Vertical transmission
Passage of a disease-causing agent (a pathogen) vertically from mother directly to baby during the perinatal period, the period immediately before and after birth. The perinatal period is defined in diverse ways. Depending on the definition, it starts at the 20th to 28th week of gestation and ends 1 to 4 weeks after birth. A vertically transmitted pathogen might, for example, be HIV (the human immunodeficiency virus). Transmission might occur across the placenta or in the breast milk. Also called perinatal transmission.
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transmission from one generation to another. The term is restricted by some to genetic transmission and extended by others to include also transmission of infection from one generation to the next, as by maternal milk or through the placenta. Cf. horizontal t.
Medical dictionary.
2011.