Hypertensive disorders of pregnancy are a mysterious and clinically complex category of pregnancy problems that account for a significant burden of disease in both industrialized and less industrialized nations [1]. According to a meta-analysis by the WHO in June 2014, hypertensive disorders of pregnancy account for 14% of all maternal deaths [2]. The incidence of pregnancy-induced hypertension (PIH) ranges from 5% to 15% in India [3].

Hypertensive disorders of pregnancy include chronic hypertension, gestational hypertension, preeclampsia, chronic hypertension with superimposed preeclampsia, and eclampsia. Pregnancy-induced hypertension (PIH) includes both gestational hypertension and preeclampsia.

Human chorionic gonadotropin (HCG) is a glycoprotein composed of two non-covalently linked subunits, \(\alpha\) and \(\beta\), and is produced during pregnancy by the developing embryo and later by the syncytiotrophoblast of the placenta. Its plasma half-life is 36 hours. High beta-HCG production in early second trimester when definitive placental development occurs may be used as a predictive marker as the placenta is the known primary trigger of gestational hypertension/preeclampsia [2]. In pre-eclampsia, the rise in blood pressure is due to vasoconstriction and impaired angiogenesis, leading to hypoxia and hyperplasia of trophoblastic cells, which causes hypersecretion of placental hormones, ultimately leading to high levels of circulating beta-HCG.

The aim of this study is to estimate Serum \(\beta\)-HCG in early second trimester as a predictor of pregnancy-induced hypertension.

A cross-sectional study was conducted among pregnant females who were in their second trimester and attending the OPD clinic in the Department of Obstetrics and Gynaecology, JK Hospital, LNMC & RC, Bhopal, from January 2019 to June 2020. Women with singleton pregnancy visiting Obs and Gynae OPD/IPD of the hospital during their second trimester (13-20 weeks) of pregnancy were enrolled in the study. The study design was a prospective observational study, and the sample size was 150. A 5 ml of venous blood sample was collected, and tests were carried out. Estimation of serum beta HCG level was done by enzyme-linked fluorescence immunoassay.

Inclusion Criteria

All pregnant women in their second trimester (13 - 20 weeks) aged above 18 years and below 40 years, with informed consent, and having confirmed singleton pregnancy by Ultrasonography were included. Additionally, they should have been previously normotensive and non-proteinuric.

Exclusion Criteria

All pregnant women aged less than 18 and more than 40 years, with multiple pregnancies, episodes of Chronic Hypertension, Gestational Trophoblastic Diseases in the present or previous pregnancy, Down syndrome or any congenital anomalies, and pregnancies associated with Germ cell tumors were excluded.

After data collection, it was entered in an Excel worksheet. All data analysis was done with the help of EpiInfo software version 7. The continuous quantitative data were summarized as mean and standard deviation, while discrete (categorical) data in numbers and percentage (%). The categorical variables were compared by chi-square (\(\chi^{2}\)) test. A p-value < 0.05 was considered as significant and the value < 0.001 was considered highly significant.

It was observed that the maximum number of pregnant women were in the 26-30 years age group, accounting for 52% of the total, followed by the 21-25 years age group, as seen in Table 1. The mean age of women in the pregnancy-induced hypertension group was \(26.13 \pm 3.4079\) years and in the normotensive group, it was \(25.1875 \pm 2.9726\) years. As the age advances, the incidence of pregnancy-induced hypertension increases (Table 1).

It was observed that the maximum number were of Primigravida, 39.3%, closely followed by Gravida-2 (38.7%), followed by Gravida-3 group (15.3%), and more than Gravida-4 group (17.5%) as seen in Table 2.

On observing the patients with respect to the period of gestation in weeks completed, it was observed that the maximum number were at 17-18 weeks of gestation (45.3%), followed by 13-16 weeks gestation (28%), and then 19-20 weeks gestation (26.7%), as shown in Table 3.

On observing the patients with respect to beta HCG levels, it was observed that 62 (i.e., 41.3%) had beta HCG levels above 25000, and 88 (i.e., 58.7%) had Beta HCG levels below 25000, as seen in Table 4.

Hypertensive disorders of pregnancy are one of the most common complications of pregnancy and affect up to 8% of all gestations [4]. The exact mechanism of pregnancy-induced hypertension is unknown, and no standards for prediction exist, making the management of pregnancy-induced hypertension challenging and controversial. The present study was conducted to analyze the relationship between maternal serum beta-hCG levels during the second trimester and the subsequent development of hypertension. Our study also analyzed the association of high levels of beta hCG with the severity of hypertensive disorders in pregnancy.

Most of the patients in our study were in the age group of 21-30 years, i.e., 113 (75.3%), which is the peak reproductive age group in our country. Our results are consistent with findings from studies done by various authors in which no significant association between age and hypertensive disorders of pregnancy was observed.

In our study, among 58 cases of PIH, 20 cases were primigravida, and similarly, 20 cases belonged to gravida 2 group. No statistical significance was found between parity and PIH. Kaur et al. [5], in their study, found no significant association between parity and PIH, but the occurrence of PIH was more common among primiparas. In our study, Serum beta-hCG as a predictor of PIH had a sensitivity of 67.2% and specificity of 75%. In other studies with second-trimester maternal serum beta-hCG values for predicting hypertensive disorders of pregnancy, like the study by Kaur et al. [5], a sensitivity of 90.91% and specificity of 97.44% were reported.

The frequency of pregnancy-induced hypertension at a tertiary care center in our study was found to be 38.6%. The frequency in our study is higher than in studies done by Vidyabati et al. [6] (17.68%), Singh et al. [7] (21.48%), Yadav et al. [8] (17.5%), and Wander et al. [9] (23.636%).

The small sample size for this study necessitates the need for further large-scale studies considering the importance of beta-hCG in PIH prediction.

Pregnancy-induced hypertension is still a little understood entity, despite the enormous impact of its complications on maternal and fetal outcomes. The above study concludes that the frequency of pregnancy-induced hypertension at a tertiary care hospital is 38.6%. Maternal and perinatal morbidity are directly related to the diagnosis and management of pregnancy-induced hypertension. Serum beta-hCG should be considered during risk-based counseling. 13-18 weeks of pregnancy are good non-invasive predictors of hypertensive disorders of pregnancy. Therefore, women with raised beta-hCG should be carefully followed up for hypertension so that these women can be referred to a tertiary care center for better treatment.

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