Kisspeptin and Hematologic Parameters as Predictive Biomarkers for First-Trimester Abortions

Platelet to lymphocyte and neutrophil to lymphocyte ratio in the first trimester of pregnancy, are they useful for predicting spontaneous miscarriage? A case-control study

BACKGROUND

In 15% of all clinical pregnancies, a miscarriage can occur, but the exact cause of this phenomenon is not fully understood. However, it is believed that a faulty placenta, which triggers an inflammatory response in the mother's body, may be one of the causes. Medical literature has increasingly focused on 2 indicators of inflammation, the platelet-lymphocyte ratio (PLR) and neutrophil-lymphocyte ratio (NLR). Despite this, there has yet to be a study conducted that examines the rates of PLR and NLR in cases of miscarriage.

OBJECTIVE

This study aims to determine whether there is an increase in complete blood count inflammatory parameters such as NLR and PLR in women who experience miscarriages.

MATERIALS AND METHODS

This retrospective case-control study was conducted from March 2021 to March 2022, across 3 academic hospitals in Tehran, Iran. A total of 240 participants were enrolled comprising individuals with either miscarriages or normal pregnancies (n = 120/each). Data were collected from the medical records of participants aged between 18-42 yr old, with gestational age ranging from 6-13 wk. The demographic information, including age, body mass index, parity, history of abortion, number of abortions, number of living children, hematocrit and hemoglobin levels, platelet distribution width (PDW), PLR, NLR, mean platelet volume, and platelet were extracted from their records. The gestational age was also recorded.

RESULTS

A total of 240 participants were recruited for the study. PDW, NLR, PLR, and lymphocyte values were higher in the miscarriage group compared to the healthy normal pregnant women (p < 0.001). Mean platelet volumes were found to be lower in the miscarriage group compared to the healthy normal pregnant women (p < 0.001).

CONCLUSION

Although, no statistically significant difference was observed in the hemoglobin, hematocrit, platelets, and neutrophils in these 2 groups of pregnant women. The higher inflammatory markers including PDW, NLR, and PLR could potentially aid in the speculation of defective placentation as a contributing factor to the development of miscarriage. Measurement of these markers may be useful to predict pregnancy leading to miscarriage.

Kisspeptin in the Prediction of Pregnancy Complications

Kisspeptin and its receptor are central to reproductive health acting as key regulators of the reproductive endocrine axis in humans. Kisspeptin is most widely recognised as a regulator of gonadotrophin releasing hormone (GnRH) neuronal function. However, recent evidence has demonstrated that kisspeptin and its receptor also play a fundamental role during pregnancy in the regulation of placentation. Kisspeptin is abundantly expressed in syncytiotrophoblasts, and its receptor in both cyto- and syncytio-trophoblasts. Circulating levels of kisspeptin rise dramatically during healthy pregnancy, which have been proposed as having potential as a biomarker of placental function. Indeed, alterations in kisspeptin levels are associated with an increased risk of adverse maternal and foetal complications. This review summarises data evaluating kisspeptin's role as a putative biomarker of pregnancy complications including miscarriage, ectopic pregnancy (EP), preterm birth (PTB), foetal growth restriction (FGR), hypertensive disorders of pregnancy (HDP), pre-eclampsia (PE), gestational diabetes mellitus (GDM), and gestational trophoblastic disease (GTD).

The Role of Kisspeptin in the Pathogenesis of Pregnancy Complications: A Narrative Review

Kisspeptins are the family of neuropeptide products of the KISS-1 gene that exert the biological action by binding with the G-protein coupled receptor 54 (GPR54), also known as the KISS-1 receptor. The kisspeptin level dramatically increases during pregnancy, and the placenta is supposed to be its primary source. The role of kisspeptin has already been widely studied in hypogonadotropic hypogonadism, fertility, puberty disorders, and insulin resistance-related conditions, including type 2 diabetes mellitus, polycystic ovary syndrome, and obesity. Gestational diabetes mellitus (GDM), preeclampsia (PE), preterm birth, fetal growth restriction (FGR), or spontaneous abortion affected 2 to 20% of pregnancies worldwide. Their occurrence is associated with numerous short and long-term consequences for mothers and newborns; hence, novel, non-invasive predictors of their development are intensively investigated. The study aims to present a comprehensive review emphasizing the role of kisspeptin in the most common pregnancy-related disorders and neonatal outcomes. The decreased level of kisspeptin is observed in women with GDM, FGR, and a high risk of spontaneous abortion. Nevertheless, there are still many inconsistencies in kisspeptin concentration in pregnancies with preterm birth or PE. Further research is needed to determine the usefulness of kisspeptin as an early marker of gestational and neonatal complications.