Cumulative live birth rates for women returning to ART treatment for a second ART-conceived child

• Published in: Human reproduction (Oxford) 2020-06, Vol.35 (6), p.1432-1440
• Main Authors: Paul, Repon C, Fitzgerald, Oisin, Lieberman, Devora, Venetis, Christos, Chambers, Georgina M
• Format: Article
• Language: English
• Subjects: Australia; Birth Rate; Child; Cohort Studies; Female; Fertilization in Vitro; Humans; Live Birth; New Zealand; Pregnancy
• ISSN: 0268-1161; 1460-2350
• DOI: 10.1093/humrep/deaa030

Abstract STUDY QUESTION What are the success rates for women returning to ART treatment in the hope of having a second ART-conceived child. SUMMARY ANSWER The cumulative live birth rate (LBR) for women returning to ART treatment was between 50.5% and 88.1% after six cycles depending on whether women commenced with a previously frozen embryo or a new ovarian stimulation cycle and the assumptions made regarding the success rates for women who dropped-out of treatment. WHAT IS KNOWN ALREADY Previous studies have reported the cumulative LBR for the first ART-conceived child to inform patients about their chances of success. However, most couples plan to have more than one child to complete their family and, for that reason, patients commonly return to ART treatment after the birth of their first ART-conceived child. To our knowledge, there are no published data to facilitate patient counseling and clinical decision-making regarding the success rates for these patients. STUDY DESIGN, SIZE, DURATION A population-based cohort study with 35 290 women who commenced autologous (using their own oocytes) ART treatment between January 2009 and December 2013 and achieved their first treatment-dependent live birth from treatment performed during this period. These women were then followed up for a further 2 years of treatment to December 2015, providing a minimum of 2 years and a maximum of 7 years of treatment follow-up. PARTICIPANTS/MATERIALS, SETTING, METHODS Cycle-specific LBR and cumulative LBR were calculated for up to six complete ART cycles (one ovarian stimulation and all associated transfers). Three cumulative LBR were calculated based on the likelihood of success in women who dropped-out of treatment (conservative, optimal and inverse probability-weighted (IPW)). A multivariable logistic regression model was used to predict the chance of returning to ART treatment for a second ART-conceived child, and a discrete time logistic regression model was used to predict the chance of achieving a second ART-conceived child up to a maximum of six complete cycles. The models were adjusted for patient characteristics and previous and current treatment characteristics. MAIN RESULTS AND THE ROLE OF CHANCE Among the women who had their first ART-conceived live birth, 15 325 (43%) returned to treatment by December 2015. LBRs were consistently better in women who recommenced treatment with a previously frozen embryo, compared to women who underwent a new ovarian stimulation cy