Cryopreserved embryo transfer is an independent risk factor for placenta accreta.
OBJECTIVE
To explore the association between cryopreserved embryo transfer (CET) and risk of placenta accreta among patients utilizing in vitro fertilization (IVF) and/or intracytoplasmic sperm injection (ICSI).


METHODS
Case-control study.


METHODS
Academic medical center.


METHODS
All patients using IVF and/or ICSI, with autologous or donor oocytes, undergoing fresh or cryopreserved transfer, who delivered a live-born fetus at ≥24 weeks of gestation at our center, from 2005 to 2011 (n = 1,571), were reviewed for placenta accreta at delivery.


METHODS
Cases of accreta (n = 50) were matched by age and prior cesarean section to controls (1:3) without accreta. The association between CET and accreta was modeled using conditional logistic regression, controlling a priori for age and placenta previa. Receiver operating characteristic curves were used to determine thresholds of endometrial thickness and peak serum E2 levels related to accreta.


METHODS
Placenta accreta.


RESULTS
Univariate predictors of accreta were non-Caucasian race (odds ratio [OR] 2.85, 95% confidence interval [CI] 1.25-6.47); uterine factor infertility (OR 5.80, 95% CI 2.49-13.50); prior abdominal or laparoscopic myomectomy (OR 7.24, 95% CI 1.92-27.28); and persistent or resolved placenta previa (OR 4.25, 95% CI 1.94-9.33). In multivariate analysis, we observed a significant association between CET and accreta (adjusted OR 3.20, 95% CI 1.14-9.02), which remained when analyses were restricted to cases of accreta with morbid complications (adjusted OR 3.87, 95% CI 1.08-13.81). Endometrial thickness and peak serum E2 level were each significantly lower in CET cycles and those with accreta.


CONCLUSIONS
Cryopreserved ET is a strong independent risk factor for accreta among patients using IVF and/or ICSI. A threshold endometrial thickness and a "safety window" of optimal peak E2 level are proposed for external validation.
Department of Obstetrics, Gynecology and Reproductive Biology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts. Electronic address: dkaser@partners.org.
Daniel J
DJ
Kaser
Department of Obstetrics, Gynecology and Reproductive Biology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
Alexander
A
Melamed
Department of Obstetrics, Gynecology and Reproductive Biology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
Charles L
CL
Bormann
Department of Obstetrics, Gynecology and Reproductive Biology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
Dale E
DE
Myers
Department of Obstetrics, Gynecology and Reproductive Biology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts; Department of Medicine at Channing Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts; Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts.
Stacey A
SA
Missmer
Department of Obstetrics, Gynecology and Reproductive Biology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
Brian W
BW
Walsh
Department of Obstetrics, Gynecology and Reproductive Biology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
Catherine
C
Racowsky
Department of Obstetrics, Gynecology and Reproductive Biology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
Daniela A
DA
Carusi
D000046:Academic Medical Centers; D000328:Adult; D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood; D001900:Boston; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D015925:Cryopreservation; D016208:Databases, Factual; D004624:Embryo Transfer / Q000009:adverse effects*; D004717:Endometrium / Q000473:pathology; D004958:Estradiol / Q000097:blood; D005260:Female; D005307:Fertilization in Vitro / Q000009:adverse effects*; D005865:Gestational Age; D006801:Humans; D010535:Laparoscopy / Q000009:adverse effects; D050498:Live Birth; D016015:Logistic Models; D015999:Multivariate Analysis; D016017:Odds Ratio; D010921:Placenta Accreta / Q000097:blood / Q000175:diagnosis / Q000208:ethnology / Q000209:etiology*; D011237:Predictive Value of Tests; D011247:Pregnancy; D018873:Pregnancy Rate; D012372:ROC Curve; D012307:Risk Factors; D020554:Sperm Injections, Intracytoplasmic / Q000009:adverse effects; D016896:Treatment Outcome; D063186:Uterine Myomectomy / Q000009:adverse effects / Q000379:methods
D015415:Biomarkers; D004958:Estradiol
Adherent placenta; IVF; estradiol safety window; frozen embryo; trophoblast