Lamm Steven H, Ferdosi Hamid, Boroje Isabella J, Afari-Dwamena Nana Ama, Qian Lu, Dash Elisabeth Dissen, Li Ji, Chen Rusan, Feinleib Manning
Center for Epidemiology and Maternal and Child Health, Consultants in Epidemiology and Occupational Health (CEOH), Washington, DC, USA.
Department of Health Policy and Management, Johns Hopkins University-Bloomberg School of Public Health, Baltimore, MD, USA.
Prev Med Rep. 2020 Mar 10;18:101080. doi: 10.1016/j.pmedr.2020.101080. eCollection 2020 Jun.
Small for gestational age (SGA) is a well-known consequence of maternal smoking. Here, we newly examine the magnitude of SGA risk by week of gestational age.
Singleton live births (N = 3,032,928) with recorded birth weight, gestational age (22-44 weeks), and maternal tobacco use (Y/N) were categorized as to SGA (Y/N), based on 10th percentile gender-specific weights-for-age.
SGA prevalence among tobacco users (19.5%) and non-users (9.1%) yielded a significant SGA prevalence rate ratio of 2.15 (2.13-2.16) and a significant adjusted odds ratio of 2.36 (2.34-2.38). The tobacco non-users' rate was steadily near 9% across the week 22-44 gestational age range. The tobacco users' rate was steady until week 33 when it rose monotonically through week 37 to about 20% at week 38 and remained high. This pattern for SGA by gestational week was similar for prevalence rates and adjusted ORs. Tobacco use only through week 33 was not seen to be an SGA risk factor. The magnitude of tobacco use as an SGA risk factor for late third trimester births increased during the period of preterm birth and became fully evident with a two-fold risk for full term infants.
We newly report the temporal pattern of tobacco-related SGA by week of gestational age. Tobacco-related SGA was only seen for late third trimester births - increasing during weeks 33-37 with a doubling during weeks 38-44. This pattern, informative for issues of mechanism, highlights the potential benefit of extending tobacco cessation programs through the third trimester of pregnancy.
小于胎龄儿（SGA）是孕妇吸烟的一个众所周知的后果。在此，我们重新按孕周检查SGA风险的程度。
根据第10百分位的特定性别年龄体重，将记录了出生体重、孕周（22 - 44周）和孕妇吸烟情况（是/否）的单胎活产（N = 3,032,928）分为SGA（是/否）。
吸烟者中SGA的患病率（19.5%）和非吸烟者中SGA的患病率（9.1%）得出显著的SGA患病率比为2.15（2.13 - 2.16），以及显著的调整优势比为2.36（2.34 - 2.38）。在孕周22 - 44周范围内，非吸烟者的患病率稳定在9%左右。吸烟者的患病率在33周前保持稳定，之后在33至37周单调上升，在38周时达到约20%并保持高位。这种按孕周划分的SGA模式在患病率和调整后的优势比方面相似。仅在33周前吸烟未被视为SGA的危险因素。对于晚期孕晚期出生的婴儿，吸烟作为SGA危险因素的程度在早产期间增加，对于足月婴儿，其风险翻倍时变得完全明显。
我们首次报告了按孕周划分的与烟草相关的SGA的时间模式。与烟草相关的SGA仅在孕晚期出生时出现 - 在33 - 37周增加，在38 - 44周翻倍。这种模式对于机制问题具有参考价值，突出了在妊娠晚期延长戒烟计划的潜在益处。
