title: Sex ratio and birth weights of infants born as a result of blastocyst transfers compared with early cleavage stage embryo transfers.
abstract: OBJECTIVE
  To analyze the birth weights and sex ratio of infants born as a result of blastocyst transfer and compare them with data resulting from the transfer of early-cleavage stage embryos.
  
  
  METHODS
  Retrospective analysis.
  
  
  METHODS
  Monash IVF (private in vitro fertilization clinic).
  
  
  METHODS
  One hundred twenty-five infertile patients who became pregnant after IVF procedures involving blastocyst transfer.
  
  
  METHODS
  None.
  
  
  METHODS
  Sex ratio and birth weights of infants born after blastocyst transfer.
  
  
  RESULTS
  The sex ratio of 129.6 for infants born after blastocyst transfer was not significantly different from the sex ratio calculated from data compiled by NPSU for births resulting from early cleavage stage embryo transfers at Monash IVF (100.6) and all other assisted conception units in Australia and New Zealand (97.9). No differences were observed in the combined mean birth weight of male and female infants born as a result of blastocyst transfers and early-cleavage stage embryo transfers.
  
  
  CONCLUSIONS
  There is no evidence of abnormal fetal growth or a shift in the sex ratio for infants born as a result of blastocyst transfer when compared with the case of births resulting from early cleavage stage embryo transfers within our unit or all other assisted conception units in Australia and New Zealand.
authors.affiliation: Centre for Early Human Development, Monash Institute of Reproduction and Development, Melbourne, Victoria, Australia.
authors.forename: A
authors.initials: A
authors.lastname: Kausche
authors.forename: G M
authors.initials: GM
authors.lastname: Jones
authors.forename: A O
authors.initials: AO
authors.lastname: Trounson
authors.forename: F
authors.initials: F
authors.lastname: Figueiredo
authors.forename: V
authors.initials: V
authors.lastname: MacLachlan
authors.forename: N
authors.initials: N
authors.lastname: Lolatgis
mesh_terms: D001724:Birth Weight; D002970:Cleavage Stage, Ovum; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D012189:Retrospective Studies; D012744:Sex Ratio