Tonch, N.

children study singleton health ivf twins outcome ivf singletons embryo transfer embryo transfer pregnancy sample netherland strategy health problems health outcomes birth centre reprod data collection problem cost-effectiveness hospital embryo transfer strategies model result analysis maastricht university university parent collection department information det strategies twinsing study patient treatment van heesch ivf treatment base sample pediatrics 18- year maastricht twinsing child heesch birth weight complication number category evers jl markov model perinatal outcome data health status figure research measure hemminki e cycle value land ja weight outcome measure mother cohort development radboud university nijmegen family pinborg fertilization dutch rotterdam pregnancy rates apgar score resource use ivf children expert opinion quality twinsing model