This study was approved by the Gumushane University Ethics Committee(Project number:2022/E-95674917) and was conducted in accordance with the Declaration of Helsinki. All participants included in the study gave written and verbal informed consent prior to being enrolled in the study.
In this cross-sectional study, the HEG group consisted of 45 patients aged between 21 and 34 who were admitted for nause and vomiting during pregnancy to the Ordu University Education and Research Hospital Gynecology and Obstetrics Clinic between January 2018 and January 2022. The control group consisted of 44 pregnant women who applied to the same clinic for routine antenatal follow up and were matched in terms of chronological age, gestational age, and body mass index (BMI). Patients with diabetes or obesity, peptic ulcer or gastritis, liver and/or gallbladder disease (cholangitis or gallstones), thyroid dysfunction, urinary tract infection, coeliac disease, cardiovascular or renal diseases were excluded from our study. We also excluded any patients who has nausea and vomiting and any patients who has threatened miscarriage,as vaginal bleeding during pregnancy may affect ADAMTS levels . Multiple pregnancies and/or pregnancies obtained by assisted reproductive techniques, gestational trophoblastic disease, and autoimmune disease conditions were also not included in the study.
HEG was diagnosed if there was a persistent vomiting resulting in ketonuria and/or ketonemia leading to weight loss and volume reduction exceeding 5% of pre-pregnancy weight.
Women who vomited more than 3 times a day due to HEG and/or who had a positive urine ketone test result and/or were hospitalized for HEG 2 or more times. BMI was measured by dividing the weight in kilograms by the height in meters squared (kg/m2). Doctors performed the first transabdominal pregnancy ultrasonography using a 3.5 MHz transabdominal transducer (General Electric Logiq A5 ultrasound machine, Milwaukee, USA), and the gestational age was estimated according to the first trimester ultrasonographic value of fetal crown-rump length.
All laboratory analyses for each patient were performed in the early morning after an overnight fast of 8–12 h. We first hydrated the patients with 1000 cc RL solution and collected serum samples after sufficient urine output. We did not dilute the serum samples.
We evaluated complete blood count, thyroid-stimulating hormone (TSH), T3, T4, fasting plasma glucose, BMI, aspartate transferase, alanine transferase (ALT), blood urea nitrogen (BUN), and creatinine levels.
Measurement of serum ADAMTS-1 Levels
Venous blood samples were collected from each participant’s antecubital vein after at least 8 h of fasting and then separated by centrifugation at 4000 rpm for 10 min. In order to measure serum ADAMTS-1 protease, we obtained blood samples after we diagnosed HEG and then we stored the materials at -80 ˚C until the study time. Frozen serum samples were thawed to room temperature and were not diluted. ADAMTS-1 levels were measured with a commercially available enzyme-linked immunosorbent assay (ELISA) kit (Hangzhou Eastbiopharm Co., Ltd., China) and this ELISA kit was specific for ADAMTS-1.The test procedure was completed in accordance with the manufacturer’s instructions using biotin double-antibody sandwich technology. Serum samples were added onto wells that were previously coated with ADAMTS-1 monoclonal antibodies. Biotin labelled anti-ADAMTS-1 antibodies and streptavidin-HRP were added to form immune complexes. Following incubation, unbound enzymes were removed by washing. Chromogen solutions A and B were then added. Stop solution was used to stop the reaction and formed yellow color’s optical density was measured by using a microplate reader at 450 nm, which was proportional to the amount of ADAMTS-1. ADAMTS-1 serum levels, as ng/ml, were interpolated from a standard curve. The intra-and interassay variation coefficients of the kit were smaller than 9% and 11%, respectively.
Statistical analysis was performed using SPSS version 22. Descriptive statistics, such as mean, standard deviation, and median (minimum–maximum), were used while statistically defining normal and non-normal variables. Normality was tested using the Shapiro–Wilk test. After performing the normality test, parametric (independent samples t-test) and non-parametric (Mann–Whitney U) analysis tests were used to detect the differences between the groups. Spearman’s rank-order correlation method was used for univariate correlations. To reveal the predictive value of ADAMTS-1 protein for HEG, the receiver operator characteristics curve (ROC) analysis was applied. A priori power analysis for the two independent means was done using G*Power software (Universitat Kiel, Kiel, Germany) to define an adequate sample size with a large effect size (α: 0.05 and β: 0.95). We considered p value less than 0.05 as statistically significant.