Pregnancy-related hypertensive diseases, such as superimposed preeclampsia, persistent hypertension, preeclampsia, and gestational hypertension, significantly contribute to severe maternal and fetal complications, long-term health issues, and increased mortality rates globally. It is estimated that approximately 10% of pregnancies worldwide are affected by these conditions, posing a substantial public health challenge [1]. These disorders are categorized based on the history and timing of maternal blood pressure elevations, with chronic hypertension identified before the 20th week and gestational hypertension diagnosed thereafter. Preeclampsia is marked by organ damage, primarily to the liver and kidneys, and it is categorized as superimposed preeclampsia in women who already have hypertension.

[2, 3]. Meanwhile, it is acknowledged that vitamin D deficiency is a widespread problem, affecting 18% to 84% of the population globally, influenced by geographic location, ethnicity, cultural dress norms, and diet [4-6]. Hypertension is the most commonly encountered health issue during pregnancy, affecting 5-10% of all pregnancies. The active form of vitamin D, calcitriol, affects genes essential for placental function and fetal development, cytokine synthesis, macrophage activity, and vascular smooth muscle cell proliferation [7, 8]. Thus, it is likely that vitamin D levels affect the development of preeclampsia and gestational hypertension. [9]. Changes during pregnancy alter the metabolism of maternal Vitamin D, increasing levels of Vitamin D binding protein and its active metabolite. However, there have been conflicting findings in research linking vitamin D level to pregnancy outcomes such low birth weight, premature labor, preeclampsia, and caesarean sections [10, 11]. The primary goal of this study is to investigate the relationship between pregnancy outcomes in women with hypertensive problems and their vitamin D levels at the time of childbirth.

The present observational and prospective study was conducted at the Obstetrics and Gynaecology Department at Dr. D. Y. Patil Medical College Hospital and Research Institute, Kolhapur from January 2023 to June 2024 after institutional ethics committee approval. A total of 140 patients satisfying below inclusion and exclusion criteria were involved in the study. Written informed valid consent was taken from patients. Inclusion criteria: Pregnant women, willing to participate in the study, Patients with hypertensive disorders in pregnancy coming for admission because of either delivery or termination of pregnancy at Dr. D. Y. Patil Medical College Hospital and Research Institute, Kolhapur. Exclusion criteria: Received Treatment for vitamin D deficiency after First Trimester., pre-existing or known cases of medical disorders like parathyroidism, malignancies, Renal and Liver disorders.

METHODOLOGY: Patients who were admitted for spontaneous labour or termination with hypertensive disorders before the initiation of the study. A serum vitamin D sample was sent at the time of admission at Dr. D. Y. Patil Medical College Hospital and Research Institute, Kolhapur.

Maternal outcomes like anaemia, PPH, Duration of Labour, Eclampsia, DIC, and Thromboembolism were observed. Neonatal outcomes like low birth weight, neonatal tetany, hyperbilirubinemia, large fontanelle, enamel defects, congenital rickets, and infantile rickets were observed. Specimens for vitamin D analysis should be fresh. Blood serum specimens were collected by using regular red-top vacutainers. 

The enzyme-linked immunosorbent assay used in the Qualisa0TM* 25-OH Vitamin D Quantitative0Test Kit is sandwich-based procedure.  Placed 10 µl of the appropriate microwell's calibrators, controls, and samples.

 The table on neonatal deaths shows that the majority of cases with no neonatal deaths had adequate vitamin D levels, with 101 (99.02%) being sufficient and 23 (95.83%) being insufficient. Deficient levels were also associated with no neonatal deaths, accounting for 11 (100%) of the cases. Only a small fraction of insufficient and sufficient vitamin D levels were associated with neonatal deaths, with 1 (4.17%) and 1 (0.98%) respectively, and no deaths were observed in the deficient and toxicity categories. The P value of 0.65 suggests no significant association between vitamin D levels and neonatal deaths.

  In this table, among 140 evaluated cases, 36 neonates were born with low birth weight. The distribution of vitamin D levels among these cases shows that 52.78% had "Sufficient" levels, 27.78% were "Insufficient", 16.67% were "Deficient", and only 2.78% fell into the "Toxicity" category. The remaining 104 neonates without LBW primarily had "Sufficient" vitamin D levels (79.81%). The statistical analysis provided a p-value of 0.02, indicating a significant association between vitamin D levels and the incidence of LBW.

Table 3: Pre-eclampsia

  Pre-eclampsia examines the same nutritional statuses in patients diagnosed with pre-eclampsia, where 95 (67.86%) of the cases are noted under 'Yes'. It highlights that 72 (75.79%) of the individuals had sufficient nutritional status, which is notably higher compared to those with no pre-eclampsia. This table reports a p-value of 0.4, indicating that the association between nutritional status and pre-eclampsia might not be statistically significant.

