title: Birth records from Swiss married couples analyzed over the past 35 years reveal an aging of first-time mothers by 5.1 years while the interpregnancy interval has shortened.
abstract: Although the general trend for delaying childbearing is generally viewed as causing infertility, its consequences on the interpregnancy interval have been unknown. A study of birth records for Swiss married women from 1969 to 2006 revealed that the woman's age at first birth has increased from 25.0 to 30.1 years, whereas calculated theoretical interpregnancy intervals after the first and second child decreased from 23.2 to 13 and from 22.4 to 7.9 months, respectively.
authors.affiliation: Department of Obstetrics and Gynecology, University Hospital of Lausanne, Maternity, CHUV, Lausanne, Switzerland.
authors.forename: Urs
authors.initials: U
authors.lastname: Kalberer
authors.forename: David
authors.initials: D
authors.lastname: Baud
authors.forename: Arnaud
authors.initials: A
authors.lastname: Fontanet
authors.forename: Patrick
authors.initials: P
authors.lastname: Hohlfeld
authors.forename: Dominique
authors.initials: D
authors.lastname: de Ziegler
mesh_terms: D000328:Adult; D000375:Aging; D001719:Birth Certificates; D001721:Birth Intervals / Q000706:statistics & numerical data*; D005260:Female; D005298:Fertility; D006801:Humans; D008393:Marriage / Q000706:statistics & numerical data*; D008423:Maternal Age; D010298:Parity; D011247:Pregnancy; D013557:Switzerland / Q000453:epidemiology