title: Higher β-HCG concentrations and higher birthweights ensue from single vitrified embryo transfers.
abstract: To examine the effect of cryopreservation on developmental potential of human embryos, this study compared quantitative β-HCG concentrations at pregnancy test after IVF-fresh embryo transfer (IVF-ET) with those arising after frozen embryo transfer (FET). It also tracked outcomes of singleton pregnancies resulting from single-embryo transfers that resulted in singleton live births (n = 869; with 417 derived from IVF-ET and 452 from FET). The initial serum β-HCG concentration indicating successful implantation was measured along with the birthweight of the ensuing infants. With testing at equivalent luteal phase lengths, the median pregnancy test β-HCG was significantly higher following FET compared with fresh IVF-ET (844.5 IU/l versus 369 IU/l; P < 0.001). Despite no significant difference in the average period of gestation (38 weeks 5 days for both groups), the mean birthweight of infants born following FET was significantly heavier by 161 g (3370 g versus 3209 g; P < 0.001). Furthermore, more infants exceeded 4000 g (P < 0.001) for FET although there was no significant difference for the macrosomic category (≥4500 g). We concluded that FET programme embryos lead to infants with equivalent (if not better) developmental potential compared with IVF-ET, demonstrated by higher pregnancy β-HCG concentrations and ensuing birthweights.
authors.affiliation: PIVET Medical Centre, Perth, Western Australia, Australia; School of Biomedical Science, Curtin Health Innovation Research Institute, Bioscience, Curtin University, Australia.
authors.forename: Kevin N
authors.initials: KN
authors.lastname: Keane
authors.affiliation: PIVET Medical Centre, Perth, Western Australia, Australia; Fertility Centre, Kulliyyah of Medicine, International Islamic University Malaysia (IIUM), Pahang, Malaysia.
authors.forename: Kamarul Bahyah
authors.initials: KB
authors.lastname: Mustafa
authors.affiliation: PIVET Medical Centre, Perth, Western Australia, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Hinchliffe
authors.affiliation: PIVET Medical Centre, Perth, Western Australia, Australia.
authors.forename: Jason
authors.initials: J
authors.lastname: Conceicao
authors.affiliation: PIVET Medical Centre, Perth, Western Australia, Australia; School of Biomedical Science, Curtin Health Innovation Research Institute, Bioscience, Curtin University, Australia. Electronic address: jlyovich@pivet.com.au.
authors.forename: John L
authors.initials: JL
authors.lastname: Yovich
mesh_terms: D000328:Adult; D001724:Birth Weight; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood*; D015925:Cryopreservation; D046149:Embryo Culture Techniques / Q000379:methods; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods; D006801:Humans; D007246:Infertility / Q000628:therapy; D008875:Middle Aged; D010060:Ovulation; D011247:Pregnancy; D011256:Pregnancy Outcome; D027724:Reproductive Techniques, Assisted; D012189:Retrospective Studies; D056826:Single Embryo Transfer; D016896:Treatment Outcome; D058989:Vitrification
chemical_list: D018997:Chorionic Gonadotropin, beta Subunit, Human
keywords: FET; IVF-ET; birthweight; single embryo transfer; vitrification; β-HCG