Biomaterial Database

Sex ratio and parental age gap. 1999

P Astolfi, and L A Zonta

Department of Genetics and Microbiology A. Buzzati-Traverso, University of Pavia, Italy.

We tested the hypothesis that a large age difference between parents can shift the sex ratio at birth in favor of males, as Manning et al. (1997) suggested in their analysis of English and Welsh data. Among children born in Lombardy (northern Italy) in 1990 and 1991, we observed an anomalous excess of males born to a particular subsample of parents with a wide age gap (> 15 yr) between them; in the overall sample the father-mother age gap does not significantly contribute to the determination of the child's sex.

UI	MeSH Term	Description	Entries
D007223	Infant	A child between 1 and 23 months of age.	Infants
D007231	Infant, Newborn	An infant during the first 28 days after birth.	Neonate,Newborns,Infants, Newborn,Neonates,Newborn,Newborn Infant,Newborn Infants
D007558	Italy	A country in southern Europe, a peninsula extending into the central Mediterranean Sea, northeast of Tunisia. The capital is Rome.	Sardinia
D008297	Male		Males
D008423	Maternal Age	The age of the mother in PREGNANCY.	Age, Maternal,Ages, Maternal,Maternal Ages
D010290	Parents	Persons functioning as natural, adoptive, or substitute parents. The heading includes the concept of parenthood as well as preparation for becoming a parent.	Step-Parents,Parental Age,Parenthood Status,Stepparent,Age, Parental,Ages, Parental,Parent,Parental Ages,Status, Parenthood,Step Parents,Step-Parent,Stepparents
D012042	Registries	The systems and processes involved in the establishment, support, management, and operation of registers, e.g., disease registers.	Parish Registers,Population Register,Parish Register,Population Registers,Register, Parish,Register, Population,Registers, Parish,Registers, Population,Registry
D002648	Child	A person 6 to 12 years of age. An individual 2 to 5 years old is CHILD, PRESCHOOL.	Children
D002675	Child, Preschool	A child between the ages of 2 and 5.	Children, Preschool,Preschool Child,Preschool Children
D005260	Female		Females