Table 2. Overview of the published studies in the review article.

Sr no.	Study ID, year & country	Study design	Aim	Participants	Summary of findings
1	Bibi et al. 2010 [8]	Cohort study	To clarify the connection between blood homocysteine (hcy) levels and vascular-related pregnancy problems in expectant women and to evaluate the impact of folate, vitamin B12, and B6 on decreasing homocysteine levels.	A total of 332 prenatal women were enrolled, of whom 112 had normal, healthy pregnancies; 61 had pre-eclampsia; 49 had eclampsia; and 110 experienced placental abruption	Higher hcy levels have been seen in pregnancies affected by eclampsia and preeclampsia. The theory that folate, vitamin 812, and vitamin B6 reduce hcy levels in hyperhomocysteinemic women is supported by data.
2	Acılmıs et al. 2011 [9]	case-control study	The study intended to assess the connection between preeclampsia severity and to assess maternal and foetal blood levels of homocysteine, vitamin B12, folic acid, and homocysteine level in placental tissue	Pregnant women in 26 cases with mild preeclampsia, 26 cases with severe pre-eclampsia, and 26 cases of normal pregnancies.	Serum homocysteine levels in the mother and foetus were considerably raised in the severe pre-eclampsia group in contrast with the mild pre-eclampsia and control groups, indicating that elevated serum homocysteine levels may be related to the severity of pre-eclampsia. On the contrary, it appears that a lack of folic acid and vitamin B12 was not linked to increased blood homocysteine levels.
3	Mascarenhas et al. 2014 [10]		to review the connection of homocysteine levels in the first trimester (8–12 weeks) and foetal and mother outcomes.	In this cohort study, 100 pregnant women between the ages of 8 and 12 weeks participated.	Raised first trimester Serum homocysteine has been linked to preterm birth, hypertensive disorders of pregnancy, and a history of miscarriages. Pregnancy's low birth weight, oligohydramnios, meconium-stained amniotic fluid, and hypertensive disorders of pregnancy are also linked to this.
4	Wadhwani et al. 2015  [11]	Prospective cohort study	The study compares Hypertensive cases and normotensive control (NC) women in terms of their levels of maternal plasma folate, vitamin B12, and homocysteine from the commencement of pregnancy until delivery.	In the study, there were 62 instances of pre-eclampsia and 126 controls with normal blood pressure.	According to the study's findings, pregnant women with PE had elevated homocysteine levels throughout their whole pregnancy.
5	Maru et al. 2016 [12]	A comparative study	to establish the association between blood homocysteine levels, relevant laboratory tests, and pregnancy-related hypertension disorders.	This prospective study was placed over a period of two years. A total of 214 cases were investigated. They were split into four groups: those with eclampsia (32), moderate preeclampsia (64), and severe preeclampsia (50). And 68 controls.	The statistical bond between homocysteine values and the ferocity of hypertension and complications from hypertensive disorders is clear. It can be used as a genuine prediction marker for hypertension and the broad syndrome that it causes.
6	Mukhopadhyay et al. 2017 [13]	Prospective analysis	To ascertain the relationship between Hyperhomocysteinemia (HHCY) and recurrent miscarriages as well as the effects of folic acid (vitamin B 9), vitamin B 12, and HHCY on lowering its levels in the body and preventing obstetric problems.	A prospective research was conducted, and the blood homocysteine levels of pregnant women who had been admitted to our hospital over a two-year period and had a history of unexplained RPL were measured.	RPL and Hyperhomocysteinemia are related. Homocysteine levels are lowered when those with Hyperhomocysteinemia take vitamin supplements.
7	Gaiday et al. 2018 [14]	Systemic review	The goal of the study was to integrate the many pieces of currently available scientific evidence and fill in any knowledge gaps about Homocysteine levels in pregnancy and its relationship with certain pregnancy problems.	1287 research on Hcy and pregnancy complications looked at various effects and issues that might harm the mother and the foetus.	In review it was concluded that Homocysteine levels vary in an uncomplicated pregnancy. Then, throughout the second and third trimesters, the Hcy level usually decreases. A correlation between polymorphism and abortion has been shown in several research. There is enough evidence to support the link between HHcy and PE. High Hcy levels increased the likelihood of placental abruption by 5.3 times. However, the findings do not support the theory that Hcy levels are correlated with placental abruption.
8	Chaudhry et al. 2020 [5]	Cohort study	The purpose of this study was to find out if a higher level of maternal plasma homocysteine in the early to mid-second trimester is linked to a higher risk of placenta issues.	The cohort study includes 7587 individuals.	Their findings imply that placenta-mediated pregnancy complications are affected independently by early to mid-second trimester maternal homocysteine elevation.
9	Chamotra et al. 2020 [15]	Prospective cohort study	To ascertain the relation between excessively raised values of homocysteine during the antenatal period and unfavourable pregnancy outcomes.	180 pregnant women participated in the research, 57 of whom were exposed and 123 of whom were not.	The study provided the required proof that unusually high homocysteine levels are linked to pregnancy-related hypertension disorders and unfavourable pregnancy outcomes. Strongly conceived investigations and experiments are also required to better study the phenomena. Furthermore, it underlines the need for a quick and easy action that can help anticipate and avoid negative perinatal outcomes: assessing the much-ignored homocysteine levels throughout pregnancy.
10	Oluwole et al. 2020 [16]	Prospective cohort study	The study's goal was to find out how high maternal homocysteine levels affected the outcomes of pregnant Nigerian women in Lagos.	200 participants were taken in the study and divided into 2 groups.	In Lagos, there was a comparatively low rate of Hyperhomocysteinemia among mothers. Future prevention of these negative consequences may be affected by the associations between Hyperhomocysteinemia and unfavourable pregnancy outcomes.