title: IVF culture medium affects post-natal weight in humans during the first 2 years of life.
abstract: OBJECTIVE
  Is post-natal growth during the first 2 years of life in IVF singletons affected by type of medium used for culturing human embryos during an IVF treatment?
  
  
  CONCLUSIONS
  The in vitro culture of human embryos in medium from Cook resulted in singletons with a lower weight during the first 2 years of life compared with singletons born after embryo culture in medium from Vitrolife.
  
  
  BACKGROUND
  In a previous study, we reported that type of medium used for culturing human IVF embryos during the first few days after fertilization until fresh embryo transfer significantly affects fetal growth and consequently birthweight of the resulting singletons.
  
  
  METHODS
  From July 2003 to December 2006, a total of 1432 IVF treatment cycles with fresh embryo transfer were randomly allocated to have all embryos cultured in medium from Vitrolife AB (n = 715) or from Cook (n = 717). Two years after delivery, questionnaires were sent to the parents of all children requesting data about weight, height and head circumference around 1, 2, 3, 4, 6, 7.5, 9, 11, 14, 18 and 24 months of age. These measurements were collected as part of the children's health programme at municipal infant welfare centres in the Netherlands by health professionals unaware of this study.
  
  
  METHODS
  Patients requiring donor oocytes or applying for PGD were excluded from the study. From the 294 live born singletons that fulfilled our inclusion criteria, 29 were lost to follow-up. The remaining 265 singletons (Cook group: 117, Vitrolife group: 148) were included in the analysis. Data analysis included linear regression, to compare cross-sectionally weight standard deviation score (SDS), height SDS and head circumference, and the first order Berkey-Reed model for a longitudinal analysis of the growth data.
  
  
  RESULTS
  Singletons in the Vitrolife group were heavier during the first 2 years of life compared with singletons in the Cook group. Cross-sectional analyses showed that adjusted weight SDS differed between groups at 1 (0.35 ± 0.14, P = 0.010), 2 (0.39 ± 0.14, P = 0.006), 3 (0.35 ± 0.14, P = 0.011), 4 (0.30 ± 0.13, P = 0.020), 11 (0.28 ± 0.13, P = 0.036), 14 (0.32 ± 0.13, P = 0.014) and 24 (0.39 ± 0.15, P = 0.011) months of age, while adjusted height SDS was only significantly different at 1 (0.21 ± 0.11, P = 0.048) month of age. Head circumference was similar between the two groups at all ages. Longitudinal analyses showed that both post-natal weight (P = 0.005) and height (P = 0.031) differed between the groups throughout the first 2 years of life, while the growth velocity was not significantly different between the two groups.
  
  
  CONCLUSIONS
  Factors that might influence post-natal growth were included in the analysis; however, it was not possible to include all such factors, for example childhood diseases or nutrition, as this information was not available.
  
  
  CONCLUSIONS
  The effect of culture medium during the first few days after fertilization on prenatal growth and birthweight persists during the first 2 years of life. This suggests that the human embryo is sensitive to its very early environment, and that the culture medium used in IVF may have lasting consequences. Further monitoring of the long-term growth, development and health of IVF children is therefore warranted.
  
  
  BACKGROUND
  W.V. was funded with an unrestricted research grant from the Stichting Fertility Foundation. The authors declare no conflict of interest.
  
  
  BACKGROUND
  Not applicable.
authors.affiliation: Department of Obstetrics & Gynaecology, GROW School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Sander H M
authors.initials: SH
authors.lastname: Kleijkers
authors.forename: Aafke P A
authors.initials: AP
authors.lastname: van Montfoort
authors.forename: Luc J M
authors.initials: LJ
authors.lastname: Smits
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Viechtbauer
authors.forename: Tessa J
authors.initials: TJ
authors.lastname: Roseboom
authors.forename: Ewka C M
authors.initials: EC
authors.lastname: Nelissen
authors.forename: Edith
authors.initials: E
authors.lastname: Coonen
authors.forename: Josien G
authors.initials: JG
authors.lastname: Derhaag
authors.forename: Lobke
authors.initials: L
authors.lastname: Bastings
authors.forename: Inge E L
authors.initials: IE
authors.lastname: Schreurs
authors.forename: Johannes L H
authors.initials: JL
authors.lastname: Evers
authors.forename: John C M
authors.initials: JC
authors.lastname: Dumoulin
mesh_terms: D001827:Body Height / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects*; D002657:Child Development / Q000187:drug effects*; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003470:Culture Media / Q000494:pharmacology*; D046149:Embryo Culture Techniques; D005307:Fertilization in Vitro; D047109:Fetal Development; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008137:Longitudinal Studies
chemical_list: D003470:Culture Media
keywords: ICSI; IVF; culture medium; human; post-natal growth