PURPOSE To assess associations of theoretically reallocating time from sleep, sedentary behavior, or light intensity physical activity (LPA) to moderate/vigorous intensity physical activity (MVPA) during pregnancy with infant growth outcomes. METHODS We used data from a cohort of pregnant individuals with overweight or obesity (n = 116). At 9-15 and 30-36 weeks gestation, waking movement was measured using wrist-worn accelerometers and sleep duration was self-reported. Outcomes were obtained from delivery electronic health records (birth) and study visits (12 months). We used compositional isotemporal substitution models. RESULTS In early pregnancy, reallocating 10 minutes of sleep, sedentary behavior, or LPA to MVPA was associated with 20% (RR = 0.80; 95%CI: 0.75,0.85), 21% (RR = 0.79; 95%CI: 0.75,0.84), and 25% (RR = 0.75; 95%CI: 0.70,0.81) lower risk of large-for-gestational age (LGA) birthweight, respectively, and 17% (RR = 0.83; 95%CI: 0.75,0.91), 18% (RR = 0.82; 95%CI: 0.75,0.91), and 22% (RR = 0.78; 95%CI: 0.70,0.88) lower risk of rapid infant growth (birth to 12 months), respectively. In late pregnancy, reallocating 10 minutes to MVPA was associated with 18% to 22% lower risk of LGA birthweight, but was not associated with rapid infant growth. Reallocating time to MVPA in early or late pregnancy was not associated with high newborn body fat percent. CONCLUSIONS Our findings suggest beneficial associations of theoretically reallocating time from sleep, sedentary behavior, or LPA to MVPA, especially during early pregnancy, for reducing LGA birthweight and rapid infant growth.

中文翻译：

---

怀孕 24 小时一天中的理论行为替代和婴儿生长结局。


目的 评估理论上从睡眠、久坐行为或轻强度体力活动 （LPA） 到怀孕期间中等/剧烈强度体力活动 （MVPA） 的时间重新分配与婴儿生长结局的关联。方法 我们使用了来自超重或肥胖孕妇队列的数据 （n = 116）。在妊娠 9-15 和 30-36 周，使用腕戴式加速度计测量清醒运动，并自我报告睡眠持续时间。结局通过交付电子健康记录 （出生） 和研究访问 （12 个月） 获得。我们使用了组合等时间替换模型。结果 在妊娠早期，将 10 分钟的睡眠、久坐行为或 LPA 重新分配给 MVPA 与胎龄前大 （LGA） 出生体重风险降低 20% （RR = 0.80;95% CI： 0.75,0.85）、21% （RR = 0.79;95% CI： 0.75,0.84） 和 25% （RR = 0.75;95% CI： 0.70,0.81） 以及 17% （RR = 0.83;95% CI： 0.75,0.91）、18% （RR = 0.82;95% CI： 0.75,0.91） 和 22% （RR = 0.78;95% CI： 0.70,0.88） 婴儿快速生长 （出生至 12 个月） 的风险分别降低。在妊娠晚期，将 10 分钟重新分配到 MVPA 与 LGA 出生体重风险降低 18% 至 22% 相关，但与婴儿快速生长无关。在妊娠早期或晚期重新分配 MVPA 的时间与新生儿体脂百分比高无关。结论 我们的研究结果表明，理论上将睡眠、久坐行为或 LPA 的时间重新分配到 MVPA，尤其是在怀孕早期，对减少 LGA 出生体重和婴儿快速生长具有有益的关联。