Understanding of the continuity of fetal with postnatal growth and the heritability of fetal size has been based largely on studies of birth size. Because intrauterine influences may be greater near birth, birth size may be a poor representative of growth earlier in fetal life. This paper presents correlations between ultrasound dimensions measured twice during fetal life between 13 and 36 weeks of gestation and analogous anthropometric variables measured twice postnatally between 6 and 16 months on the same individuals (n=51). Measurements taken during these age intervals should be free of the most intensified intrauterine influences operating near birth. Shared variance between the two periods (about 10-35%) is significant but substantially lower than variance shared between measurements taken within each period (36 to 90%). Correlations between the repeated fetal measurements are lower than those between postnatal dimensions (0.6 versus 0.9). Maternal linear and cranial dimensions have higher associations with postnatal than with fetal measurements, while measures of maternal prepregnancy body fatness are negatively associated with fetal cranial dimensions. Birth weight has similar correlations with fetal and postnatal measurements (between 0.3 and 0.5). However, birth weight explains significant variance for fetal cranial dimensions but not fetal femur length. These findings indicate that significant variance in fetal size is shared with postnatal size. Greater continuity is apparent for linear (femur length and recumbent length) than for cranial dimensions. This suggests that intrauterine influences may have more intense effects on cranial than on linear growth.
Cronk, Christine E.; Kurtz, Alfred B.; and Rosenthal, Elana
"Relationship of Fetal Ultrasound Measurements to Postnatal Anthropometric Variables and Maternal Measurements,"
1, Article 5.
Available at: https://digitalcommons.wayne.edu/humbiol/vol58/iss1/5