Open Access Research article

Temporal changes in key maternal and fetal factors affecting birth outcomes: A 32-year population-based study in an industrial city

Svetlana V Glinianaia1*, Judith Rankin1, Tanja Pless-Mulloli1, Mark S Pearce12, Martin Charlton3 and Louise Parker4

Author Affiliations

1 Institute of Health and Society, Newcastle University, William Leech Building, The Medical School, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK

2 School of Clinical Medical Sciences (Child Health), Newcastle University, Sir James Spence Institute, Royal Victoria Infirmary, Newcastle upon Tyne, NE1 4LP, UK

3 National Centre for Geocomputation, John Hume Building, National University of Ireland Maynooth, Maynooth, County Kildare, Ireland

4 Departments of Medicine and Paediatrics, Dalhouise University, Faculty of Computer Science, 6050 University Avenue, Halifax, Nova Scotia, B3H 1W5, Canada

For all author emails, please log on.

BMC Pregnancy and Childbirth 2008, 8:39  doi:10.1186/1471-2393-8-39

Published: 19 August 2008

Abstract

Background

The link between maternal factors and birth outcomes is well established. Substantial changes in society and medical care over time have influenced women's reproductive choices and health, subsequently affecting birth outcomes. The objective of this study was to describe temporal changes in key maternal and fetal factors affecting birth outcomes in Newcastle upon Tyne over three decades, 1961–1992.

Methods

For these descriptive analyses we used data from a population-based birth record database constructed for the historical cohort Particulate Matter and Perinatal Events Research (PAMPER) study. The PAMPER database was created using details from paper-based hospital delivery and neonatal records for all births during 1961–1992 to mothers resident in Newcastle (out of a total of 109,086 singleton births, 97,809 hospital births with relevant information). In addition to hospital records, we used other sources for data collection on births not included in the delivery and neonatal records, for death and stillbirth registrations and for validation.

Results

The average family size decreased mainly due to a decline in the proportion of families with 3 or more children. The distribution of mean maternal ages in all and in primiparous women was lowest in the mid 1970s, corresponding to a peak in the proportion of teenage mothers. The proportion of older mothers declined until the late 1970s (from 16.5% to 3.4%) followed by a steady increase. Mean birthweight in all and term babies gradually increased from the mid 1970s. The increase in the percentage of preterm birth paralleled a two-fold increase in the percentage of caesarean section among preterm births during the last two decades. The gap between the most affluent and the most deprived groups of the population widened over the three decades.

Conclusion

Key maternal and fetal factors affecting birth outcomes, such as maternal age, parity, socioeconomic status, birthweight and gestational age, changed substantially during the 32-year period, from 1961 to 1992. The availability of accurate gestational age is extremely important for correct interpretation of trends in birthweight.