Table 4: Preterm Delivery

For preterm deliveries, most cases without preterm delivery had sufficient vitamin D levels, with 97 (95.10%) being sufficient and 22 (91.67%) being insufficient. Among the preterm delivery cases, 5 (4.90%) had sufficient and 2 (8.33%) had insufficient vitamin D levels. Deficient levels showed 10 (90.91%) not associated with preterm delivery and 1 (9.09%) with preterm delivery. No preterm deliveries were observed in the toxicity category. The P value of 0.84 suggests no significant association between vitamin D levels and preterm deliveries.

Table 5: Chronic Hypertension.

  In above table chronic Hypertension, the majority of cases with no chronic hypertension had sufficient vitamin D levels, with 99 (97.06%) being sufficient and 23 (95.83%) being insufficient. A smaller percentage of cases with chronic hypertension had sufficient levels, with 3 (2.94%) sufficient and 1 (4.17%) insufficient. Deficient levels showed 10 (90.91%) not associated with chronic hypertension and 1 (9.09%) associated with chronic hypertension. The toxicity category showed 2 (66.67%) not associated with chronic hypertension and 1 (33.33%) with chronic hypertension. The P value of 0.06 suggests a potential association between vitamin D levels and chronic hypertension, but it is not statistically significant.

Table 6: Mode of delivery

   For mode of delivery, most cases of FTVD (Full Term Vaginal Delivery) had sufficient (30.39%) or insufficient (25%) vitamin D levels, while LSCS (Lower Segment Caesarean Section) had higher percentages in deficient (81.82%) and insufficient (66.67%) categories. PTVD (Pre Term Vaginal Delivery) was rare, with only a few cases in the insufficient (8.33%) and sufficient (0.98%) categories. The P value of 0.4 indicates no significant association between vitamin D levels and mode of delivery.

 The data on IUGR (Intrauterine Growth Restriction) show that most cases without IUGR had high percentages in the deficient (100%), insufficient (91.67%), and sufficient (99.02%) categories. Cases with IUGR were fewer, with only 8.33% in the insufficient and 0.98% in the sufficient categories. The IUGR and vitamin D levels do not appear to be significantly correlated, as indicated by the P value of 0.14. 

 For placental insufficiency, the majority of cases without insufficiency had high percentages across all vitamin D levels, with 100% in the deficient, sufficient, and toxicity categories and 91.67% in the insufficient category. Cases with insufficiency were fewer, with only 8.33% in the insufficient category. The P value of 0.02 indicates a significant association between vitamin D levels and placental insufficiency.

The p - value of 0.65 suggests that there is no statistically significant link between neonatal mortality and vitamin D levels in the study group.

Comparing these findings with other studies reveals variations. A study conducted by Genuis SJ et al. 2015 revealed that decreased levels of vitamin D were significantly linked to negative outcomes during pregnancy, such as premature birth and preeclampsia, which could indirectly impact the survival of newborns. Our data on the toxicity group is currently insufficient, and additional data is necessary for proper analysis and alignment.

The statistical analysis provided a p - value of 0.02, indicating a significant association between vitamin Levels and incidence of LBW.

This data suggests a trend where lower vitamin D levels might be associated with higher rates of LBW.  a study by Thorne-Lyman A et al. (2012) [12]. Found a positive correlation between sufficient Vitamin D levels and optimal birth weights, suggesting that adequate Vitamin D is critical for fetal growth, which aligns with our finding.

Conversely, Wagner CL et al. (2013) [13]. Reported that both deficient and insufficient Vitamin D levels were associated with an increased risk of low birth weight, which is consistent with our findings.  

Overall, 67.86% of the study population had pre-eclampsia, with a p-value of 0.4 indicating no significant difference in pre-eclampsia rates among the nutrient categories.

These findings are consistent with other studies examining the relationship between Vitamin D levels and pre-eclampsia.  A recent research conducted by Kinshella MW and colleagues (2022) found a correlation between adequate Vitamin D levels and an increased risk of developing preeclampsia. which aligns with our finding.  

Overall, 5.71% of the study population had preterm deliveries, and the p-value of 0.84 indicates no significant difference in preterm delivery rates among the nutrient categories.

Comparing these findings with other studies, we see both consistencies and variances. A study by Zhang Y et al. (20119) [14]. Reported that deficient Vitamin D levels had higher preterm delivery rates, which is not consistent with our findings. Maternal et al. (2018) [15], found no significant increase in preterm deliveries among vitamin D toxicity group, 

Overall, 4.29% of the study population had a history of chronic hypertension, with a p-value of

0.06, indicating a trend towards significance in chronic hypertension rates among the categories.

These findings can be compared with other studies that explore the relationship between Vitamin D levels and the occurrence of chronic hypertension. Garovic VD et al. (2023) [16]. Reported.that sufficient Vitamin D levels were.associated with a lower incidence of chronic hypertension, which aligns with our finding. Conversely, a study by Hao H et al. (2021) [17]. Found that vitamin D deficiencies were linked to a higher risk of chronic hypertension. 

