Introduction
Hydatidiform mole (HM) is a gestational trophoblastic disease, which is characterized by abnormal trophoblastic proliferation and hydrophic degeneration in the placenta [1]. HM may lead to several complications, such as massive bleeding during pregnancy, uterine rupture when performing evacuation, and transforming to gestational trophoblastic neoplasia, so it negatively affects a woman’s health both during pregnancy and for rest of her life [2]. Although several studies have identified interesting pathogenetic pathways that might contribute to the development of HM, such as genetic defects in fertilization phase, NLRP7 gene mutations, and dietary changes, the exact ethiology is still not fully elucidated [3-5].
Carnitine (L-3-hydroxy-4-N-N-N-trimethylaminobutyrate) is an essential compound, that is synthesized in only a few organs, such as brain, liver, and kidney. It has a functional role in the intracellular transport of long-chain fatty acids for β-oxidation process [6,7]. Fatty acids are energy substrates that provide the energy necessary for growth, maturation, and transport functions of placenta. Since carnitine biosynthesis in the fetus is insufficient, transport of maternal carnitine through the placenta plays an important role for fetal development [8].
Amino acids are biologically important organic molecules, which play central roles both in building of proteins and as intermediates in metabolism of cells and tissues. The free amino acids (FAAs) are distributed throughout the body to participate the active metabolic system [9]. Previous studies have determined that metabolomics analysis, a new method measuring the metabolites in all tissue or biofluid samples, could usable in several diseases which has uncontrolled cell growth [10-12]. In a study in normal pregnant women, the elevated levels of FAAs were found compatible with syncytiotrophoblast activity in the intervillous space [13]. Since it is well known that there are hyperactivity and excess proliferation in trophoblastic cells of molar pregnancies, we hypothesized that FAA levels would be lower in plasma of HM patients than in normal pregnants due to the enhanced metabolism of trophoblastic cells. To the best of our knowledge, this is the first study in the literature which compares plasma FAA and carnitine levels in HM patients with those of healthy pregnant women.