The effects of 'does not apply' on measurement of temperament with the Infant Behavior Questionnaire-Revised: A cautionary tale for very young infants

Background The Infant Behavior Questionnaire—Revised (IBQ-R) is a widely used parent report measure of infant temperament. Items marked ‘does not apply’ (NA) are treated as missing data when calculating scale scores, but the effect of this practice on assessment of infant temperament has not been reported. Aims To determine the effect of NA responses on assessment of infant temperament and to evaluate the remedy offered by several missing data strategies. Study design A prospective, community-based longitudinal cohort study.Subjects401 infants who were born > 37 weeks of gestation. Outcome measures Mothers completed the short form of the IBQ-R when infants were 3-months and 6-months of age. Results The rate of NA responses at the 3-month assessment was three times as high (22%) as the rate at six months (7%). Internal consistency was appreciably reduced and scale means were inflated in the presence of NA responses, especially at 3-months. The total number of NA items endorsed by individual parents was associated with infant age and parity. None of the missing data strategies completely eliminated problems related to NA responses but the Expectation Maximization algorithm greatly reduced these problems. Conclusions The findings suggest that researchers should exercise caution when interpreting results obtained from infants at 3 months of age. Careful selection of scales, selecting a full length version of the IBQ-R, and use of a modern missing data technique may help to maintain the quality of data obtained from very young infants

Advancing gestation does not attenuate biobehavioural coherence between psychological distress and cortisol

Background Despite little evidence to suggest that HPA axis responses to psychological provocation are attenuated during pregnancy, it is widely held that dampening of the HPA axis response to psychological distress serves a protective function for the mother and fetus. The current study was designed to assess changes in biobehavioral coherence between psychological distress and cortisol over the course of pregnancy. Methods Ambulatory assessment of ecologically relevant psychological distress and salivary cortisol were repeated in all three trimesters for 82 pregnant women. Samples were collected 5 times per day over the course of 2 days in each trimester. Results Psychological distress and cortisol were positively associated, β = .024, p < .01, indicating that increases in psychological distress were associated with increases in cortisol. Gestational age did not moderate this association, β = .0009, p = .13, suggesting that negative psychological experiences remain potent stimuli for the HPA axis during pregnancy. Conclusion Biobehavioral coherence between ecologically relevant experiences of psychological distress and cortisol is not attenuated with advancing gestation. Highlights ► We assess changes in the association between psychological distress and cortisol over the course of pregnancy. ► Psychological distress was associated with cortisol throughout pregnancy. ► Psychological experiences remain potent stimuli for the HPA axis during pregnancy. ► Advancing gestation does not protect the mother or fetus from the psychobiological effects of distress. Keywords: Psychological distress, Salivary cortisol, Pregnancy, Stress response, HPA axis, Biobehavioural coherenc

The Alberta Pregnancy Outcomes and Nutrition (APrON) cohort study:Rationale and methods

The Alberta Pregnancy Outcomes and Nutrition (APrON) study is an ongoing prospective cohort study that recruits pregnant women early in pregnancy and, as of 2012, is following up their infants to 3 years of age. It has currently enrolled approximately 5000 Canadians (2000 pregnant women, their offspring and many of their partners). The primary aims of the APrON study were to determine the relationships between maternal nutrient intake and status, before, during and after gestation, and (1) maternal mood; (2) birth and obstetric outcomes; and (3) infant neurodevelopment. We have collected comprehensive maternal nutrition, anthropometric, biological and mental health data at multiple points in the pregnancy and the post-partum period, as well as obstetrical, birth, health and neurodevelopmental outcomes of these pregnancies. The study continues to follow the infants through to 36 months of age. The current report describes the study design and methods, and findings of some pilot work. The APrON study is a significant resource with opportunities for collaboration

The PedBE clock accurately estimates DNA methylation age in pediatric buccal cells

Stress and Psychopatholog