<p>Deidentified JiVitA-1 database.</p>

Prelacteal feeding (PLF)—giving infants food or liquid other than breastmilk within the first 3 days of life—remains common and hinders optimal breastfeeding in Bangladesh. This study assessed changes in PLF practices in rural Bangladesh from 2004 to 2019 and examined associate household, maternal, and infant factors. We analyzed data from two cluster-randomized trials in rural northwest Bangladesh (n = 16,551; n = 4,401). Trained staff collected sociodemographic and birth data through household visits. We used multivariable logistic regression to examine associations between household, maternal, and infant characteristics and PLF and a non-linear approximation of the Oaxaca-Blinder regression decomposition to understand the factors associated with the changing prevalence of PLF. The prevalence of PLF declined from 89% in 2004 to 24% in 2019. Factors associated with PLF shifted over time, particularly household wealth, infant sex, and birth weight. Institutional delivery (OR=0.27; 95% CI 0.22, 0.32 in 2004; OR=0.78; 95% CI 0.61, 1.00 in 2019) and multigravida status (OR=0.68; 95% CI 0.58, 0.79 in 2004; OR=0.73; 95% CI 0.58, 0.93 in 2019) were consistently associated with reduced odds of PLF across cohorts in the multivariable analysis. The decomposition analysis based on the two trials indicated that changes in prevalence of the covariates explained 15% of the decrease in prevalence of PLF, primarily accounted for by increases in health facility deliveries (86%), increases in infant birth weight (13%), and increasing gravidity (12%). 85% of the change remains unexplained by the measured variables. The prevalence of PLF declined considerably in rural Bangladesh over the 15-year period. There are shifts in factors associated with PLF overtime. Improvements in socio-demographic factors played a modest but meaningful role in reducing PLF. However the majority of the reduction remains unexplained by the measured variables. Further research is needed to identify other potential drivers for changes in the prevalence of PLF.初乳前喂养（Prelacteal feeding, PLF）指在婴儿出生后3天内给予其母乳以外的食物或液体，该做法在孟加拉国仍较为普遍，且会阻碍最优母乳喂养的实施。本研究评估了2004年至2019年孟加拉国农村地区初乳前喂养实践的变化趋势，并考察了相关家庭、产妇及婴儿层面的影响因素。研究分析了孟加拉国西北部农村地区两项整群随机试验（cluster-randomized trials）的数据，样本量分别为16551例和4401例。经过培训的研究人员通过入户访谈收集了社会人口学特征及出生相关数据。本研究采用多变量logistic回归（multivariable logistic regression）分析家庭、产妇及婴儿特征与初乳前喂养之间的关联，并使用非线性近似奥萨卡-布林德回归分解（Oaxaca-Blinder regression decomposition）法，探究与初乳前喂养患病率变化相关的影响因素。初乳前喂养的患病率从2004年的89%下降至2019年的24%。与初乳前喂养相关的影响因素随时间发生了显著变化，其中尤以家庭财富水平、婴儿性别及出生体重最为突出。多变量分析显示，住院分娩（2004年比值比（Odds Ratio, OR）=0.27，95%置信区间（Confidence Interval, CI）0.22~0.32；2019年OR=0.78，95%CI 0.61~1.00）及经产产妇身份（2004年OR=0.68，95%CI 0.58~0.79；2019年OR=0.73，95%CI 0.58~0.93）在两个队列中均与初乳前喂养的发生风险降低持续相关。基于两项试验的分解分析表明，协变量的变化可解释初乳前喂养患病率下降的15%，其中主要贡献来自住院分娩比例的提升（86%）、婴儿出生体重的增加（13%）以及孕次的增加（12%），剩余85%的变化无法通过已测量的变量得到解释。在15年的研究周期内，孟加拉国农村地区的初乳前喂养患病率出现了显著下降，其相关影响因素也随时间发生了转变。社会人口学因素的改善在降低初乳前喂养比例方面发挥了适度但具有意义的作用，但绝大多数的患病率下降仍无法通过已测量的变量得到解释。未来仍需开展进一步研究，以明确初乳前喂养患病率变化的其他潜在驱动因素。