Poster #23 - The Association Between Weather Variability and Birth Outcomes: A Registry Based Study from Tanzania

• In Event: 3-106 - Poster Session 11
  In Poster Session: PS 11 Section - Biological Processes: Psychophysiology

Integrative Statement

Pregnancy complications and poor birth outcomes are public health problems, causing considerable morbidity and mortality for mothers and their children. According to the WHO, in 2015 more than 2.6 million stillbirths were caused by negative birth outcomes. The effect of environmental conditions such as temperature, air humidity and the seasons on the incidence of pregnancy disorders like preeclampsia has been documented. However, less is known about the effects on health at birth of intrauterine exposure to extreme temperature changes. Some studies have reported that African women are at increased risk of poor birth outcomes, but it is not clear to which extent weather conditions, particularly draughts, contribute to it. Our study aims to investigate the extent to which weather variability (wet season and dry season) are associated with neonatal birthweight, neonatal length, neonatal head circumference and Apgar scores.

Methods: A non-clinical sample of women (N=22,867) were assessed by means of an interview 24 hours postpartum for social-demographic characteristics, reproductive history, pregnancy and birth characteristics such as maternal health before and during pregnancy, complications during labour and delivery, and newborn health status. Weather variability was based on the precipitation and on the normalized difference vegetation index (NDVI) recorded in the Kilimanjaro region for the period of interest. Our sample includes mothers who delivered at Kilimanjaro Christian Medical Centre (KCMC), Tanzania from January 2001 to June 2015. Exclusion criteria were premature delivery, poor general health, multifetal pregnancies and those with missing information on weight and height.

Results: Neonatal birthweight was significantly associated with higher NDVI recorded on the 2nd pregnancy trimester (B=4.76, p=.04) and with increased precipitation on the 3rd trimester (B=.22, p=.00); neonatal length was significantly associated with NDVI at the 3rd trimester (B=.01, p=.01); neonatal head circumference was positively associated with higher NDVI at the 1st trimester (B=.02, p=.00) and with precipitations on the third trimester (B=.00, p=.00). The analyses controlled for several covariates (e.g. maternal diseases, maternal weight, height and age). No associations were found between weather variability and Apgar scores.

Conclusions: Exposure to extreme temperatures has harmful effects on human health. Our results suggest that birth weight, neonatal length and head circumference are positively affected by contact with increased precipitation and negatively affected by exposure to draughts during pregnancy. Being exposed to extreme heat in this critical period of human development may have lasting adverse effects.

Authors

• Rita Amiel Castro, University of Zurich
  Presenting Author

• Ulrike Ehlert, University of Zurich
  Non-Presenting Author