Role of total antioxidant capacity in the differential growth of human embryos in vitro.

OBJECTIVE The objective of this study was to examine the relationship of early human embryonic development parameters with day 1 culture media total antioxidant levels (day 1 TAC). DESIGN Prospective study. SETTING Patients undergoing assisted reproduction (ART) in a teaching hospital. PATIENT(S) Patients undergoing conventional IVF (n = 153; 167 cycles) and intracytoplasmic sperm injection (ICSI; n = 105; 116 cycles) were included. Both fertilization and early cultures were performed in human tubal fluid (HTF) with 5% serum substitute supplement. INTERVENTION(S) Levels of total antioxidants in the central well (sample) and the outer well (control) of each embryo culture dish were measured. MAIN OUTCOME MEASURE(S) Fertilization rate and embryo quality at days 3 and 5 were recorded for each cycle. Age, parity, and demographic features were also compared. RESULT(S) After controlling for all demographic and clinical variables, day 1 TAC was related to fertilization rates in both groups of patients. Day 1 TAC was significantly related to high (>7) day 3 cell number, low (<10%) fragmentation rate, and blastocyst development rate in both conventional IVF and ICSI cycles. Day 1 TAC was related to pregnancy in ICSI but not conventional IVF cycles. CONCLUSION(S) Day1 TAC appears to be an important biochemical marker for early embryonic growth. Decreased embryonic fragmentation, enhanced cleavage rate, and increased blastocyst development rate may be partially related to day 1 TAC in the culture media. Whether this relationship is a cause or effect needs further assessment.