Figure 1. 
 Graphs showing unadjusted (univariable) association between the following continuous baseline variables and a live birth in the second complete cycle of IVF.  ( a ) woman’s age (years), ( b ) duration of infertility (years), ( c ) year of second complete cycle started, ( d ) number of eggs retrieved at the first complete cycle and ( e ) time interval (months) between egg retrievals in the first and second complete cycles. Each panel depicts the probability of live birth (solid curve) with 95% CIs as a function of the baseline variable.