Neonatal mortality, cold weather, and socioeconomic status in two northern Italian rural parishes, 1820–1900

Abstract

BACKGROUND Cold-related conditions represent one of the most common causes of neonatal death in many developing countries. The effects of cold external temperatures on neonatal mortality at the onset of demographic transition recently have attracted scholarly interest. OBJECTIVE First, we aim to study the effects of cold temperatures on neonatal mortality at the onset of demographic transition, focusing on two Italian rural parishes between 1820 and 1900. Second, we aim to assess whether the effects vary according to socioeconomic status (SES), especially among the most vulnerable social groups. METHODS We apply logistic regression and discrete-time event history analysis using micro-data from parish registers and daily records of external temperature. RESULTS The risk of death during the first month of life varied according to external temperature's variation and to socioeconomic status, demonstrating that neonates born to landless rural labourers generally suffered a higher neonatal mortality risk during winter and, more specifically; in case of low temperature at the childbirth during coldest months. CONCLUSIONS The risk of neonatal death increased as external temperatures decreased. The clear influence of temperature on the day of birth suggests that low temperatures on the day of birth exerted a fundamental scarring effect on children's survival. We also find significant differences in neonatal mortality by SES, resulting in more pronounced effects from season and temperature in rural proletarian families. The results show that

The association between cold extremes and neonatal mortality in Swedish Sápmi from 1800 to 1895

“…Compared to other studies of the association between seasonality and neonatal mortality among historical populations [11,19], neonatal mortality in Sápmi did not reveal a pronounced U-profile of neonatal mortality by month of birth. This can be explained by the differences in climate between northern Sweden and the Mediterranean countries, in which the former has shorter and cooler summers and longer, colder winters.…”

“…The neonatal mortality rates presented in this article are lower, or much lower, compared to other historical populations. For example, in Italy, the neonatal mortality rate during the nineteenth century was almost twice as high [11] as the neonatal mortality rate in Sápmi.…”

“…Another mechanism that could link cold weather conditions with neonatal mortality is the disease panorama in northern Sweden. Previous research on the association between season, temperature extremes and neonatal mortality among historical populations has mainly been conducted in Italy and Spain [11,[17][18][19][27][28][29]. These countries have longer hotter summers and shorter milder winters, whereas northern Sweden has longer colder winters and shorter cooler summers.…”

“…Studies conducted in contemporary societies have shown that extreme low temperatures are associated with higher infant mortality in Arctic populations [9] and with an increase in sudden infant deaths [10]. For historical populations, previous studies have identified socio-economic differences with regards to vulnerability to temperature extremes on infant and neonatal mortality, in which the effect of low temperatures was more pronounced among the lowest social groups [1,11]. However, differences in vulnerability to temperature extremes between ethnic groups living in the same area are still poorly understood.…”

Season of birth, stillbirths, and neonatal mortality in Sweden: the Sami and non-Sami population, 1800–1899

“…For instance, a poor diet during pregnancy can affect the immune system of the foetus, exposing the newborn to infections of the digestive tract after weaning, especially during warm summers. On the other hand, infants of poorly nourished mothers are prone to be of low birth weight and at a risk of dying from hypothermia, especially during cold winters [47,48]. In Swedish rural communities, food supplies were scarcer in spring and early summer, especially after poor harvests in the previous year, causing a diet that was inferior compared to that of other seasons [16,49].…”