Mature maternity: long term associations in first children born to older mothers in 1970 in the UK

Abstract

Study objectives: To identify the physical, behavioural, medical, and educational outcomes in first children born to women aged 30 or more compared with those born to younger women.

Design: Longitudinal cohort study design employing logistic regression analysis of data obtained from the British births survey of 1970 and the child health and education study follow ups to this cohort at ages 5 and 10.

Setting: One week birth cohort covering the whole of the United Kingdom.

Participants: The carers of 4315 first children born to women during the week of April 5th-11th 1970 inclusive in the whole of the United Kingdom except Northern Ireland, and followed up at both 5 and 10 years of age. In addition, information was obtained from health visitors, the child's teacher at 10, and the medical officer who completed an examination. At 10 the child also completed a questionnaire.

Measurements: Data were obtained from questionnaires administered to the carers of the child at each time point, from their teacher at age 10, and from the results of a medical examination at age 10. Educational tests were also conducted at this age.

Main results: Having adjusted for the effects of confounding factors, late primiparity was significantly associated with a number of events in labour and delivery involving obstetric interventions ranging from induction to operative deliveries and general anaesthesia. At 5 years of age, controlling additionally for family size at that time, associations were found between late primiparity and fewer adverse measures of behaviour in the child. Both the child's head circumference and the score on a picture based vocabulary test at this age were slightly greater in the index group. At 10 years of age, adjusting for background factors and present family size, late primiparity was associated with few outcome measures. Children born to older mothers, however, scored slightly higher on a broad range of educational tests administered at school.

Conclusions: No clearly demonstrable adverse outcomes could be linked to later primiparity in the 1970 child health and education study national cohort study. Modest behavioural and educational advantages were detected in the group with older first-time mothers. A woman's later primiparity may be associated with their child having a slightly larger head circumference compared with whole of the rest of the study cohort.