EFFECT OF ENVIRONMENTAL TEMPERATURE ON INCIDENCE OF PREECLAMPSIA AND ECLAMPSIA

Background:Preeclampsia and eclampsia continue to be the one of leading causes of maternal and fetal mortality and morbidity worldwide. As global warming has become major concern all over the world ,there is need of studies to know its impact on womens health. Aim of this study is To observe the effect of environmental temperature on incidence of preeclampsia and eclampsia. Methods and Material: This is a comparitive study to know the effect of hot and cold months on incidence of preeclampsia and eclampsia , conducted in department of Obstetrics and Gynaecology at a tertiary health centre . All the patients admitted in Labor room emergency were included in the study, making total number of 33,267 admissions in 47 months. All records of the patients admitted were reviewed. All the data were arranged month wise on Microsoft excel 2010âˆ™Ink , and calculations were done on this spread sheet. Months were divided into two groups : Hot weather group[ N = 11] comprising of months with average maximum temperature >30ÂºC and Cold weather group[N=9] comprising of months with average maximum temperature â‰¤ 18ÂºC. Temperature range for Hot and Cold weather were in accordance with WHO. Statistical analysis used: Statistic tests used were Chi-square. Results: Of total admissions incidence of pre-eclampsia and eclampsia cases was 2.8%(927/33267).There was no significant effect of hot weather on incidence of pre-eclampsia and eclampsia cases (p > 0.05) while significant effect of cold weather was seen leading to increased incidence of pre-eclapmsia and eclampsia cases (p <0.05). Conclusions: Trend of global warming warrants the need to study the effect of environmental changes on maternal health on large scale.

517 impact on health system, especially of women. To achieve the desired goal of reduction in maternal mortality, environmental impact on health could not be ignored.
Preeclampsia and eclampsia are pregnancy-related high blood pressure disorders.Pregnancy-related hypertension disorder symptoms can include high blood pressure, protein in urine, hand/face swelling, headache, vision problems, abdominal pain, seizures, & nausea/vomiting.Women with preeclampsia are at increased risk for organ damage/failure, preterm birth, pregnancy loss, and stroke.Preeclampsia, formerly called "toxemia of pregnancy," may develop into the more severe condition called eclampsia.
Preeclampsia is a multisystem progressive disorder characterized by the new onset of hypertension and proteinuria or the new onset of hypertension and significant end-organ dysfunction with or without proteinuria in the last half of pregnancy or postpartum. It ismainly caused by maternal and placental vascular dysfunction. Eclampsia refers to the occurrence of a grand mal seizure in a woman with preeclampsia in the absence of other neurological conditions that could account for seizure. Preeclampsia and eclampsia continue to be the one of leading causes of maternal and fetal mortality and morbidity worldwide [2].Pathophysiology of preeclampsia and eclampsia is poorly understood. Factors may include poorly developed uterine placental spiral arterioles which decrease uteroplacental blood flow during late pregnancy. Diffuse or multifocal vasospasm can result in maternal ischemia, eventually damaging multiple organs, particularly the brain, kidneys, and liver. Aim of this study was to observe the effect of environmental temperature on incidence preeclampsia and eclampsia.

Study design and participants
This is a observational comparative study to know theeffect of hot and cold months on incidence of preeclampsia and eclampsia conducted in the department of Obstetrics and Gynecology at a tertiary health centre. Study period was from first of May 2016 to 31st of March 2020 .All the patients admitted in Labor room emergency were included in the study, making total number of 33,267 admissions in 47 months.

Data sources and management
All the records of patients admitted were reviewed. All the data were arranged monthwise on Microsoft excel 2010•Ink , and calculations were done on this spreadsheet. Monthly data were divided into two groups : Hot weather group[ N = 11] comprising of months with average maximum temperature >30ºC and Cold weather group[N=9] comprising of months with average maximum temperature ≤ 18ºC. Data for maximum average temperature for each month and global annual temperature was collected from weather website[3,4]. Temperature range for Hot and Cold weather were in accordance with World Health Organization [5].

Definitions and Measurements
Preeclampsia + Eclampsia case rate is total number of preeclampsia and eclampsia cases per 100 LRE admissions. Preeclampsia was defined as hypertension (≥140/90 mmHg) and proteinuria after 20 weeks of gestation or hypertension plus the involvement of one organ or system in women with previously normal blood pressure[6]. Eclampsia was diagnosed as the presence of new-onset grand-mal seizures in women with preeclampsia[6].

Data analysis
Statistic tests used were Chi-square.

Results:-
Overall number of total admissions in the whole sample was 33,267 with incidence of pre-eclampsia and eclampsia cases 2.8%(927/33267). Number of admissions per month (mean) as compared to whole sample (707.8) was lower in Hot weather(676) and Cold weather(685) groups.
Applying Chi-square showed there was no significant effect of hot weather on incidence of pre-eclampsia and eclampsia cases (p > 0.05) while significant effect of cold weather was seen leading to increased incidence of preeclampsia and eclampsia cases (p <0.05).

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Chi sqare for eclampsia incidence diff in hot and cold weather is 7.1786, p value is 0.007378. Chi sqare for admission per month diff in hot and cold is 12.4055 and p-value is 0.000428 3.3% (206/6166) µ = 2.7 σ = 0.71 X 2 = 5.3884 P = 0.020271 µ= mean for N numbers of values in each group(n/N). σ = standard deviation. X 2 = Chi square value. N= number of months in each group. n = total number of patients in various category of each group.

Discussion:-
The incidence of preeclampsia and eclampsia was similar to other study done in low middle income countries [7].There was also significant increase in cases of preeclampsia and eclampsia( nearing delivery , at delivery or post-delivery ) during Cold weather, findings were similar to other studies [8,9,10]. This warrants special care and blood pressure monitoring for maternal patients conceived in warm climate as they will spend their maximum part of gestation period during hot and moderate months while their expected date of delivery will be in December and January(cold months).Pre-eclampsia has a complex pathophysiology, the primary cause being abnormal placentation. Defective invasion of the spiral arteries by cytotrophoblast cells is observed during preeclampsia. These events leading to preeclampsia start in early pregnancy during which change in environmental temperature may play a role, as evident in this study.

Conclusion:-
Trend of global warming warrants the need to study the effect of environmental changes on maternal health on large scale.