Cumulative incidence of XXXX in a New Zealand birth cohort to age 38 by sex and the relationship with family formation.

@entity1 @entity249
OBJECTIVE: To estimate the cumulative incidence of @entity249 for @entity1 and @entity1 in a population-based sample. DESIGN: Longitudinal study of a birth cohort. SETTING: Research unit. @entity1 (S): A population-based birth cohort of 1,037 @entity1 and @entity1 born in Dunedin, New Zealand, between 1972 and  1973. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Cumulative incidence of @entity249 by age 32 and 38, distribution of causes and service use for @entity249 , live birth subsequent to @entity249 , and live birth by age  38. RESULT(S): The cumulative incidence of @entity249 by age 38 ranged from 14.4% to 21.8% for @entity1 and from 15.2% to 26.0% for @entity1 depending on the @entity249 definition and data used. Infertility, defined as having tried to conceive for 12  months or more or having sought medical help to conceive, was experienced by 21.8% (95% confidence interval [CI], 17.7-26.2) of @entity1 and 26.0% (95% CI, 21.8-30.6) of @entity1 by age 38. For those who experienced @entity249 , 59.8% (95% CI, 48.3-70.4) of @entity1 and 71.8% (95% CI, 62.1-80.3) of @entity1 eventually had a live birth. Successful resolution of @entity249 and entry into parenthood by age 38 were much lower for those who first experienced @entity249 in their mid to late thirties compared with at a younger age. CONCLUSION(S): Comparison of reports from two assessments in this cohort study suggests @entity249 estimates from a single cross-sectional study may underestimate lifetime @entity249 . The lower rate of resolution and entry into parenthood for those first experiencing @entity249 in their mid to late thirties highlights the consequences of postponing parenthood and could result in involuntary childlessness and fewer @entity1 than desired.
