Journal of Womens Health, Issues and Care ISSN: 2325-9795

All submissions of the EM system will be redirected to Online Manuscript Submission System. Authors are requested to submit articles directly to Online Manuscript Submission System of respective journal.

Research Article, J Womens Health Issues Care Vol: 3 Issue: 6

Prevalence and Risk Factors for Symptoms Suggestive of Pre-Eclampsia in Indian Women

Sutapa Agrawa* and Gagandeep K Walia
1South Asia Network for Chronic Disease, Public Health Foundation of India, India
Corresponding author : Sutapa Agrawal
Epidemiologist, South Asia Network for Chronic Disease, Public Health Foundation of India, Plot no 47, Sector 44, Gurgaon, Haryana-122002, India
Tel: 0124- 4781400 Ext– 4419; M: +919650155334
E-mail: [email protected]
Received: May 09, 2014 Accepted: October 08, 2014 Published: October 12, 2014
Citation: Agrawal S, Walia GK (2014) Prevalence and Risk Factors for Symptoms Suggestive of Pre-Eclampsia in Indian Women. J Womens Health, Issues Care 3:6. doi:10.4172/2325-9795.1000169

Abstract

Prevalence and Risk Factors for Symptoms Suggestive of Pre-Eclampsia in Indian Women

Pre-eclampsia is a serious health implication in pregnancy accounting for severe illness among women especially in LMICs. We examined the prevalence of symptoms suggestive of pre-eclampsia and associated maternal, behavioural, and socioeconomic and demographic risk factors in Indian women.

Keywords: Pre-eclampsia; Symptoms; Risk factors; Women; India; NFHS-3

Keywords

Pre-eclampsia; Symptoms; Risk factors; Women; India; NFHS-3

Introduction

Preeclampsia, a life threatening complication of pregnancy is a condition that typically starts after 20th week of pregnancy and is related to increased blood pressure (BP ≥140/90 mmHg) and protein in mother’s urine (urinary albumin protein ≥ 300 mg/24 h). The clinical spectrum of pre-eclampsia ranges from mild to severe. Pre-eclampsia occurs in 5-8% of pregnancies worldwide, and is the second leading cause of direct maternal and fetal deaths [1]. The etiology of preeclampsia is still obscure, despite many attempts to identify possible causes. Women with moderate pre-eclampsia generally have no symptoms. Women with severe pre-eclampsia may present with symptoms such as headache, upper abdominal pain, or visual disturbances and have raised blood pressure, ankle oedema and proteinuria [2].The prevalence of pre-eclampsia varies in different populations and in different ethnic groups [1].
Pre-eclampsia has remained a significant public health threat in both developed and developing countries contributing to maternal and perinatal morbidity and mortality globally [2]. Numerous risk factors for pre-eclampsia have been suggested but only some have actually been established in statistical models that permit simultaneous control for possible confounders. There has not been any previous large-scale report concerning the prevalence and risk factors for pre-eclampsia in a nationally representative Indian population. Therefore, the objective of the present study is to identify population based risk factors associated with pre-eclampsia in a large sample of Indian women. India’s third National Family Health Survey (NFHS-3,2005-06) collected data from 124,385 women residing in 109,041 households and covered regions comprising more than 99% of India’s population which provides a unique opportunity to study the prevalence of pre-eclampsia, its socio-demographic, maternal, and lifestyle determinants. In this paper, we report the findings on self-reported symptoms of pre-eclampsia, and the risk factors associated with it.

