1. Background and Rationale

Hypertensive disorders of pregnancy (HDP) are a major cause of maternal and birth-related morbidity in every country of the world. These include preeclampsia, eclampsia, and gestational hypertension, which are the key subtypes. The World Health Organization estimates that HDP occur in 5–10 percent of pregnancies worldwide (Tang et al. 2025). Clinicians acknowledge that HDP is one of the causes of avoidable maternal deaths.

 

The retinal vasculature provides a distinctive view of observing microvascular changes firsthand. Retinal examination is a non-invasive method of vascular damage assessment used by ophthalmologists in the past. Vasospasm and endothelial dysfunction mediate typical retinal changes in HDP. These alterations consist of arterial constriction, arteriovenous crossing changes, and retinal hemorrhages. Papilledema and cotton wool spots are found in more severe manifestations of the disease.

 

These findings are graded by clinicians with the help of the Keith–Wagener–Barker classification system (Matsuoka et al. 2022). The classification has been effective in correlating retinal findings with the severity of systemic disease. Various researchers have shown that retinal vascular alterations indicate the severity of preeclampsia. These findings are also proposed by researchers to reflect underlying placental vascular pathology.

 

There is, however, mixed evidence on their predictive ability for fetomaternal outcomes. There is no agreement currently as to the clinical utility of their prognosis (Graupner et al. 2025). It therefore becomes vital to conduct a systematic, evidence-based study of retinal changes in HDP. This type of analysis may provide better insights into disease severity and prognosis.

 

2. Aim

To evaluate retinal alterations in patients with hypertensive disorders of pregnancy and determine their association with disease severity and fetomaternal outcomes.

 

3. Objectives

Primary Objective

• To assess the prevalence and pattern of retinal changes in patients with hypertensive disorders of pregnancy.

Secondary Objectives

1. To correlate retinal changes with severity of hypertensive disorders of pregnancy.

2. To evaluate the association between retinal findings and maternal complications.

3. To assess the relationship between retinal alterations and fetal outcomes such as:

·       Preterm birth

·       Low birth weight

·       Intrauterine growth restriction

·       Perinatal mortality

4. Study Design

This study was a prospective observational design. We were keen on recruiting and tracking eligible respondents over time. We documented clinical, ophthalmological, and obstetric records without interfering in the control of patients. This model was appropriate to represent the disease course and outcome trends in reality. It enabled us to develop significant associations between retinal changes and fetomaternal outcomes in hypertensive pregnancy disease.

5. Study Setting

This study was performed in the Department of Obstetrics and Gynecology, Government Medical College, Nagpur. The department handles a large number of antenatal and obstetric cases per annum. The Department of Ophthalmology was actively involved in collaborating to conduct standardized fundoscopic examinations. This coordination across the department was able to secure full clinical and ophthalmological assessments of every registered candidate. Government Medical College, Nagpur is a large tertiary referral facility, which offers a representative and diverse population for the study.

 

6. Study Duration

 

7. Study Population

The target population in this study were pregnant women who had hypertensive disorders of pregnancy. We enrolled the two key sources of participants in the institution. The antenatal clinic had access to outpatient cases who attended follow-up of pregnancy. The obstetric units were contributory to the patients who were admitted and are in need of inpatient care. This dual approach of recruitment was used to help have sufficient representation of mild and severe cases of hypertensive disorder and therefore added more validity to the entire study.

8. Sample Size

Using prevalence of retinal changes in HDP estimated at 30–40% from previous studies:

Sample size calculation formula:

n=Z2×p(1−p)d2n = \frac{Z^2 \times p (1-p)}{d^2}n=d2Z2×p(1−p)

Where:

• Z=1.96Z = 1.96Z=1.96 (95% confidence level)

• p=0.35p = 0.35p=0.35 (expected prevalence)

• d=0.07d = 0.07d=0.07 (precision)

Estimated sample size ≈ 180 participants

Final sample size (including 10% attrition): 200 patients

 

The sample size was calculated using the prevalence of retinal changes in pregnancy hypertensive disorders estimated. This prevalence can be found in previous literature, and it is between 30 and 40%. The value of 35% was used by us as a predicted prevalence. This process was done using the standard sample size formula of prevalence studies.

Researchers applied the formula: n = Z² × p(1−p) / d²

The number 1.96 in this formula denotes the level of confidence value of 1.96 which is used to define the confidence interval of 95%. The prevalence value (p) is expected to be 0.35, which is based on the results of the previous literature. We established the level of precision (d) to be 0.07 which is a reasonable level of error. When these values are substituted into the formula the estimated minimum sample size came about 180 people.

Nonetheless, we admit that prospective observational studies are generally affected by participant dropout and loss to follow-up. Thus, we included an attrition buffer of 10 percent to the minimum sample size. This is an addition that considers the possibility of withdrawn participants, incomplete data, or failure to accomplish follow-up assessments. The inclusion of this buffer increases the overall sample size required to 200 patients. The final sample size is sufficient to guarantee adequate statistical power and uphold study validity during the entire recruitment and follow-up period.

