassles in late pregnancy and maternal mixed-handedness increased the chance of mixed-handedness in the offspring. In contrast, more pregnancyrelated fear in late pregnancy and a longer duration of gestation were associated with a smaller chance of being mixed-handed. Prenatal stress measured during the first two periods of pregnancy or determined by cortisol was not related to mixed-handedness in the offspring. In conclusion, reported and physiologic measures of prenatal stress in a moderately stressed pregnant population were only partly related to offspring mixed-handedness. A ccording to the fetal programming hypothesis, the environment in utero can alter the development of the fetus during particular sensitive periods, with a permanent effect on the set point of physiologic systems and the phenotype in later years (1).Maternal prenatal stress has been shown to affect postnatal physical, behavioral, emotional, temperamental, and physiologic outcome of the offspring (2). In animals, maternal prenatal stress has also been linked with atypical laterality in the offspring (3-5). In humans, reduced brain asymmetry and less right-handedness have been proposed as indicators of disturbances in normal brain development and to be related to psychopathology (6). Atypical lateralization, as indicated by mixed-handedness, has been associated with autism (7), dyslexia (8), attention-deficit/hyperactivity disorder (9), and schizophrenia (10). Two recent studies investigated the possible association between maternal prenatal distress (11) and anxiety (12) and offspring mixed-handedness. Obel and colleagues (11) reported that the 3-y-old children of mothers who had experienced more distress and stressful life events during the third trimester of pregnancy had a three-to fourfold higher prevalence of mixed-handedness. Glover et al. (12) reported a significant association between prenatal anxiety measured at 18 wk of pregnancy and mixed-handedness of the 42-mo-old offspring. Furthermore, the authors found a positive relationship between maternal mixed-handedness and offspring mixed-handedness.The two studies measured handedness through parental reports, and although both found maternal prenatal stress to be associated with mixed-handedness, their results differed with respect to the period in pregnancy in which stress exerted this effec...

Handedness and Time to Pregnancy

“…Prenatal stress has been studied as a potential cause of mixed-handedness 30,33,34. In line with these reports, we found an association of lower fecundity with mixed-handedness but not left-handedness.…”

A large-scale population study of early life factors influencing left-handedness

“…Birthweight is a complex trait, which reflects not only healthy variation but also non-optimal development or pathology. Insofar as lower birthweight was associated with left-handedness, this suggests that a minority of left-handers may be linked etiologically to developmental insults, as has been discussed elsewhere 13,57,58 . As regards multiple birth, in a previous study, the effect of being part of a multiple birth was no longer detectable after accounting for the effects of birthweight and APGAR (Appearance, Pulse, Grimace, Activity, Respiration) score; the latter is an indicator of various adverse circumstances that could occur during pregnancy or birth 33 .…”

A large-scale population study of early life factors influencing left-handedness

“…Birthweight is a complex trait which reflects not only healthy variation but also nonoptimal development or pathology. Insofar as lower birthweight was associated with lefthandedness, this suggests that a minority of left-handers may be linked etiologically to developmental insults, as has been discussed elsewhere (Bailey and McKeever, 2004;Gutteling et al, 2007;Nicholls et al, 2012). As regards multiple birth, in a previous study, the effect of twinning was no longer detectable after accounting for the effects of birthweight and APGAR (Appearance, Pulse, Grimace, Activity, Respiration) score (Heikkila et al, 2015).…”