Materials and Methods

Data
Cross-sectional data from India’s third National Family Health Survey (NFHS-3) conducted during 2005-06 was used for this study. NFHS was designed on the lines of the Demographic and Health Surveys (available at www.dhsprogram.com) that have been conducted in many developing countries since the 1980s. NFHS has been conducted in India for three successive rounds, each at an interval of 5 years. NFHS-3 collected demographic, socioeconomic and health information from a nationally representative probability sample of 124,385 women aged 15–49 years residing in 109,041 households. The sample is a multistage cluster sample with an overall response rate of 98%. All states of India are represented in the sample (except the small Union Territories), covering more than 99% of the country’s population. Full details of the survey have been published [3]. The analysis presented here focuses on 39,657 ever married women who had a live birth in the five years preceding the survey and reported specific health problems during pregnancy for the most recent birth.
Outcome measures
In NFHS-3, during the time of personal interview, several questions were asked to women related to health problems during pregnancy for the most recent live birth only (to account for recall lapse) in the five years preceding the survey. The question asked were: “During this pregnancy, did you have difficulty with your vision during daylight?” or “During this pregnancy, did you have swelling of the legs, body or face?” The response options were “yes”, “no”, and “don’t know”. According to the World Health Organisation’s Integrated Management of Pregnancy and Childbirth guidelines for midwives and doctors on Managing Complications in Pregnancy and Childbirth (2000) and National Institute for Health and Care Excellences’ (NICE) guidelines for management of hypertensive disorders during pregnancy (2010), women who reported difficulty with vision during daylight, and swelling of the legs, body, or face, were coded as having symptoms of pre-eclampsia in this study. However, no effort was made to confirm clinical diagnosis of these health problems from the respondents and thus ascertainment of preeclampsia was not possible in the survey. The survey was conducted using an interviewer-administered questionnaire in the native language of the respondent using a local, commonly understood term for all the health problems during pregnancy. A total of 18 languages were used with back translation to English to ensure accuracy and comparability.
Covariates
Potential covariates/risk factors were selected on the basis of previous knowledge of their association with pre-eclampsia. The socio-demographic factors considered in the present analysis included age (15-29, 30-39, 40-49 years); education (no education, primary, secondary, higher); religion (Hindu, Muslim, Christian, Sikhs, Others); caste/tribe (Scheduled Castes, Scheduled Tribes, Other Backward Class, Forward class, missing caste); employment status (currently not working, working); wealth index (measured by an index based on household ownership of assets and graded as lowest, second, middle, fourth and highest) was computed using previously described methods3;place of residence (urban, rural); and geographic regions (north, northeast, central, east, west, south). The following maternal reproductive risk factors were evaluated as potential confounding factors: total children ever born (CEB) (1, 2-3, 4+); birth interval (first birth order, interval <2years, interval 2-3years, interval 3+years); antenatal care (ANC) visit during pregnancy (no visit, 1 visit, 2 visits, 3 visits, 4+ visits); blood pressure measured during pregnancy (no, yes); received advise on pregnancy nutrition during ANC visit (no, yes); alerted to pregnancy complications such as convulsions (no, yes); type of pregnancy (singleton, twin); ever had a terminated pregnancy (no, yes); anemia level (not anaemic, mild, moderate, severe). The biological and lifestyle factors included Body Mass Index (BMI) kg/m2 (based on Indian adult population standard categories): ≤18.4 kg/m2 (underweight), 18.5 to 22.9 kg/m2 (normal), 23.0 to 24.9 kg/m2 (overweight), ≥25 kg/m2 (obese); current tobacco smoking (no, yes); alcoholic (no, yes);self-reported diabetes (no, yes); and self-reported asthma (no, yes). For definition of some variables see Table 2.
Statistical analysis
Descriptive statistics were calculated with the use of standard methods. Differences in categorical variables were tested using Pearson’s χ2 tests. A p-value of<0.05 was considered statistically significant. The regional and rural/urban differentials in the prevalence of pre-eclampsia was first examined and then the prevalence of preeclampsia and its unadjusted associations with eight socioeconomic and demographic variables, nine maternal factors, and five BMI and lifestyle and chronic disease related factors was explored and reported. Multiple logistic regression analysis was restored to estimate the prevalence odds ratios for each of these risk factors for symptoms suggestive of pre-eclampsia, in unadjusted and adjusted models. As certain states and certain categories of respondents were oversampled, in all analyses sample weight was used to restore the representativeness of the sample.
Results are presented as odds ratios with 95% confidence intervals (OR;95%CI). The estimation of confidence intervals takes into account design effects due to clustering at the level of the primary sampling unit. Before carrying out the multivariate model, the possibility of multicollinearity between the covariates we assessed. In the correlation matrix of covariates, all pair wise Pearson correlation coefficients were found <0.5, suggesting that multicollinearity did not affect the findings. All analyses including the multiple logistic regression models were conducted using the SPSS statistical software package Version 19(IBM SPSS Statistics, Chicago, Illinois, USA).
Ethical considerations
The NFHS-3 survey received ethical approval from the International Institute for Population Science’s Ethical Review Board and Indian Government. Prior informed written consent was obtained from each respondent. The analysis presented in this study is based on secondary analysis of existing survey data with all identifying information removed.

