Prenatal attachment: using measurement invariance to test the validity of comparisons across eight culturally diverse countries.

Studies in high-income countries (HICs) have shown that variability in maternal-fetal attachment (MFA) predict important maternal health and child outcomes. However, the validity of MFA ratings in low- and middle-income countries (LMICs) remains unknown. Addressing this gap, we assessed measurement invariance to test the conceptual equivalence of the Prenatal Attachment Inventory (PAI: Muller, 1993) across eight LMICs. Our aim was to determine whether the PAI yields similar information from pregnant women across different cultural contexts. We administered the 18-item PAI to 1181 mothers in the third trimester (Mean age = 28.27 years old, SD = 5.81 years, range = 18-48 years) expecting their first infant (n = 359) or a later-born infant (n = 820) as part of a prospective birth cohort study involving eight middle-income countries: Ghana, Jamaica, Pakistan, Philippines, Romania, South Africa, Sri Lanka and Vietnam. We used Multiple Group Confirmatory Factor Analyses to assess across-site measurement invariance. A single latent factor with partial measurement invariance was found across all sites except Pakistan. Group comparisons showed that mean levels of MFA were lowest for expectant mothers in Vietnam and highest for expectant mothers in Sri Lanka. MFA was higher in first-time mothers than in mothers expecting a later-born child. The PAI yields similar information about MFA across culturally distinct middle-income countries. These findings strengthen confidence in the use of the tool across different settings; future studies should explore the use of the PAI as a screen for maternal behaviour that place children at risk.