Bruce S Shapiro1, Said T Daneshmand2, Carrie E Bedient2, Forest C Garner2. 1. Fertility Center of Las Vegas and University of Nevada School of Medicine, Las Vegas, Nevada. Electronic address: bsshapiro@aol.com. 2. Fertility Center of Las Vegas and University of Nevada School of Medicine, Las Vegas, Nevada.
Abstract
OBJECTIVE: To estimate birth weight differences between patients randomized to fresh or thawed ET. DESIGN: Post hoc analysis of results from two similar randomized trials. SETTING: Private fertility center. PATIENT(S): One hundred thirty-four first-time IVF patients, ages 18-40 years at oocyte retrieval, who had live birth. INTERVENTION(S): Patients were randomly assigned to have either fresh blastocyst transfer or all bipronuclear oocytes frozen followed by thaw, extended culture, and blastocyst transfer in a subsequent cycle. Preimplantation genetic screening was not allowed. MAIN OUTCOME MEASURE(S): Mean birth weight. RESULT(S): After allowing for the contributions of multiple significant variables (gestational age at birth, the presence of a vanished twin, number of infants delivered) in multiple linear regression, the adjusted mean birth weight was 166 g (95% confidence interval, 43-290 g) lower after fresh blastocyst transfer when compared with transfer of blastocysts derived from thawed bipronuclear oocytes. CONCLUSION(S): Birth weights are lower in cycles with fresh blastocyst transfer after controlled ovarian stimulation than in transfers of frozen-thawed embryos in the absence of ovarian stimulation. This finding confirms similar results reported in many retrospective studies. CLINICAL TRIAL REGISTRATION NUMBERS: NCT00963625 and NCT00963079.
OBJECTIVE: To estimate birth weight differences between patients randomized to fresh or thawed ET. DESIGN: Post hoc analysis of results from two similar randomized trials. SETTING: Private fertility center. PATIENT(S): One hundred thirty-four first-time IVF patients, ages 18-40 years at oocyte retrieval, who had live birth. INTERVENTION(S): Patients were randomly assigned to have either fresh blastocyst transfer or all bipronuclear oocytes frozen followed by thaw, extended culture, and blastocyst transfer in a subsequent cycle. Preimplantation genetic screening was not allowed. MAIN OUTCOME MEASURE(S): Mean birth weight. RESULT(S): After allowing for the contributions of multiple significant variables (gestational age at birth, the presence of a vanished twin, number of infants delivered) in multiple linear regression, the adjusted mean birth weight was 166 g (95% confidence interval, 43-290 g) lower after fresh blastocyst transfer when compared with transfer of blastocysts derived from thawed bipronuclear oocytes. CONCLUSION(S): Birth weights are lower in cycles with fresh blastocyst transfer after controlled ovarian stimulation than in transfers of frozen-thawed embryos in the absence of ovarian stimulation. This finding confirms similar results reported in many retrospective studies. CLINICAL TRIAL REGISTRATION NUMBERS: NCT00963625 and NCT00963079.
Authors: Julia F Litzky; Sheree L Boulet; Navid Esfandiari; Yujia Zhang; Dmitry M Kissin; Regan N Theiler; Carmen J Marsit Journal: Am J Obstet Gynecol Date: 2017-12-29 Impact factor: 8.661