Clinical characteristics and sociodemographic factors associated with COVID-19 infection in pregnant women in a maternal and children's public hospital

Rodriguez Huaman, Yda; Contreras, Pavel J; Lozada-Urbano, Michelle

doi:10.5867/medwave.2021.07.8442

Research papers

Medwave 2021;21(7):e8442 doi: 10.5867/medwave.2021.07.8442

Clinical characteristics and sociodemographic factors associated with COVID-19 infection in pregnant women in a maternal and children's public hospital

Yda Rodriguez Huaman, Pavel J Contreras, Michelle Lozada-Urbano

References | Download PDF | Print | A(+) A(-) | Easy read

Key Words: pregnancy, COVID-19, socioeconomic factors

Abstract

Objective
To describe the clinical characteristics and sociodemographic factors associated with COVID-19 among pregnant women in a maternal and children's hospital in Lima, Peru.

Methods
Quantitative observational study. The population under study consisted of pregnant women who attended an emergency room and had a COVID-19 test. These women were assessed for age, gestational age, place of origin, occupation, education, marital status, number of children, previous body mass index, gestational body mass index, tetanus vaccination, prenatal controls, and hemoglobin. After bivariate analysis, a generalized linear regression model was applied.

Results
We included 200 women aged between 18 and 34 years (84.5%) with a median gestational age of 36 weeks. More than half were from Lima (52.5%), most were housewives (79%), had high school education (71.9%), and had a cohabiting marital status (60%). The COVID-19 test positivity was 31.5% by rapid tests. Pregestational body mass index assessment showed that 36.7% of normal weight, 38,1% of overweight, and 30.3% of obese pregnant women had COVID-19 infection. 39.7% of patients with hemoglobin levels greater than or equal to 11 g/dL, 21.2% of patients with values between 10 and 10.9 g/dL, and 20% of patients with values between 7 and 9.9 g/dL had COVID-19 infection. The prevalence ratio (with a 95% confidence interval) found that cohabitation was associated with a lower risk of having COVID-19 infection in pregnant women (prevalence ratio: 0.41, p < 0.001).

Conclusion
Cohabiting pregnant women had a lower risk of COVID-19 infection compared with other marital statuses. Further research is needed to evaluate COVID-19 associated factors in pregnant women and possible sociodemographic or economic factors behind cohabiting marital status association among this population.

Main messages

Factors associated with COVID-19 infection were evaluated in pregnant women attending a maternal and children's hospital in Lima, Peru, in 2021.
Our study identifies that cohabiting marital status behaves as a protective factor of having COVID-19 in pregnant women. The marital status could be an intermediary variable for other social variables.
The main limitation of our study lies in obtaining data from secondary sources such as medical records, the emergency registry book, and prenatal control cards.

Introduction

The physiological and mechanical changes associated with pregnancy increase the likelihood of mother and child infection. A large study of women with COVID-19 found that disease manifestations are usually mild [1], and it has been reported that many pregnant women are asymptomatic [2]. However, other pandemics have shown that pregnant women have been more prone to these infections, such as influenza in 1918 [3] and the H1N1 influenza epidemic in 2009 [4].

The most frequent symptoms of pregnant women with COVID-19 are cough and fever [5],[6],[7]. Other findings include lymphocytopenia, elevated C-reactive protein, and almost 91% of the women gave birth by cesarean section [8]. Cesarean section has been associated with preterm birth, decreased Apgar score at birth, and pneumonia, among others [9].

The severity of disease and death from COVID-19 may be conditioned by risk factors such as obesity (body mass index greater than 35 kg/m²), diabetes, maternal age over 40 years [10], and cardiovascular disease [11]. These factors may lead to an increased risk of miscarriage, prematurity, and fetal growth restriction. A systematic review of case reports and case series mentions that some COVID-19 positive mothers had severe maternal morbidity and/or perinatal death, although most were discharged without any complications [8].

