Cycle day 2 insulin-like growth factor-1 serum levels as a prognostic tool to predict controlled ovarian hyperstimulation outcomes in poor responders

Pleiotropic Effects of IGF1 on the Oocyte

A woman’s endocrine system plays a crucial role in orchestrating cellular interactions throughout her life. The growth hormone (GH) and insulin-like growth factor (IGF) system appears to impact crucial reproductive events and cell types of the ovary, such as granulosa cells, theca cells, and oocytes. Further, IGF1 is a cornerstone during embryonic development and influences predominantly developing and pre-antral follicles. In this commentary, we will emphasize the pleiotropic effects of IGF1 on physiological processes inside the egg. Herein, we will provide a brief overview on IGF1 related cell signal transduction pathways during the maturation and aging of oocytes. We aim to elucidate from a molecular and biochemical point of view if IGF1 in women with metabolic imbalances such as obesity or diabetes could be used in clinics as a novel, reliable estimator for the developmental competence of an oocyte.

Importance of IGF-I levels in IVF: potential relevance for growth hormone (GH) supplementation

Purpose

Growth hormone (GH) supplementation in association with in vitro fertilization (IVF) is worldwide again increasing, even though study outcomes have been discrepant. Since GH acts via insulin-like growth factor-1 (IGF-1), its utilization in IVF would only seem to make sense with low IGF-1. We, therefore, determined whether IGF-I levels affect IVF outcomes.

Methods

Retrospectively, 302 consecutive first fresh, non-donor IVF cycles were studied, excluding patients on GH supplementation. Patients were divided into 3 subgroups: IGF-1 in lower 25th percentile (group A, < 132 ng/mL, n = 64); 25th–75th percentile (B, 133–202 ng/mL, n = 164), and upper 25th percentile (C, > 202 ng/mL, n = 74). IGF-1 was tested immunochemiluminometric with normal range at 78–270 ng/mL. Because of the study patients’ adverse selection and low pregnancy chances, the main outcome measure for the study was cycle cancellation. Secondary outcomes were oocyte numbers, embryos transferred, pregnancies, and live births.

Results

Group A was significantly older than B and C (P = 0.019). IGF-1 decreased with increasing age per year by 2.2 ± 0.65 ng/mL (P = 0.0007). FSH was best in group B and worst in A (trend, P = 0.085); AMH was best in B and worst in A (N.S.). Cycle cancellations were lowest in C (11.6%) and highest in A (25.0%; P = 0.042). This significance further improved with age adjustment (P = 0.021). Oocytes, embryo numbers, pregnancies, and live birth rates did not differ, though oocyte numbers trended highest in B.

Conclusions

Here presented results support the hypothesis that IGF-1 levels affect IVF outcomes. GH treatments, therefore, may be effective only with low IGF-1.

Measuring IGF-1 and IGFBP-3 Profiles in Women Seeking Assisted Reproduction; Relationship to Clinical Parameters (Study 1)

This study examines the IGF serum profile (IGF-1, IGFBP-3 and the IGF Ratio) from 1633 women who undertook an Assessment Cycle prior to any treatment by assisted reproduction. The idea is to progressively study the IGF profile with a view to identify those women who may be classified as having adult growth hormone deficiency (AGHD) and who may benefit from specific dynamic endocrinological testing to identify a potential benefit from growth hormone adjuvant treatment. This first study evaluates the IGF profile on clinical parameters, namely age, body mass index (BMI) and stature. The study shows a significant linear reduction in IGF-1 levels across the four age groups (<35 years, 35–39 years, 40–44 years and ≥45 years; p < 0.001). However, there was no variation in IGFBP-3 levels but the IGF Ratio showed a progressive linear elevation with advancing age (p < 0.001). With respect to both BMI and stature, none of the IGF profile parameters showed any variation. We conclude that further studies are warranted to examine the notion of underlying AGHD in the causation of the well-known feature of age-related poor prognosis in assisted reproduction.