Precision of progesterone measurements with the use of automated immunoassay analyzers and the impact on clinical decisions for in vitro fertilization.

OBJECTIVE: To compare the precision of progesterone measurements obtained with the use of immunoassays and of liquid chromatography-tandem mass spectrometry (LC-MS/MS). DESIGN: Comparative study. SETTING: Academic, private practice, and in vitro fertilization (IVF) research centers. PATIENT(S): A total of 189 human serum samples were collected during controlled ovarian hyperstimulation and early pregnancy in women undergoing IVF. INTERVENTION(S): Serum progesterone pools (n = 10; 0.2-4 ng/mL) were sent to four laboratory centers that used four different automated immunoassay analyzers. Progesterone was measured by immunoassay in triplicate at three separate time points (n = 9 per pool) and by LC-MS/MS in triplicate once (n = 3 per pool). MAIN OUTCOME MEASURE(S): Inter- and intraassay coefficients of variation (CVs) of progesterone measurements were compared for each analyzer and LC-MS/MS. RESULT(S): Progesterone measurements by immunoassay were highly correlated with those by LC-MS/MS. Only two analyzers had intraassay CVs <10% at all three experimental time points, and only two analyzers had an interassay CV <10%. Mean progesterone levels by the analyzers were different across multiple progesterone pools. CONCLUSION(S): Our results indicate that progesterone threshold measurements used for IVF clinical decisions should be interpreted cautiously and based on laboratory- and method-specific data. A validated progesterone standard incorporated into daily immunoassays could improve medical decision accuracy.

Insulin and insulin-like growth factor stimulation of vascular endothelial growth factor production by luteinized granulosa cells: comparison between polycystic ovarian syndrome (PCOS) and non-PCOS women.

CONTEXT: Vascular endothelial growth factor A (VEGF-A) is a potent cytokine that promotes angiogenesis and vascular permeability. After controlled ovarian stimulation (COS) for in vitro fertilization (IVF), excessive VEGF-A production can occur, particularly in women with polycystic ovarian syndrome (PCOS); however, it is unclear whether the regulation of VEGF-A production is different between PCOS and non-PCOS women. OBJECTIVE: The aim of this study was to determine whether there were differences in the dose- and time-dependent effects of insulin and IGFs on VEGF-A production by luteinized granulosa cells (LGCs) from women with and without PCOS. DESIGN AND SETTING: A prospective comparative experimental study was conducted at an institutional practice. PATIENTS: Patients included six PCOS and six non-PCOS women undergoing COS and IVF. INTERVENTIONS: Interventions included COS for IVF. MAIN OUTCOME MEASURES: VEGF-A levels in culture media were collected daily for 3 d from LGCs after incubation with variable doses of insulin, IGF-I, and IGF-II in the presence and absence of LH. RESULTS: In both study groups, exposure to LH alone did not alter VEGF-A levels. However, insulin or IGF increased VEGF-A levels within 1 d and appeared to synergize with LH at 3 d. VEGF-A production by non-PCOS LGCs was more sensitive to IGF exposure, whereas PCOS cells were more sensitive to insulin. Although an increase in DNA content (P < 0.05) was noted in cultures of PCOS cells, progesterone levels were lower compared with non-PCOS LGCs. CONCLUSION: Insulin and IGFs promote VEGF-A production in LGCs, but the response patterns are different when cells from PCOS and non-PCOS women are compared.