We evaluated whether the maternal marital status and father acknowledgement (proxy for paternal presence) affect birth weight, and if so, whether the maternal educational attainment modifies this effect. The growing tendency of alternative forms of family structure affects maternal well-being and pregnancy outcome. However, it is not known whether poorer birth outcomes of out-of-wedlock childbearing can be overcome or compensated by maternal education. Using birth registry data, we assessed the impact of maternal civil status and child recognition by the father on birth-weight-for-gestational age (BWGA) z-scores, with respect to maternal education, among Polish mothers (N = 53,528). After standardization, the effect of being unmarried with father acknowledgement (UM-F) vs. married with father acknowledgement (M-F) reduced the BWGA z-score of 0.05 (p < 0.001), irrespective of educational attainment (p for interaction = 0.79). However, education differentiated the effect of father acknowledgement across unmarried mothers. BWGA z-scores were significantly lower among the low-educated unmarried group without father acknowledgment (UM-NF) as compared to UM-F (equaled -0.11, p = 0.01). The same effect among the higher-educated group was non-significant (p = 0.72). Higher maternal education can compensate for the negative effect of a lack of father acknowledgement, but it does not help to overcome the effect of out-of-wedlock stress exposure.
Keywords: birth outcomes; birth weight; educational status; family structure; father absence; marital status; non-traditionally married mothers; paternal acknowledgement; psychological stress; social support.