Year-end Sale % OFF 
Abstract
BackgroundThe average age at first birth is steadily increasing in developed countries; however, demographic shifts in maternal age at childbearing have not occurred in isolation. While temporal increases in adverse pregnancy outcomes are typically attributed to increases in maternal age, little is known about how maternal health status has changed across maternal age, period of delivery, and birth cohort.MethodsNatality files were used to identify primiparous women delivering liveborn, singleton infants in the USA in 1989, 1994, 1999, 2004, 2009, and 2014 (n = 6,857,185). Age-period-cohort models using the intrinsic estimator adjusted for temporal trends in smoking and gestational weight gain were used to quantify temporal changes in the rates of pre-existing (chronic hypertension, pre-existing diabetes) and pregnancy-associated (pregnancy-associated hypertension, gestational diabetes, eclampsia) diseases. Log-linear models were used to model the impact of temporal changes on preterm birth, small, and large for gestational age (SGA/LGA) births.ResultsSignificant period effects resulted in temporal increases in the rate of chronic hypertension, pregnancy-associated hypertension, and gestational diabetes, and a significant decrease in the rate of eclampsia. These observed period effects were associated with a 10.6% increase in the rate of SGA and a 7.1% decrease in LGA. Had the rate of pre-existing and pregnancy-associated diseases remained static over this time period, the rate of preterm birth would have increased by 5.9%, but instead only increased by 4.4%.ConclusionsIndependent of changes in the incidence of pre-existing and pregnancy-associated diseases as women age, the obstetric population is becoming less healthy over time. This is important, as these changes have a direct negative impact on short-term obstetric outcomes and women’s long-term health.
Highlights
The average age at first birth is steadily increasing in developed countries; demographic shifts in maternal age at childbearing have not occurred in isolation
This study aimed to examine the age, period, and cohort effects in the prevalence of pre-existing disease and the incidence of pregnancy-associated disease in the obstetric population, and to quantify the impact that temporal changes in pre-existing and pregnancy-associated diseases over a 25-year period have had on obstetric outcomes above and beyond the impact of maternal age alone
The rate of chronic hypertension, pregnancyassociated hypertension, and gestational diabetes increased over time for all age groups, while the rate of eclampsia decreased over time for all age groups (Appendix 1)
Summary
The average age at first birth is steadily increasing in developed countries; demographic shifts in maternal age at childbearing have not occurred in isolation. While temporal increases in adverse pregnancy outcomes are typically attributed to increases in maternal age, little is known about how maternal health status has changed across maternal age, period of delivery, and birth cohort. The average age at first birth increased from 24.9 years in 2000 to 26.3 years in 2014 in the USA [1] This rise in the average age at first birth is Metcalfe et al Biology of Sex Differences (2020) 11:19 pregnancy, leading to an increased rate of pregnancy complications [3]. As the average age at first birth steadily increases, the group of primiparous women giving birth at older ages includes more healthy women than ever before [7]. Increased use of assisted reproductive technologies allows less healthy women, in all age groups, to conceive [8]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