Results

Table 1 shows the findings for prevalence of symptoms suggestive of pre-eclampsia by India’s state and rural/urban residence. Almost one-third of the respondents (n=11,362; 28.7%) had reported symptoms suggestive of pre-eclampsia (6.3% had difficulty with vision during daylight and 25.1% had swelling of the legs, body or face) with a slightly higher prevalence in urban India (31.8%); higher rates (>40%) were observed in the states of Uttarakhand, Jharkhand, Meghalaya, Mizoram, Sikkim, Kerala and highest in Tripura (49.4%).
Table 1: Self-reported prevalence of symptoms suggestive of pre-eclampsia during pregnancy among women aged 15-49 years (n=39,657) for the most recent live birth in the five years preceding the survey, by state and residence, India, 2005-06.
Table 2 shows the associations between maternal, lifestyle, dietary and socioeconomic characteristics and symptoms suggestive of pre-eclampsia in Indian women. Strong associations (p<0.0001) between different factors and prevalence of symptoms suggestive of pre-eclampsia have been found: twin pregnancy (40.9%), terminated pregnancy (33.2%), whether alerted to pregnancy complications such as convulsions (36.2%), severe anemia (33.7%), obesity (35.8%), current tobacco smoking (37.2%), diabetes (40.5%), asthma (41.7%), among Muslim (33.5%) and Christian women (34.6), and women residing in eastern part of India (33.1%).
Table 2: Sample distribution and self-reported prevalence of symptoms suggestive of pre-eclampsia during pregnancy among women aged 15-49 years (n=39,657) for the most recent live birth in the five years preceding the survey according to selected characteristics, India, 2005-06
With various risk factors and socioeconomic and demographic characteristics statistically controlled (Table 3), the likelihood of reporting symptoms suggestive of pre-eclampsia was higher among those women whose blood pressure was measured during pregnancy (OR:1.14;95%CI:1.06-1.22;p<0.0001), who received advise on pregnancy nutrition during ANC visit (OR:1.21;95%CI:1.13- 1.29;p<0.0001), were alerted to pregnancy complications such as convulsions during ANC visits (OR:1.25;95%CI:1.16-1.34;p<0.0001), twin pregnancy (OR:1.50;95%CI:1.12-2.09;p=0.009), had a terminated pregnancy (OR:1.23;95%CI:1.15-1.31;p<0.0001), had severe anemia (OR:1.41;95%CI:1.15-1.72;p<0.0001), among obese women (OR:1.32;95%CI:1.20-1.46;p<0.0001), tobacco smoking(OR:1.78;95%CI:1.35-2.35;p<0.0001), diabetes (OR:1.65;95%CI:1.32-2.07;p<0.0001) or asthma (OR:1.64;95%CI:1.31- 2.06;p<0.0001) with reference to their counterparts. The likelihood of reporting symptoms suggestive of pre-eclampsia was also significantly higher among Muslim (OR:1.33;95%CI:1.23-1.44;p<0.0001) and Christian women(OR:1.41;95%CI:1.17-1.68;p<0.0001) but moderately significant among women belonging to Other backward class (OR:1.08;95%CI:1.00-1.17;p=0.051), and women residing in central(OR:1.09;95%CI:0.99-1.20;p=0.081) India. However, women who had one or more ANC visits during pregnancy (OR ranges from 0.75 to 0.89), women who were underweight (OR:0.88), and resides in southern region of India (OR:0.75), had a lower odds of pre-eclampsia prevalence(p<0.0001).
Table 3: Unadjusted and adjusted odds ratios (ORs) and 95% confidence interval (95%CI) for the symptoms suggestive of pre-eclampsia during pregnancy among women age 15-49 years for the most recent birth in the five years preceding the survey, India, 2005-06.

