The use of interventions during childbirth is increasing (WHO, 2018) and, while such interventions can be life-saving, they may have a negative impact on the mother’s experience of birth and her psychological wellbeing post birth. They may also adversely affect the newborn infant’s physiology and behaviour (Taylor, Swift & Glover, 2000; Gitau et al., 2001; Douglas & Hill, 2013). However, little is known about whether the birth and early postnatal experiences influence infant behavioural style (known as temperament) (Thomas & Chess, 1977) beyond the initial postnatal period. Employing an exploratory mixed methods approach, the overarching aim of this thesis was to explore how any potential impacts of birth experience on newborn infant behaviours may occur, and if so, whether they persist beyond the neonatal period; as well, to explore how the mother’s response to her birth experience might mediate such effects. Part One involved a qualitative exploration of the experiences and beliefs of eighteen health professionals and twenty-two mothers in relation to childbirth and early infant behavioural style. Health professionals interviewed in Study One believed that the birth experience could have a direct impact on newborn wellbeing and behaviour as well as influencing it indirectly via the mother’s response to the birth and her subsequent perceptions of and interactions with her baby. In contrast, most of the mothers interviewed in Study Two did not perceive any association between their birth experience and their baby’s early behavioural style. However, a simple content analysis highlighted strong patterns in the data between reported maternal physical and emotional birth experiences and perceived infant temperament during the first year. Part Two (Study Three) involved a detailed online survey of approximately a thousand mothers, employing quantitative methods of analysis. Although physical birth factors contributed to the newborn baby’s response (e.g. alert-content or cry-fuss behaviours), it was subjective and psychological birth factors that predicted ongoing infant behavioural style (0-6 months), for example alert-responsive or unsettled, irritable infant behaviours. Taken together, the data suggest that subjective and psychological factors could be as important as objective physical factors in post-birth mother-infant wellbeing and developing infant temperament. These findings may have important implications for future maternity and perinatal care of mothers and their infants.