Phenotypic differences in children conceived from fresh and thawed embryos in in vitro fertilization compared with naturally conceived children.

OBJECTIVE

To determine whether anthropometric and biochemical features differ in in vitro fertilization (IVF) children conceived via fresh (IVFF) or thawed (IVFT) embryo transfer compared with naturally conceived controls.

DESIGN

A cross-sectional controlled study.

SETTING

University clinical research unit.

PATIENT(S): Healthy prepubertal children (3.5-11.0 years), singletons, born at term (>37 weeks), who were either naturally conceived (controls; n = 94) or IVF children conceived via the transfer of a fresh (IVFF; n = 72) or thawed (IVFT; n = 43) embryo.

INTERVENTION(S): None.

MAIN OUTCOME MEASURE(S): Assessments of anthropometry (adjusted for parental variables), dual-energy X-ray absorptiometry-derived body composition, fasting plasma growth factors, lipids, and parameters of glucose regulation.

RESULT(S): The IVFF but not the IVFT children weighed less at birth than the control children. The IVFF children were taller than both the controls and IVFT children. Sex-specific analyses showed height differences among girls, with IVFF girls being taller than their control and IVFT counterparts. Taller stature in IVFF children was associated with increased insulin-like growth factor I (IGF-I) concentrations compared with controls, whereas the IVFT children displayed increased IGF-II and decreased insulin-like growth factor binding protein 3 (IGFBP-3) concentrations compared with the controls. More favorable lipid profiles were also evident in IVFF but not IVFT children compared with the control children.

CONCLUSION(S): These preliminary findings highlight that the transfer of a fresh versus a thawed IVF embryo affects height, plasma growth factor, and lipid profiles in childhood. Therefore, embryo derivation should be considered when assessing physical and biochemical phenotype of IVF children.