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Birth weight, placental weight and gestation time in relation to natural selection in Thailand
Author(s) -
PROMBOON S.,
MI M. P.,
CHATURACHINDA K.
Publication year - 1983
Publication title -
annals of human genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.537
H-Index - 77
eISSN - 1469-1809
pISSN - 0003-4800
DOI - 10.1111/j.1469-1809.1983.tb00980.x
Subject(s) - gestation , birth weight , obstetrics , medicine , in utero , pregnancy , biology , fetus , genetics
Summary Birth weight, placental weight and gestation time of 26258 single births at Ramathibodi Hospital during 1973–7 were studied in relation to natural selection by fitting quadratic function to natural log of survivors‐to‐nonsurvivors ratios. The survival criterion was 7 days after delivery. The estimated optimal values of birth weight and placental weight were 0.62 and 0.90 standard deviations, respectively, above the corresponding arithmetic means. Selection on birth weight and placental weight was asymmetrical about the optima, being more intense among the lower than the higher values. On the other hand, selection on gestation time seemed most stabilized with the optimum almost coinciding with the mean.