Prevalence of Pregnancy-Induced Hypertension and Its High-Risk Factors among the Antenatal Women

Introduction

Pregnancy is a physiological phenomenon for most women. Sometimes pregnancy won’t be normal due to various reasons or risk factors. Mothers need to take care of their health during pregnancy to continue healthy pregnancy. Due to physiological changes, there are many health issues women undergo during pregnancy. Pregnancy-induced hypertension (PIH) is one of the most leading issue and the cause of maternal and fetus mortality.¹ PIH is clinically defined as new onset of hypertension (HTN), that is, systolic blood pressure (BP) ≥140 mm Hg and/or diastolic BP ≥90 mm Hg or an absolute rise of BP of at least 140/90 mm Hg, if the previous BP is not known or a rise in systolic pressure of at least 30 mm Hg or a rise in diastolic pressure of at least 15 mm Hg over the previously known BP, at ≥20 weeks of gestation in the absence of proteinuria.²

The incidence of PIH ranges from 5 to 15% in the different regions of India.³ Worldwide 10% of all pregnancies are complicated by PIH.⁴ In India, according to a 2017 survey, 8 to 10% of pregnancies are complicated with PIH. In Karnataka, 4 to 5/1000 are affected.⁵ The main risk factors of PIH are family history, placental abnormalities, obesity (body mass index >30), previous history of HTN, hormonal imbalance, maternal age, primigravida, and preexisting vascular disease.⁶

To diagnose PIH, especially when the pregnant woman is seen for the first time after 20 weeks of gestation, or when there is no record of BP measurement before 20 weeks of pregnancy, is not always easy. However, the criteria that facilitate the diagnosis of PIH and its differentiation from other hypertensive disorders of pregnancy include elevated BP, which was previously normal, absence of protein in the urine, and absence of manifestation of preeclampsia–eclampsia. Furthermore, in the differential diagnosis, spot urine polymerase chain reaction; full blood count; urea, creatinine, electrolytes; ultrasound assessment of fetal growth and amniotic fluid volume; and umbilical artery Doppler assessment are generally included in the battery of test that needs to be done.⁷ The main complications of PIH are preeclampsia, eclampsia, antepartum hemorrhage, postpartum hemorrhage, and fetal death or maternal death. Hence, the present study was conducted to find out the prevalence of PIH and risk factors among the antenatal woman.

Methods

A descriptive survey approach design was used to assess the prevalence of PIH and its high-risk factors among antenatal women. Mothers attending obstetrics and gynecology outpatient department (OBG OPD) of the selected tertiary hospital at Mangaluru were included as the study population. A total of 400 antenatal mothers were purposively selected as participants for the study. Among them, the diagnosis of PIH was confirmed by reviewing their case records for the diagnosis made by the obstetrician.

Results

The analysis and interpretation of the data are organized and presented under the following headings.

Table 1 depicts that 196 (49%) antenatal mothers belong to the 20 to 25 age group and only 9 (2.25%) mothers were belonging to the 36 to 40 age group. The education status of the mothers shows that 170 (4.5%) were completed only primary education. The majority of the mothers were housewives. A total of 256 mothers were multigravida. The gestational age of the mothers shows 186 were in the 13 to 29 weeks of gestation.

Risk Factors of PIH (Table 2)

Table 2 Frequency and percentage distribution of risk factors related to obstetric conditions among PIH mothers (n = 43)

S. no.	Variables	F	(%)
1	Previous history of gestational hypertension
	a) Present	10	23
	b) Absent	33	76.74
2	History of GDM
	a) Present	7	16
	b) Absent	36	83.72
3	History of abortion
	a) Present	1	2.32
	b) Absent	42	97.67
4	Polycystic ovarian disease	0	0
5	Preterm labor	0	0
6	Multiple pregnancy	0	0

Abbreviations: GDM, gestational diabetes; PIH, pregnancy-induced hypertension.

Among the 43 antenatal, 10 (23%) had a previous history of PIH and 7 (16%) of them had gestational diabetes and 1(10.025%) had a previous history of abortion.

