Expressions of growth differentiation factor-9 on granulosa cells of infertile women with endometriosis undergoing in vitro fertilization

Endometriosis may cause ovarian physiology disturbances and one of them, by affecting folliculogenesis that leads to a decreased oocyte quality. The oocyte plays an important role in regulating and promoting follicle growth by oocyte growth factors production. Several growth factors have been identified in human oocytes, including growth differentiation factor-9 (GDF-9). However, studies on GDF-9 expression in the granulosa cells of infertile women with endometriosis are sparse. To investigate the expression of GDF-9 mRNA in the granulosa cells of endometriosis patients undergoing in vitro fertilization (IVF) and identify the correlation between GDF-9 expression and oocyte quality. This cross-sectional study was conducted at the Yasmin IVF Clinic and Dr. Sander B Clinic, Jakarta from July 2014 to July 2017. In total, 50 granulosa cell samples were collected from 25 women with endometriosis and 25 controls who were healthy. The granulosa cell samples were collected at the time of oocyte retrieval. GDF-9 mRNA expression was investigated by real-time PCR. The numbers of retrieved oocytes, mature oocytes, and the oocyte morphology score were lower in patients with endometriosis than in controls; the difference was statistically significant. GDF-9 mRNA expression levels were quantitatively lower in the endometriosis groups than in the control group (5.05 [0.00002-3523.0] ng/mL vs. 81.93 [1.47-32450] ng/μL; p = 0.01). However, no correlation was obtained between GDF-9 expression levels and oocyte quality (oocyte morphology score and fertilization rate). The GDF9 mRNA level was lower in the endometriosis group than in the control group. However, no direct relationship was noted between individual GDF-9 level and oocyte quality. Hence, large-scale studies are needed to confirm whether GDF-9 expression is correlated with the oocyte quality and to ascertain whether GDF-9 has the potential for use as a new molecular marker to predict oocyte developmental competency.