Teitler Julien O, Chegwin Valentina, Li Linda, Liu Kayuet, Bearman Peter S, Gorney-Daley Marilyn A, Reichman Nancy E
School of Social Work, Columbia University, New York, New York.
Department of Sociology, University of California, Los Angeles, Los Angeles, California.
AJPM Focus. 2022 Nov 24;2(1):100052. doi: 10.1016/j.focus.2022.100052. eCollection 2023 Mar.
Cesarean section deliveries in the U.S. increased from 5% of births in 1970 to 32% in 2020. Little is known about trends in cesarean sections and inductions in low-risk pregnancies (i.e., those for which interventions would not be medically necessary). This study addresses the following questions: (1) what is the prevalence of elective deliveries at the population level?, (2) how has that changed over time?, and (3) to what extent do the rates of elective deliveries vary across the population?
We first documented long-term trends in cesarean sections in the U.S., California, and New Jersey. We then used linked birth and hospital discharge records and an algorithm based on Joint Commission guidelines to identify low-risk pregnancies and document trends in cesarean sections and inductions in low-risk pregnancies in California and New Jersey over a recent 2-decade period, overall and by maternal characteristics and gestational age.
In low-risk pregnancies in California and New Jersey, rates of cesarean sections and inductions increased sharply from the early 1990s through the mid-2000s, peaked at 33% in California and 41% in New Jersey in 2007, and then declined somewhat, and the proportions of inductions that were followed by cesarean sections increased from fewer than 1 in 5 to about 1 in 4. More education, non-Hispanic White race/ethnicity, U.S.-born status, and non-Medicaid were associated with higher rates of interventions. Trends were similar across all socioeconomic groups, but differences have been narrowing in California. Among early-term (gestational age of 37-38 weeks) births in low-risk pregnancies, the rates of elective deliveries increased substantially in both states until the mid/late-2000s, peaked at about 35% in California and over 40% in New Jersey, and then decreased in both states to about 20%.
Given established health risks of nonmedically necessary cesarean sections, that a nontrivial share of induced deliveries in low-risk pregnancies result in cesarean sections, and that interventions in low-risk pregnancies have not substantially declined since their peak in the mid-2000s, the trends documented in this paper suggest that sustained, even increased, public health attention is needed to address the still-too-high rates of cesarean sections and inductions in the U.S.
美国剖宫产分娩率从1970年占分娩总数的5%上升至2020年的32%。对于低风险妊娠（即那些医学上无需干预的妊娠）中剖宫产和引产的趋势，人们了解甚少。本研究探讨以下问题：（1）在人群层面，择期分娩的发生率是多少？（2）随时间推移有何变化？（3）择期分娩率在人群中的差异程度如何？
我们首先记录了美国、加利福尼亚州和新泽西州剖宫产的长期趋势。然后，我们使用了链接的出生和医院出院记录以及基于联合委员会指南的算法，以识别低风险妊娠，并记录加利福尼亚州和新泽西州在最近20年期间低风险妊娠中剖宫产和引产的趋势，总体情况以及按产妇特征和孕周划分的情况。
在加利福尼亚州和新泽西州的低风险妊娠中，剖宫产和引产率从20世纪90年代初到21世纪中期急剧上升，2007年在加利福尼亚州达到33%的峰值，在新泽西州达到41%的峰值，然后有所下降，且引产后继发剖宫产的比例从不到五分之一增加到约四分之一。更多的教育程度、非西班牙裔白人种族/族裔、在美国出生以及非医疗补助与更高的干预率相关。所有社会经济群体的趋势相似，但在加利福尼亚州，差异一直在缩小。在低风险妊娠的早期（孕周为37 - 38周）分娩中，两个州的择期分娩率在21世纪中期/后期之前都大幅上升，在加利福尼亚州达到约35%的峰值，在新泽西州超过40%的峰值，然后两个州都降至约20%。
鉴于非医学必要剖宫产存在既定的健康风险，低风险妊娠中有相当一部分引产会导致剖宫产，且自21世纪中期达到峰值以来，低风险妊娠中的干预措施并未大幅下降，本文记录的趋势表明，仍需持续甚至加大公共卫生关注力度，以应对美国剖宫产和引产率仍然过高的问题。
