The predictive significance of serum cystatin C and free sub unit of β-Human chorionic gonadotropin in pregnant women with preeclampsia in Lagos

Background: Preeclampsia (PE) is a multi-systemic progressive disorder that is unique to human pregnancy, occurring usually after 20 weeks of gestation. Useful biochemical markers to be utilized for early prediction of preeclampsia continue to elude us. The search for biomarkers is aimed identifying women at increased risk of developing PE, so that medical interventions may be instituted very early in pregnancy to ameliorate its occurrence and improve maternal and fetal outcome. Aim: This study aimed to determine the association between serum levels of Cystatin C and/or free β-subunit of hCG measured in early pregnancy and the development of pre-eclampsia and its severity. Methods: This was a prospective cohort study of 290 pregnant women recruited during routine antenatal care, at the gestational age of between 13 and 19 weeks. After obtaining an informed consent from each participant, a structured questionnaire was used to collection relevant information followed by the collection of 5 mL of venous blood sample. Serum cystatin C and free sub unit of β-hCG levels were determined by standard enzyme-linked immunosorbent assay (ELISA) method. All participants were followed up till delivery and those who developed preeclampsia was classified as mild and severe preeclampsia. Data were entered and analyzed using STATA version 16 statistical software. Hypothesis testing was done using chi-square test for categorical variables, and the independent-samples t-test and ANOVA for numerical variables. Results: We found significantly elevated serum levels of cystatin C and free subunit of β-hCG in women who developed preeclampsia, (p < 0.002 and 0.001) respectively. Conclusion: Our study has shown that in a healthy population of pregnant women that elevated serum levels of cystatin C and free beta hCG concentration measured in early second trimester were associated with an increased risk of developing preeclampsia and its severity. This suggests that the combination of these analytes may have a role as a marker of pre-eclampsia and its severity especially when used in combination.