There is still limited research on the factors associated with COVID-19 infection in the general population; nor is it certain that the associations identified can be applied to pregnant women. Moreover, clinical variables are not the only ones implicated in gestational morbidity and mortality outcomes. Studies in Latin America have linked economic support [12] and education to COVID-19 [13]. Other studies that have included sociodemographic variables have associated religion with better perinatal outcomes [14]. A study in Iran with COVID-19 positive pregnant women applied the adjusted general linear model and found that satisfaction with marital life, high educational level, and high income can improve the mental health of pregnant women [15].

Pregnant women may face a higher risk of infection due to their adaptation and the immunosuppressive state of pregnancy. SARS-CoV-2 infection can place women and their children at risk [16],[17]. In this sense, we consider it essential to identify the factors related to COVID-19 in pregnant women to prevent modifiable factors and reduce the probability of such infection. We also know that there is still no proven treatment for mothers, fetuses, or newborns. In this sense, we set out to determine the clinical characteristics and sociodemographic factors associated with COVID-19 in pregnant women in a public maternity ward and a children's hospital in Lima, Peru, between 2020 and 2021.

Methods

Study design and participants

This study presents a quantitative, analytical, cross-sectional, and exploratory design. The population comprises pregnant mothers who attended the emergency service of the Hospital Nacional Docente Madre Niño San Bartolomé from June 2020 to January 2021. The sample is made up of the total study population. Due to the pandemic, the hospital only received pregnant women through the emergency service. These women were attended by the medical and obstetrical staff, underwent a physical examination, laboratory tests, and were subjected to a rapid test (PRIMA Lab SA) to detect IgM and/or IgG antibodies against SARS-CoV-2. The test was taken at the point of care. If necessary, patients were referred to another hospital to complement the study with molecular tests to detect SARS-CoV-2 carriers [18],[19] or to assess further patients presenting positive IgM. All emergency care data were recorded in the medical history record by the staff in charge.

Clinical records and/or the nursing emergency record book of pregnancies with laboratory-confirmed COVID-19 were reviewed. Information on sociodemographic and biochemical data was obtained from the clinical records. The dependent variable was being positive or not for COVID-19. The covariates included were age, gestational age, place of origin, occupation, educational level, marital status, number of children, previous body mass index, gestational body mass index, prenatal controls, hemoglobin, and COVID-19 symptoms.

Statistical analysis

A descriptive analysis was performed, obtaining frequency measures for categorical variables and central tendency and dispersion parameters for numerical variables according to the data distribution. Hypothesis testing was performed through a Chi-square test. Subsequently, a generalized linear Poisson family model and log function developed an association analysis with bivariate regression for each potentially associated factor, in addition to a multiple regression that included all the potential associated variables. The 95% confidence interval was used, and a p < 0.05 was considered statistically significant. No confounding or interaction variables were identified during the statistical analysis. The statistical package used was STATA V17.0 (StataCorp. 2021. Stata Statis- tical Software: Release 17. College Station, TX: StataCorp LLC).

Results

Data from 200 pregnant women who attended emergency care at a maternity center in Lima were evaluated. A total of 31.5% (71) were positive for the COVID-19 rapid test. Table 1 shows the mother's characteristics. Eighty-four percent of the women were between 18 and 34 years old. Fifty-two percent lived in Lima, 79% worked as housewives, 71.9% had a secondary school education, and 60% cohabitated. Pregestational body mass index assessment showed that almost half had normal weight, 36.1% were overweight, and 1.5% were obese. We also found that 77.3% had hemoglobin greater than or equal to 11 g/dL and that the majority (97%) were asymptomatic.

Table 1. General characteristics of pregnant women attended in the HDMNSB.

Table 2 shows the hypothesis test, where the place of origin and marital status shows a significant difference (p < 0.05) between the two study groups.

Table 2. Factors associated with the diagnosis of COVID-19 through a Chi-square bivariate analysis.

Table 3 shows a bivariate regression analysis, identifying a significantly higher prevalence of COVID-19 among patients under 18 years and in cohabitant pregnant women.

Table 3. Factors independently bassociated with the diagnosis of COVID-19 in multiple regression analysis with a generalized linear model (GLM).

