Department of Obstetrics and Gynecology, Foothills Medical Centre, University of Calgary, 1403 29 St NW, Calgary, Alberta, T2N 2T9, Canada.
Department of Community Health Sciences, University of Calgary, Calgary, Canada.
Biol Sex Differ. 2020 Apr 19;11(1):19. doi: 10.1186/s13293-020-00293-9.
The 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.
Natality 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.
Significant 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%.
Independent 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.
在发达国家，初育年龄稳步上升；然而，产妇生育年龄的人口结构变化并非孤立发生。虽然通常认为不良妊娠结局的增加与产妇年龄的增加有关，但对于产妇年龄、分娩时期和出生队列的产妇健康状况变化知之甚少。
利用出生率档案，在美国于 1989 年、1994 年、1999 年、2004 年、2009 年和 2014 年，识别出初次分娩活产单胎婴儿的初产妇（n=6857185）。使用内在估计器的年龄-时期-队列模型，调整吸烟和妊娠体重增加的时间趋势，以量化先存（慢性高血压、先存糖尿病）和妊娠相关（妊娠相关高血压、妊娠糖尿病、子痫前期）疾病的发生率的时间变化。对数线性模型用于模拟时间变化对早产、小于胎龄和大于胎龄（SGA/LGA）出生的影响。
显著的时期效应导致慢性高血压、妊娠相关高血压和妊娠糖尿病的发生率增加，子痫前期的发生率降低。这些观察到的时期效应与 SGA 的发生率增加 10.6%和 LGA 的发生率降低 7.1%有关。如果在此期间先存和妊娠相关疾病的发生率保持不变，早产的发生率将增加 5.9%，但实际上仅增加了 4.4%。
随着女性年龄的增长，独立于先存和妊娠相关疾病的发病率变化，产科人群的健康状况在逐渐恶化。这很重要，因为这些变化对短期产科结局和妇女的长期健康有直接的负面影响。