Overall, the p-value of 0.4 indicates no significant difference in the mode of delivery among the different nutrient categories.

Comparing these findings with other studies reveals both consistencies and variations.  Betran AP et al. (2021) [18]. Reported that sufficient Vitamin D.levels were associated with a higher incidence of FTVD, which is not consistent with our finding. Conversely, Gernand AD et al. (2016) [19]. Found that vitamin D deficiencies were linked to a higher rate of LSCS, similar to our findings. In our study, among patients who underwent normal delivery, 72% had sufficient vitamin D levels, compared to 77% of sufficient vitamin D levels in patients who underwent LSCS. This suggests that the mode of delivery is not significantly related to vitamin D levels.

Overall, 7.86% of the study population received Vitamin D supplements, and the p-value of 0.21 indicates no significant difference in supplementation rates among the nutrient categories. Comparing these findings with other studies highlights the role of Vitamin D supplementation in various nutrient groups.  a study by Arya S etal. (2022) [20]. Found that Vitamin D supplementation was more common in populations with sufficient Vitamin D levels, consistent with our finding. The reasoning behind this is likely because of the attention and monitoring of sufficient Vitamin D levels in individuals who are already undergoing healthcare interventions. Conversely, Sharma D et al. (2016) [21]. Reported that populations with deficient and insufficient Vitamin D levels were less likely to receive Vitamin D supplements, which aligns with our findings. 

Overall, 2.14% of the study population had IUGR, with a p-value of 0.14 indicating no significant difference in IUGR rates among the vitamin D categories.

When comparing these findings with other studies, we find both consistencies and discrepancies. In a study by Brett KE, et al. (2014) [22]. The link between adequate Vitamin D levels and reduced incidence of IUGR has been reported. which aligns with our finding of 0.98% in the sufficient category. Conversely, Tain YL et al. (2023) [23]. Found that vitamin D deficiencies were linked to a higher risk of IUGR, not similar to our observation. 

1.43% of the study population had placental insufficiency, with a p-value of 0.02 indicating a significant difference in placental insufficiency rates among the nutrient categories.

These findings are consistent with several studies that examine the relationship between Vitamin

D levels and placental health.  Nelms CL et al. (2021) [24]. Reported that adequate levels of Vitamin D were linked to a decreased occurrence of placental insufficiency, which aligns with our finding. Conversely, Arshad R et al. (2022) [25]. Found that vitamin D insufficiency was linked to a higher risk of placental insufficiency, similar to our observation. 

The occurrence of stillbirth across different Vitamin D level categories, with no cases of stillbirth reported among the 140 participants. Specifically, 100% of participants in each category— deficient, insufficient, sufficient, and toxicity—did not experience stillbirth. This uniform absence of stillbirth across all Vitamin D levels suggests that within this study population, Vitamin D levels did not impact the occurrence of stillbirth.

Comparing these findings with other studies, we observe both consistencies and contrasts.  A study by Scholl TO et al. (2012) [26]. Reported a higher incidence of stillbirth in populations with vitamin D deficiencies. Palacios C et al. (2019) [27]. Revealed that maintaining adequate Vitamin D levels was generally linked to a reduced occurrence of stillbirth. The overall uniform absence of stillbirth in our study population might indicate effective prenatal care and management of Vitamin D levels or could be attributed to the specific characteristics and size of the population studied.

The occurrence of congenital malformations across different Vitamin D level categories, with none of the participants experiencing congenital malformations. Specifically, 100% of participants in each category deficient, insufficient, sufficient, and toxicity—did not have congenital malformations. This indicates a uniform absence of congenital malformations across all Vitamin

D levels in this study. These findings contrast with several studies that have explored the relationship between Vitamin D levels and congenital malformations.  a study by McNally JD et al. (2013) [28]. Reported a higher incidence of congenital malformations in populations with vitamin D deficiencies, implying that a vitamin D deficit may increase the chance of congenital abnormalities. In our study sample may be a result of good prenatal care and nutrition administration, or it may be a result of the particular traits of the community under investigation.

The study underscores the importance of holistic management of hypertensive disorders in pregnancy, focusing on established risk factors and comprehensive prenatal care. While maintaining adequate vitamin D levels is important for overall health, universal screening and supplementation for vitamin D may not be necessary unless specific deficiencies are identified. Future research should explore the complex interactions between vitamin D, various medical conditions, medications, and pregnancy outcomes. Longitudinal studies and larger, more diverse cohorts are essential to validate these findings and to provide a deeper understanding of the role of vitamin D in maternal-fetal health. In the end, this study adds to the expanding corpus of research on vitamin D's role during pregnancy and emphasizes the necessity of ongoing studies and evidence-based treatment procedures to maximize the health of both the mother and the fetus. 

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