Department of Health Promotion Sciences, University of Palermo, Palermo, Italy.
BMC Public Health. 2011 Oct 19;11:817. doi: 10.1186/1471-2458-11-817.
Infant mortality rate (IMR) is a key public health indicator. Maternal age is a well-known determinant of pregnancy and delivery complications and of infant morbidity and mortality. In Italy the Infant Mortality Rate was 3.7/1000 during 2005, lower than the average IMR for the European Union (4.94/1000). Sicily is the Italian region with the highest IMR, 5/1000, and neonatal mortality rate (NMR), 3.8/1000, with substantial variation among its nine districts. The present study compared a high IMR/NMR district (Messina) with a low IMR/NMR district (Palermo) during the period 2004-2006 to evaluate potential determinants of the IMRs' differences between the two districts and specifically the impact of maternal age.
The Death Causes Registers identified all deaths during the first year of life recorded among infants born to residents of the two districts in 2004-2006. For every case, available hospital charts records were abstracted using a standardized form designed to capture information on potential determinants of infant death. For each district and for each year, IMRs and NMRs were computed. Chi-squared statistics tested the significance of differences between district-specific IMRs. A Poisson regression model was used to analyze the relationship between maternal age, district of residence and IMR.
The 246 death registry-confirmed cases included 143 (58.1%) males and 103 (41.2%) females, with mean age at death of 33.3 days (SD: 64.5, median: 5.5). The average IMR for 2004-2006 was significantly higher for the Messina district than for the Palermo district (p = 0.0001). The IMR ratio was 1.6 (95%CI: 1.2 - 2.1). The IMRs declined from 2004 to 2006. A significant interaction (p = 0.04) between maternal age and district of residence was documented.
The association between advanced maternal age and infant deaths in the Messina district was due in part to the excess of newborns from advanced age mothers, but also to increased risk of death among such newborns. The significant interaction between district of residence and maternal age indicated that the IMR excess in the Messina district cannot be explained by disproportionately high live birth rates among older mothers and suggested the hypothesis that health care facilities in the Messina district could be less well prepared to provide assistance to the excess of high risk pregnancies and deliveries, as compared to Palermo district.
婴儿死亡率（IMR）是一个关键的公共卫生指标。产妇年龄是妊娠和分娩并发症以及婴儿发病率和死亡率的一个已知决定因素。意大利 2005 年的婴儿死亡率为 3.7/1000，低于欧盟的平均 IMR（4.94/1000）。西西里岛是意大利婴儿死亡率最高的地区，为 5/1000，新生儿死亡率（NMR）为 3.8/1000，其 9 个区之间存在很大差异。本研究比较了 2004-2006 年期间婴儿死亡率/新生儿死亡率较高的地区（墨西拿）和婴儿死亡率/新生儿死亡率较低的地区（巴勒莫），以评估两个地区之间 IMR 差异的潜在决定因素，特别是产妇年龄的影响。
死因登记册确定了 2004-2006 年间出生在这两个地区的居民中记录在案的所有 1 岁以下儿童的死亡情况。对于每个病例，使用标准化表格提取了可用的医院图表记录，以获取有关婴儿死亡潜在决定因素的信息。对于每个地区和每个年份，计算了 IMR 和 NMR。卡方检验检验了地区特异性 IMR 之间差异的显著性。使用泊松回归模型分析了产妇年龄、居住地和 IMR 之间的关系。
246 例死亡登记册确认的病例中，男性 143 例（58.1%），女性 103 例（41.2%），死亡时平均年龄为 33.3 天（SD：64.5，中位数：5.5）。2004-2006 年期间，墨西拿地区的平均 IMR 明显高于巴勒莫地区（p=0.0001）。IMR 比值为 1.6（95%CI：1.2-2.1）。IMR 从 2004 年到 2006 年下降。记录到产妇年龄和居住地之间存在显著的交互作用（p=0.04）。
墨西拿地区产妇年龄较大与婴儿死亡之间的关联部分归因于高龄产妇新生儿数量过多，但也归因于这些新生儿死亡风险增加。居住地和产妇年龄之间存在显著的相互作用表明，墨西拿地区的 IMR 过多不能用高龄母亲的活产率不成比例地高来解释，并提出了这样的假设，即与巴勒莫地区相比，墨西拿地区的医疗保健设施可能准备不足，无法为过多的高危妊娠和分娩提供帮助。
