The importance of socioeconomic factors on antenatal identification of small for gestational age pregnancies: Exploring health inequalities in the antenatal care in Sweden.

INTRODUCTION: Unidentified small for gestational age (SGA) pregnancies have an increased risk for stillbirth. The risk of stillbirth is increased in women born abroad or with low socioeconomic status (SES). The aim of this study was to evaluate potential inequalities in antenatal screening and identification of SGA by examining whether a foreign background or indicators of low SES were associated with unidentified SGA. MATERIAL AND METHODS: This was a register-based cohort study of all pregnancies delivered in Stockholm in the year 2014 and 2017, including 5487 SGA pregnancies. Data from maternal medical records were linked to nationwide Swedish registers. Exposures were educational level, family income level, recent immigration, social security benefits, civil status, Swedish/foreign background, municipal affiliation, and country of birth. Outcome was unidentified SGA, defined as born SGA with no or normal growth scans performed at or after week 24 + 0 of pregnancy. We used unadjusted and adjusted logistic regression analyses to assess the associations between socioeconomic factors and unidentified SGA. Additionally, an intersectional regression analysis was performed to explore predefined combinations of the exposure factors. RESULTS: Neither educational level, family income level, Swedish/foreign background, or any combination of these factors, nor recent immigration or civil status was associated with unidentified SGA in the adjusted model. Women receiving social security benefits had decreased odds of unidentified SGA, adjusted odds ratio 0.73, 95% confidence interval 0.55-0.97. CONCLUSIONS: Foreign background or indicators of low SES were not positively associated with unidentified SGA. These findings suggest that antenatal screening and identification of SGA are provided on equal terms.