Fig. 1 depicts that among 43 antenatal women, 34.88% had a family history of HTN, and 21% had a history of thyroid problems (Table 3).

Table 3 Adjusted risk factors of PIH

S. no.	Exposed factors	OR	95% CI
1.	Do you eat often fatty food such as fried chicken, salty snacks, potato chips regularly?	0.271	0.035–2.105
2.	Family history of hypertension	1.930	1.130–3.296
3.	Previous history of PIH	1.276	0.125–11.836
4.	History of renal disease	0.941	0.474–1.868
5.	History of diabetics mellitus	0.992	0.455–2.161
6.	History of thyroid problems	1.904	0.786–4.611
7.	History of cardiac illness	0783	0.744–0.825
8.	History of migraine	1.467	0.280–7.694
9.	History of abortion	0.605	0.227–1.612
10.	Use of oral contraceptive medication before pregnancy	0.782	0.743–0.824
11.	History of rheumatoid arthritis	0.909	0.100–8.238
12.	Multiple pregnancy	0.782	0.742–0.824

Abbreviations: CI, confidence interval; OR, odds ratio; PIH, pregnancy-induced hypertension.

Close

Fig. 1 Distribution of risk factors related to medical and family history among pregnancy-induced hypertension (PIH) mothers. HTN, hypertension.

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The most important risk factors found for PIH in the present study are the previous history of PIH (adjusted odds ratio [AOR] =1.276, 95% confidence interval [CI]: 0.125–11.836), family history of HTN (AOR=1.930,95% CI: 1.130–3.296), and thyroid problems (AOR=1.904, CI: 0.786–4.611).

Discussion

In this study, the prevalence of PIH among antenatal women was 10.75%. Similar findings are seen in the study conducted in Brazil and South Africa where the prevalence of PIH shows 13.9 and 12%, respectively. The difference may be due to the differences in the study period, sample size, geographical difference of the study areas, and health-seeking behavior of the pregnant women in the area.⁸

The most important risk factors found for PIH in the present study are the previous history of PIH, family history, thyroid problems, and abortion. A similar cross-sectional study was conducted on PIH and associated factors among pregnant women in 2015 in Ethiopia. Results showed maternal education (AOR = 2.5, 95% CI% = 1.2–5.3), age (AOR = 2.73, 95% CI = 1.31–5.7), previous history of preeclampsia (AOR = 19.3, 95% CI = 5.2–72.1), and family history of preeclampsia (AOR = 7.2, 95% CI = 2.9–17.8) were identified as predictor factors for the occurrence of PIH.⁹ The study conducted by Tehrani et al shows that among 801 women, 534 (66.7%) had a normal delivery and 267 cases had an abnormal delivery outcome that included 60 (7.5%) abortion, 40 (5%) ectopic pregnancy, and 167 (20.8%) preterm labor.¹⁰

The most important risk factors found for PIH in the present study are the previous history of PIH (AOR=1.276, 95% CI: 0.125–11.836), family history of HTN (AOR=1.930,95% CI: 1.130–3.296), and thyroid problems (AOR=1.904, CI: 0.786–4.611). A similar case–control study was conducted on risk factors associated with PIH among 216 pregnant women attending antenatal care clinic at the Hohoe Municipal Hospital 2017. They found advanced maternal age of 35 to 39 years, consumption of transfatty food, a family history of HTN, and history of previous preterm delivery to be significantly associated with PIH (AOR = 3.53, p = 0.048), (AOR = 4.43, p < 0.001), (AOR = 3.42, p = 0.012) and (AOR = 5.14, p = 0.017), respectively.⁷

Conclusion

The prevalence of PIH is quite high in the present study. Women with PIH are at higher risk of adverse pregnancy outcomes. The most important risk factors found for PIH in the present study are the previous history of PIH, family history, thyroid problems, and abortion. Poor knowledge of the management of PIH and inadequate resources are a threat to the proper management of PIH.

Limitations

The main limitation of the present study is that it did not assess the risk factors among normal antenatal mothers. In this study, risk factors are assessed only in diagnosed PIH mothers by the obstetrician.