Answers are grounded in this paper and cite their sources.
Parental ages and birth order were analysed in 16 sporadic cases of inv dup (15) using the method of Smith. A significant maternal age effect was apparent (dm = 5.989, SE 1.86; df = 2.02, SE 2.496; db = 0.138, SE 0.46).
No takes yet. Share an insight, caveat, or question.
Connor et al. (1984) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: