P-531: Lack of prognostic value of maternal serum ghrelin levels in early IVF pregnancies for gestational outcome and altered post-prandial responses

Abstract

Ghrelin is a pleiotropic hormone recently involved in the control of growth and metabolism, whose circulating levels fluctuate in relation to food intake and body mass index. Elevated RNA-Ghrelin levels in the decidualized endometrium have been reported and it is present in the human and rat placenta showing a pregnancy related time course expression. The aim of this study is to evaluate the clinical value of maternal Ghrelin serum measurements at very early stages of IVF pregnancies. In addition, ghrelin responses to food intake were explored at early gestation. Prospective study. One hundred and seven patients who underwent embryo transfer were prospectively recruited. On d-16 and 23 after oocyte retrieval, the patients were subjected to blood sampling after overnight fasting, for determination of serum ghrelin, hCGβ and progesterone levels. In addition, ghrelin levels were assayed in these groups, 2-h after ingestion of a fixed-calorie meal. The subjects were divided into the following groups: women that failed to conceive (non-pregnant; n=36), women who had a viable intra-uterine pregnancy (on-going pregnancy), either singleton (n=28) or twin (n=24), and abnormal pregnancies: biochemical (n=9) and miscarriage (n=7). There was no significant difference in patient′s age, number of oocytes retrieved, and embryos transferred during the IVF cycles among groups. On 16th and 23 th day, the mean plasma ghrelin concentration after an overnight fasting were similar among the different groups. Interestingly, while in non-pregnant subjects maternal ghrelin levels showed an expected ∼15% decline after meal ingestion, such a post-prandial decrease was not detected in pregnant women, selectively at d-16 after oocyte retrieval (p < 0.05). Maternal ghrelin levels at early gestational age do not appear to pose diagnostic (as marker) or prognostic value for pregnancy outcome in IVF procedures. The lack of decline in serum ghrelin levels in response to meal ingestion reported herein is likely to be a novel component of the extensive metabolic adaptations that take place at early pregnancy. Longer series and at different pregnancy weeks are needed to better address this issue.