Abstract
Parental genetic relatedness may lead to adverse health and fitness outcomes in the offspring. It is not known whether it affects human delivery timing. Here, we use genotype data from ~20000 parent-offspring trios from the Norwegian Mother, Father and Child Cohort study to optimize runs of homozygosity (ROH) calling by maximising the correlation between parental genetic relatedness and offspring ROHs using different ROH calling parameters. We then estimate the effect of maternal, paternal, and fetal autozygosity and that of autozygosity mapping on the timing of delivery. Varying ROH calling parameters have a strong impact on the coefficient of determination between parental genetic relatedness and offspring ROH, ranging between 0.01-0.72. We observed no effect of maternal, paternal nor fetal autozygosity on spontaneous delivery timing, yet, we identified six maternal and six fetal loci not previously associated with the timing of spontaneous delivery. Moving beyond traditional genome-wide association studies has provided new insights on the genetic determinants and architecture of delivery timing.