STUDY QUESTION: Is anxiety focused on the pregnancy outcome, known to be particularly salient in women conceiving through assisted reproductive technology (ART), related to difficult infant temperament?SUMMARY ANSWERWhile trait anxiety predicts infant temperament, pregnancy-focused anxiety is not associated with more difficult infant temperament.WHAT IS KNOWN ALREADYA large body of research has provided convincing evidence that fetal exposure to maternal anxiety and stress in pregnancy has adverse consequences for child neurodevelopmental, behavioural and cognitive development, and that pregnancy-specific anxiety (concerns related to the pregnancy outcome and birth) may be of particular significance. Women conceiving through ART are of particular interest in this regard. Research over more than 20 years has consistently demonstrated that while they do not differ from spontaneously conceiving (SC) women with respect to general (state and trait) anxiety, they typically report higher pregnancy-specific anxiety. While research suggests normal behavioural and developmental outcomes for children conceived through ART, there is some evidence of more unsettled infant behaviour during the first post-natal year.STUDY DESIGN, SIZE, DURATIONThe longitudinal cohort design followed 562 nulliparous women over a 7-month period, during the third trimester of pregnancy and at 4 months after birth.PARTICIPANTS/MATERIALS, SETTING, METHODSApproximately equal numbers of nulliparous women conceiving through ART (n = 250) and spontaneously (SC: n = 262) were recruited through ART clinics and nearby hospitals in Melbourne and Sydney, Australia. Participants completed three anxiety measures (state, trait, pregnancy specific) at time 1 in the third trimester of pregnancy and a measure of infant temperament at time 2, 4 months after birth. At time 1, relevant socio-demographic, pregnancy (maternal age, smoking, alcohol, medications, medical complications) information was recorded and at time 2, information regarding childbirth (gestation, infant birthweight, mode of delivery) and post-natal (concurrent mood) variables was recorded and controlled for in analyses. MAIN RESULTS AND THE ROLE OF CHANCE: In the third trimester of pregnancy, women conceiving through ART reported lower state and trait anxiety, but higher pregnancy-focused anxiety than their SC counterparts (all Ps < 0.05). Hierarchical regression analyses including mode of conception, all anxiety variables and relevant covariates indicated that while trait anxiety in pregnancy predicted more difficult infant temperament (P < 0.001), pregnancy specific and state anxiety did not. Mode of conception predicted infant temperament; with ART women reporting less difficult infant temperament (P < 0.001) than their SC counterparts. LIMITATIONS, REASONS FOR CAUTION: The major limitations in the study are the reliance on a self-report measure of infant temperament and the fact that the study did not assess quality of caregiving which may moderate the effect of pregnancy anxiety on infant temperament. WIDER IMPLICATIONS OF THE FINDINGS: This study is the first to our knowledge to prospectively examine the impact of gestational stress (pregnancy anxiety) on infant temperament in women conceiving through ART. Findings confirm existing research indicating that trait anxiety in pregnancy is associated with difficult infant temperament and suggest that pregnancy-specific anxiety (measured in the third trimester) is not implicated. These findings are reassuring for women conceiving through ART whose pregnancies may be characterized by particularly intense concerns about the wellbeing of a long sought after baby. STUDY FUNDING/COMPETING INTEREST(S): The study was funded by a grant from the Australian Research Council (ARC) and in kind and financial contributions from IVF Australia and Melbourne.TRIAL REGISTRATION NUMBERN/A.