Cryopreserved embryo transfer is an independent risk factor for placenta accreta  Daniel J. Kaser, M.D., Alexander Melamed, M.D., M.P.H., Charles L. Bormann, Ph.D., Dale E. Myers, Sc.M., Stacey A. Missmer, Sc.D., Brian W. Walsh, M.D., Catherine Racowsky, Ph.D., Daniela A. Carusi, M.D., M.Sc.  Fertility and Sterility  Volume 103, Issue 5, Pages 1176-1184.e2 (May 2015) DOI: 10.1016/j.fertnstert.2015.01.021 Copyright © 2015 American Society for Reproductive Medicine Terms and Conditions

Figure 1 Flow diagram showing method of case definition for 51 cases of placenta accreta culled from a cohort who used IVF and/or ICSI (n = 1,571) and delivered ≥1 live-born infant at ≥24 weeks of gestational age at our hospital, from 2005 to 2011. Note that 1 delivery was excluded, as the patient had already contributed an accreta to this analysis in a prior pregnancy. The proportion of cases that were classified as clinically morbid is likewise shown. Here, morbidity was defined as: hemorrhage (>1,000 mL of blood loss, regardless of mode of delivery, or any blood transfusion); nonroutine procedures to stop excess blood loss (gravid hysterectomy or uterine artery embolization); or additional procedures to remove the placenta (see Materials and Methods section for details). Fertility and Sterility 2015 103, 1176-1184.e2DOI: (10.1016/j.fertnstert.2015.01.021) Copyright © 2015 American Society for Reproductive Medicine Terms and Conditions

Figure 2 Endometrial thickness and risk of placenta accreta among patients using IVF and/or ICSI (n = 1,571). (A) Receiver operating characteristic curve for endometrial thickness threshold as a diagnostic test for accreta. Area under the curve was 0.649. (B) Distribution of Youden's J-statistic (sensitivity + specificity − 1) for endometrial thickness. An optimal threshold of endometrial thickness was chosen as 9.7 mm. (C) Histogram of patients with and without accreta according to endometrial thickness. (D) Scatterplot of risk difference for accreta according to endometrial thickness. A positive value indicates an excess risk of accreta. Fertility and Sterility 2015 103, 1176-1184.e2DOI: (10.1016/j.fertnstert.2015.01.021) Copyright © 2015 American Society for Reproductive Medicine Terms and Conditions

Figure 3 Peak serum E2 and risk of placenta accreta among patients using IVF and/or ICSI (n = 1,571). (A) Receiver operating characteristic curve for peak serum E2 threshold. Area under the curve was 0.603. (B) Distribution of Youden's J-statistic for peak E2. One proposed threshold of peak serum E2 level was chosen as 732 pg/mL, as it optimized the absolute difference between true and false positives and additionally happened to be the median E2 for morbid accretas. Given the multimodal nature of this curve, however, other relevant threshold values may exist. (C) Histogram of patients with and without accreta, according to peak serum E2 level. (D) Scatterplot of risk difference for accreta, according to peak serum E2 level. A positive value indicates an excess risk of accreta. Fertility and Sterility 2015 103, 1176-1184.e2DOI: (10.1016/j.fertnstert.2015.01.021) Copyright © 2015 American Society for Reproductive Medicine Terms and Conditions