 

9. Inclusion Criteria

• Pregnant women ≥20 weeks gestation

• Diagnosed with hypertensive disorder of pregnancy according to American College of Obstetricians and Gynecologists criteria

• Singleton pregnancy

• Consent to participate

10. Exclusion Criteria

• Pre-existing chronic hypertension

• Diabetes mellitus with retinopathy

• Known ocular disease affecting retina

• Severe systemic disease unrelated to HDP

• Multiple pregnancy

11. Study Variables

Independent Variables

• Maternal age

• Parity

• Gestational age

• Type of hypertensive disorder

• Blood pressure levels

• Laboratory parameters (platelet count, liver enzymes, serum creatinine)

 

Dependent Variables

Retinal findings

• Arteriolar narrowing

• AV nicking

• Hemorrhages

• Exudates

• Papilledema

 

Maternal outcomes

• HELLP syndrome

• Placental abruption

• ICU admission

Fetal outcomes

• Birth weight

• Apgar score

• NICU admission

• Perinatal mortality

12. Study Procedure

Step 1: Patient Recruitment and Informed Consent

All pregnant women with hypertensive disorders of pregnancy were identified and screened actively. Each qualified participant was thoroughly informed about the purpose of the study, the procedures and the risks involved. Enrolment of patients was only done in cases where they have written informed consent (Godskesen, Björk & Juth, 2023). This was done in order to make the process voluntary and maintain ethical standards during the study.

Step 2: Clinical and Obstetric History Recording

Detailed clinical and obstetric history was recorded by trained investigators in all the enrolled participants. We recorded maternal age, parity, gestational age, history of past pregnancies, and comorbidities. The nature and duration of the hypertensive disorder were also documented. This overall history constitutes the basis of data for future clinical correlation and statistical analysis.

 

Step 3: Blood Pressure Measurement

Blood pressure was measured to all the participants enrolled in the study according to standard clinical protocols (Konstantinidis et al., 2022). We employed calibrated sphygmomanometers that have the right cuff size to give the correct reading. Measurements were taken in the sitting posture after enough rest by trained staff. The systolic and the diastolic values were systematically recorded. These readings assisted in categorization of the severity of diseases and tracking hypertensive conditions over a period of time.

 

Step 4: Laboratory Investigations

All study participants being enrolled in a study were subjected to essential laboratory investigations. These tests involved serum creatinine, platelet count and liver enzyme levels. The laboratory results were used to evaluate the involvement of end organs and the severity of the disease in every subject. All laboratory values were methodically recorded, documented and compared to retinal results and fetomaternal outcomes later.

 

Step 5: Fundoscopic Examination

Each of the participants registered underwent fundoscopic examination by a qualified ophthalmologist. The examiner initially instilled pupillary dilation drops to attain sufficient mydriasis. The indirect ophthalmoscopy method was used to assess the retinal changes (dos Santos Martins et al., 2022). This study was performed in the Department of Obstetrics and Gynecology, Government Medical College, Nagpur which handles a large number of antenatal and obstetric cases per annum. The Department of Ophthalmology was actively involved in collaborating to conduct standardized fundoscopic examinations. The training across the department was able to secure full clinical and ophthalmological assessments of every registered candidate. Government Medical College, Nagpur is a large tertiary referral facility, which offers a representative and diverse population to study a close and broad field picture of the retinal vessels. The ophthalmologist examined both eyes in detail and made a detailed record of all the findings of the retina. This standardized test was very effective in maintaining uniformity and consistency in all the participants of the study.

 

Step 6: Grading of Retinal Findings

All the identified retinal findings to which the examining ophthalmologist is assigned are graded according to the KeithWagenerBarker classification system (Matsuoka et al., 2022). This is the most common classification where the grades depend on the severity of the changes in the arterioles, hemorrhage, exudates, and papilledema. Standard grading provides objective and reproducible grading plans of all participants. These retinal grades were then compared with clinical disease severity and fetomaternal outcome to give meaningful statistics to the researchers.

13. Outcome Measures

Primary Outcome: Prevalence of Retinal Alterations Among HDP Patients

The main objective of this research is to establish the incidence of retinal changes of hypertensive disorders of pregnancy patients. All the retinal changes found were recorded and measured in an organized systemic fashion by the investigators in all the enrolled participants. This finding determined the rate and trend of retinal involvement in HDP, which forms a baseline data upon which additional clinical correlation and studies was done (Xiong et al., 2025).

 

Secondary Outcome 1: Correlation Between Retinal Grade and Severity of HDP

Active associations between Keith-Wagener-Barker retinal grades and the severity of the clinical hypertensive disorders of pregnancy were being made (Warad et al., 2023). This result establish whether the deterioration of retinal results is associated with escalating levels of disease severity. By creating this relationship, there is a stronger possibility that retinal examination as a non-invasive method is an objective tool to measure the severity of hypertensive disorder in pregnant women.

 

Secondary Outcome 2: Association Between Retinal Changes and Fetomaternal Outcomes

Researchers carefully determined the correlation between the detected retinal changes and fetomaternal outcomes. The outcomes included preterm births, low birth weight, intrauterine growth restriction, HELLP syndrome, placental abruption, and perinatal mortality. The significance of these associations confirms that retinal examination is a valuable prognostic indicator that can be useful in risk stratification and clinical management plans in hypertensive pregnancy.

14. Statistical Analysis

Study Population Overview

In the Panel A, Gestational Hypertension is shown to be the biggest subgroup with an percentage of 40 (n=80) of total population taken part in the research. The proportion of mild Preeclampsia is 35% (n=70), severe Preeclampsia is 20% (n=40), and Eclampsia is 5% (n=10). This distribution represents the occurrence of hypertensive disorders of pregnancy on a natural spectrum. Panel B shows that 33% (n=66) of all patients had the change of the retina. The most common single finding was Arteriolar Narrowing which was found to be 22.5 percent (n=45) then AV Nicking 7.5 percent (n=15). Retinal Hemorrhage, Exudates and Papilledema were less common, indicating the relationship between them and higher levels of disease progression.