calculated litter size measurement number of perinatal live-born offspring deaths to litter size ratio 2014-05-27T16:50:04Z A calculated measurement in which the number of offspring which are born alive but die shortly following birth is divided by the total number of offspring in the litter, and the result presented as a ratio, fraction, quotient or percentage. CMO:0002384 JSmith VT:0005372 clinical_measurement_ontology neonatal death of offspring shortly after birth as percentage of total litter number of neonatal deaths to total litter size ratio percent neonatal deaths percent post-birth perinatal deaths calculated offspring mortality measurement