Second try: who returns for additional assisted reproductive technology treatment and the effect of a prior assisted reproductive technology birth.

OBJECTIVE: To evaluate the effect of a prior assisted reproductive technology (ART) live birth on subsequent live-birth rates.
DESIGN: Historical cohort study.
SETTING: Clinic-based data. PATIENT(S): The study population included 297,635 women with 549,278 cycles from 2004 to 2010 from the Society for Assisted Reproductive Technology Clinic Outcome Reporting System. Try 1 refers to ART cycles up to and including the first live birth, try 2 to ART cycles after a first live birth. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Live-birth rates by cycle number, try number, and oocyte source. RESULT(S): Younger women at try 1 are more likely to return for try 2. Women returning for try 2 were more likely to have had an ART singleton versus multiple birth (33.2% after a try 1 singleton versus 8.1% after twins and 4.9% after triplets) and were less likely to have a diagnosis of diminished ovarian reserve or tubal factors. Live-birth rates were significantly higher for try 2 compared with try 1 for autologous fresh cycles, averaging 7.7 percentage points higher over five cycles. Live-birth rates were not significantly different for try 2 versus try 1 with thawed autologous cycles or either fresh or thawed donor cycles. CONCLUSION(S): These results indicate that when fresh autologous oocytes can be used, live-birth rates per cycle are significantly greater after a prior history of an ART live birth.