Discussion

In this nationwide large scale cross-sectional study, three main sets of findings identified relating to (i) overall prevalence of selfreported symptoms suggestive of pre-eclampsia; (ii) geographical differences in prevalence; and (iii) risk factors for prevalence.
Firstly, the prevalence of symptoms suggestive of pre-eclampsia (30.3%) in this large nationally representative survey was found very high compared to an earlier study in an Asian population [9] (preeclampsia prevalence was 1.4% (n=415) among 29375 Taiwanese women recruited in a retrospective cohort study) and other Indian hospital based case-control studies. This may be due to the study’s use of cross-sectional, self-reported symptoms of pre-eclampsia rather than direct, clinical measurement of actual pre-eclampsia through biological samples. A recent secondary analysis of the WHO Global Survey on Maternal and Perinatal Health in 24 low and middle-income countries [16] found the prevalence of preeclampsia/ eclampsia in the study population to be 4% (n=10,754). Secondly, striking differences, geographically and between specific states regarding prevalence of pre-eclampsia symptoms was found. Prevalence ratios for pre-eclampsia symptoms showed almost three fold variation between the lowest prevalence state (Haryana-18.5%) and highest prevalence state (Tripura-49.4%). These substantial statewise differences in pre-eclampsia prevalence clearly warrant further investigation. State specific analysis using multilevel methods could be carried out to explore the substantial differences in prevalence in Indian states. Some potential explanations for these differences might be that in high prevalence states there is a very high rate of smoking particularly among rural women, high prevalence of diabetes and more terminated pregnancy cases along with a high schedule tribe population coupled with poorer access to health care services (expect for Kerala) compared to rest of India. An alternative explanation may be related to climatic differences across Indian regions and states. Some studies in USA have reported a higher incidence of preeclampsia associated with conception during the spring and summer months [17-18]. Potential mechanisms include seasonal variation in exposure to infections, dietary changes, and alteration in vitamin D regulation and calcium metabolism as a consequence of exposure to sunlight, which are, in turn, associated with blood pressure levels [17].
Thirdly, a number of specific risk factors for prevalence of symptoms suggestive of pre-eclampsia were identified in this study. Some of the risk factors for pre-eclampsia symptoms among Indian women are similar as found among Asian women [9] or those of other ethnic groups, while some vary. It is well-established that the risk of pre-eclampsia is greater in twin [19-20] rather than in singleton pregnancies and similar result is found in the present study. The reported incidence of pre-eclampsia is 13%-37% in multiple pregnancies, which is 2-3 times higher than singleton pregnancies [21-22].The finding that obese women are at a higher risk of preeclampsia is similar to studies which showed obesity is a risk factor for pre-eclampsia [23-25], but the mechanisms involved are not known. Women with the lowest BMI have relatively lower preeclampsia prevalence [26], which is also confirmed in the present study (OR:0.88; CI:0.83-0.93).
The finding that current tobacco smoking is associated with significantly increased risk of pre-eclampsia is also consistent with previous research [27-28] though an earlier systematic review analyzing the pooled data from cohort and case-control studies showed a lower risk of preeclampsia associated with cigarette smoking during pregnancy [29-30]. A similar finding with other studies regarding previous history of miscarriage or terminated pregnancy [31-32], ethnicity [33], socio-economic position [34] with pre-eclampsia risk can be found in the present study. The likelihood of progression from gestational hypertension to pre-eclampsia may be increased by a prior miscarriage [35]. However, a minor limitation of the present study is the inability to differentiate between spontaneous and induced abortion because of the lack of information on this variable. Underlying medical conditions [36] such as diabetes [18,37] or asthma [38] is associated with higher prevalence odds of pre-eclampsia and the findings of the present study are consistent with the earlier reports.
In this study, age and parity were not found to be associated with pre-eclampsia in contrast to other studies [39-40]. A study done in Saudi Arabia showed that women at extremes of maternal age, the nulliparous women, and high-parity women are at an increased risk of developing pre-eclampsia [41]. The variation in our study and other studies could be due to the differences in the population-based and hospital based study.
The present study found higher prevalence of pre-eclampsia in women who visited ANC during the pregnancy or who received advice on pregnancy nutrition and were alerted about pregnancy complications such as convulsions during their ANC visit. The identification and counseling of pre-eclampsia relies fundamentally on the frequency of antenatal care [42] and if mother’s blood pressure was measured during the visit. Many women with pre-eclampsia, particularly, at the community level are missed due to the lack of antenatal care. These women are more likely to develop serious complications. Antenatal care utilization is around 68% in LMIC compared to 98% in high resource settings. The region of the world with the lowest levels of use is South Asia, where only 54% of pregnant women have at least one antenatal care visit [43] and in India 22.8% [3]. Not surprisingly, there is marked urban/rural differential in accessing antenatal care in LMIC including India. Whereas 86% of women in urban settings will have one antenatal visit, only 65% of women rural settings will have the same [43]. For repeated antenatal visits, 62.4% of women in urban India report four or more antenatal visits compared to 27.7% of rural women3. But, pre-eclampsia can probably not be predicted, even in populations with high level or resources, thus, it is important that ANC should be available to all women in LMICs where the majority of the burden of pre-eclampsia falls.
Strength and limitations of the study
To the knowledge of the authors, this is the largest nationally representative cross-sectional study of the population based risk factors for pre-eclampsia in an Asian population. The strengths of this study include the large nationally representative study sample allowing comparisons to be made between states and urban versus rural settings, and the ability to examine socio-economic and lifestyle patterning of symptoms of pre-eclampsia risk. Further, the large sample size provided adequate power to identify the potential risk factors for pre-eclampsia and compensated for the ethnic variations in Indian populations. The present study evaluated the association of well-known risk factors as potential confounders and effect modifiers including birth intervals, maternal age, type of pregnancy, diabetes, asthma, body mass index, and tobacco smoking. However, due to the general challenges of measuring hypertensive disorders in population-based studies, the measurement of pre-eclampsia in the NFHS also has apparent limitations. Self-reported symptoms during last pregnancy preceding the survey were used to diagnose pre-eclampsia and therefore, ascertainment of pre-eclampsia was performed symptomatic [4] rather than a clinical context. The information of the symptoms of pre-eclampsia presented here is thus based on women’s self-reports and should therefore be interpreted with care. Although misclassification within this context cannot be excluded, it is unlike that severe pre-eclampsia cases were missed. Also the data for gestational onset of pre-eclampsia was not available in the survey. As this is not a clinical study, only prevalence odds ratios for pre-eclampsia could be performed. Moreover no information is available on the pre-pregnancy pre-eclampsia risk factors of the women as health problems during pregnancy was assessed only for the most recent birth within five years preceding the survey. So there was a time gap between the information on all the covariates/risk factors and pregnancy related health problems. This may be one of the reasons that not much substantial association between some of the important risk factors and pre-eclampsia in this population based survey could not be found which was otherwise proven in clinical studies. For e.g., maternal pre-pregnancy body mass index [44-45], familial aggregation [46] and genetic factors [47] which are important risk factor for pre-eclampsia confirmed in some studies was not available in the database on which the present study is based.
However, the NFHS, by collecting wide-ranging social, demographic, maternal health care factors, BMI, lifestyle, chronic disease and diet data, and being nationally representative, provides a unique opportunity to draw descriptive inferences on the social distribution and patterning of pre-eclampsia risk in Indian women.