In multiple regression analysis, cohabiting marital status was associated with a higher incidence of COVID-19 cases (prevalence ratio: 0.41; 95% confidence interval: 0.24 to 0.71), the only variable that independently linked COVID-19 with the pregnant women.

Discussion

Summary of main findings

The findings of this study show that pregnant women in a hospital in Lima with a diagnosis of COVID-19 had cohabiting marital status as an associated factor.

Many studies have evaluated pregnant women with COVID-19 who presented in labor or near term. Of these, very few cases have been reported before 36 weeks of gestation. No studies have directly examined the association between COVID-19 and early pregnancy [20],[21],[22]. The gestational age was similar to other studies, ranging from 30 to 42 weeks and a median of 36 weeks at the time of evaluation for COVID-19. Zhang et al. report that having COVID-19 during the first weeks of gestation is no more severe than among women who are not pregnant [23].

A systematic review identified preexisting comorbidities, increased maternal age, and elevated body mass index as risk factors for severe COVID-19 in pregnant women [21]. The database used for our study does not include the comorbidities, but it includes maternal age, hemoglobin level, and body mass index. However, after statistical analysis, these variables were not associated with the presence of COVID-19. The same systematic review describes that preterm birth rates are significantly higher in pregnant women with COVID-19 than in pregnant women without the disease [21]. Our study did not assess birth outcomes, as emergency care did not necessarily imply these when assessing the presence of COVID-19.

A study from the United Kingdom describes that of the COVID-19 positive pregnant women admitted to the hospital, 69% were overweight or obese, and 41% were older than 35 years [22]. In our study in Peru, 48% were overweight and obese, and only 13.5% had maternal age over 35 years, so our findings were much lower than those of the United Kingdom. In Spain, the median maternal age of COVID-19 positive pregnant women was 34.6 years [24]. However, a study in Kuwait with positive pregnant women had a median age of 31 years and a mean gestational age of 29 weeks [25].

A retrospective study in Chicago (United States) compared sociodemographic and clinical characteristics in pregnant women with and without coronavirus. The group that resulted positive for COVID-19 was younger, with higher BMI, a higher prevalence of African Americans and Latinos, and children (p < 0.05). Another sociodemographic variable was being single [26]. We believe that having identified cohabiting marital status as a variable associated with COVID-19 in pregnant women is related to the Chicago study since cohabiting is the opposite of being single, hence, its protective role. This finding provides knowledge about risk factors. However, it is necessary to understand why cohabitation (as opposed to being married or single) decreases the risk of having COVID-19. Therefore, it is necessary to develop studies with more representative samples of the pregnant and general populations, assuming that there may be variables behind marital status, such as economic, living environment [27], or cultural variables, among others.

The main limitation of our study lies in the retrospective design, obtaining data from secondary sources such as the clinical history, emergency record book, and prenatal control cards. However, although our clinical data recording did not contemplate research purposes (affecting in this way the rigor and standardization of data collection), the biological vulnerability of pregnancy tends to produce a greater predisposition for care in the health personnel, the pregnant woman and her family, as well as a better information recall needed from the pregnant woman.

Conclusions

Pregnant women with cohabiting marital status have a lower risk of becoming ill with COVID-19. This protective factor does not dismiss the early need to monitor and identify pregnant women to provide timely health care in the event of probable COVID-19 infection.

We believe that further studies are needed to explore the sociodemographic factors behind the cohabiting marital status variable. Further studies in pregnant women are also needed to understand other possible associated factors.

Pregnant women may face a higher risk of infection due to the adaptation and immunosuppressive state of pregnancy. Coping with SARS-CoV-2 may place women and their children at risk.

Notes

Contributor roles
YR, PC, ML: conceptualization, methodology, PC: formal analysis, data curation, ML PC: analysis, writing, revision, editing, visualization, YR, PC, ML: approved the final version and accepted responsibility for the content of the manuscript.

Competing interests
The authors declare that they have no conflicts of interest.

Language of submission
English

Ethics
The study was approved in February 2021 by the Ethics Committee of the Norbert Wiener University, Exp. No. 396-2021.

Data availability statement
The database can be made available on request.