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. 2021 Feb 4;129(2):027002. doi: 10.1289/EHP7331

Figure 1.

Figure 1 is a flow chart having eight steps. Step 1: Live births 1991to 2011 with lowercase italic n equals 1381847 including preterm with lowercase italic n equals 89282 and missing gestational age with lowercase italic n equals 12430. Step 2: Full term with lowercase italic n equals 1280135 including multiple births with lowercase italic n equals 29320 and missing number of births with lowercase italic n equals 18. Step 3: Singletons with lowercase italic n equals 1250797 including less than 8 nitrate measures with lowercase italic n equals 108553 and missing nitrate measures with lowercase italic n equals 31701. Step 4: Greater than or equal to 8 nitrate measures with lowercase italic n equals 1110543 including mother born abroad with lowercase italic n equals 148362 and unknown place of birth with lowercase italic n equals 2023. Step 5: Danish born mothers with lowercase italic n equals 960158 including father born abroad with lowercase italic n equals 54323 and unknown place of birth with lowercase italic n equals 7629. Step 6: Danish born father with lowercase italic n equals 898206 including non-complete covariate(s) with lowercase italic n equals 43082. Step 7: Complete covariates for main models with lowercase italic n equals 855124 including missing birth weight with lowercase italic n equals 2776, missing body length with lowercase italic n equals 7018, and missing head circumference with lowercase italic n equals 266143. Step 8: Birth weight analysis population with lowercase italic n equals 852348, body length analysis population with lowercase italic n equals 848106, and head circumference analysis population with lowercase italic n equals 588981.

Flow diagram of restriction of the cohort to the birth weight, body length at birth, and head circumference at birth analysis populations. Note: Main model covariates included: maternal age, calendar year, sex, gravidity, maternal smoking, maternal education, maternal income, maternal employment status, region, and urbanicity. Head circumference data were available only for births in and after 1997.