Conclusion

Well documented population level studies to assess the determinants of pre-eclampsia are few in India. This study is important because few others have reported prevalence rates based on population-level data, and none reflect the results of analysis carried out through 2007, the latest year for which NFHS data are available. The NFHS dataset is remarkable for its depth in terms of national representation.
Pregnant women in low and middle income countries (LMIC) are amongst the most vulnerable populations in the world. Pre-eclampsia is an important public health problem and cause significant maternal and perinatal morbidity and mortality. Community health care workers, specifically lady health care workers, are an integral part of the health care force in many LMIC and can be employed to provide timely care to women with pre-eclampsia. Prevention strategies should be applied to every pregnant woman since we cannot predict who will develop pre-eclampsia given the limitation in resources. Measuring blood pressure and proteinuria is challenging in LMIC due to financial cost and lack of training. A detection tool that is affordable and can be easily applied is needed.
Our study findings may serve as an important call for health care providers to heighten their awareness of the increased populationlevel risk for pre-eclampsia originating in pregnancy. An increased risk for health problem such as pre-eclampsia underlines the importance of regular healthcare during the pre-conception, antenatal, and interconception periods. More epidemiological research in India should focus on uncovering preventable causes of pre-eclampsia, while public health practice and policy must promote improved access to health care prior and mandatory ANC visit and reduction of social and behavioral risk factors.
In conclusion, pre-eclampsia remains an important maternal health problem in India. This study provides empirical evidence of prevalence of symptoms suggestive of pre-eclampsia and their associated risk factors in India. Our findings from a large nationally representative sample of Indian women indicate that, risk factors for pre-eclampsia exist some of which are modifiable. With the target of the Millennium Development Goal in sight, pre-eclampsia should be identified as a priority area in improving maternal health and thus prevention, early detection and timely management of pre-eclampsia and its risk factors at antenatal care visits is important in order to bring about considerable improvement in maternal and perinatal health in India. Further research to verify accuracy of reporting of symptoms of pre-eclampsia is needed in Indian setting.

Acknowledgments

SA and GKW are supported by a Welcome Trust Strategic Award Grant NumberWT084674. The data for this research were collected by The Demographic and Health Surveys Program (www.dhsprogram.com), under a contract from the U.S. Agency for International Development. The authors acknowledge the support of Macro International (Calverton, MD, USA) and International Institute for Population Sciences (Mumbai, India) for providing access to the 2005–2006 Indian National Family Health Survey 3 data. The authors are also grateful to the anonymous reviewer for their useful suggestions and recommendations on the earlier version of the paper.

References
















































Track Your Manuscript

Media Partners

Associations