Participants were singletons born following controlled ovarian hyperstimulation-IVF/ICSI (COH-IVF/ICSI; n = 66), or modified natural cycle-IVF/ICSI (MNC-IVF/ICSI; n = 56), or to subfertile couples who conceived naturally (Sub-NC; n = 86). Dysmorphic features were assessed according to the method of Merks et al., and are classified into ¡®minor variants¡¯ (minor anomalies or common variants) and ¡®abnormalities¡¯ (clinically relevant or irrelevant abnormalities). We focussed on minor anomalies as they indicate altered embryonic development and because they have the advantage of a higher prevalence.
The prevalences of any of the outcome measures were similar in the three groups. One or more minor anomalies, our primary outcome measure, occurred in 50 % of COH-IVF/ICSI, 54 % of MNC-IVF/ICSI and 53 % of Sub-NC children. TTP in years was significantly associated with abnormalities (adjustedOR = 1.20; 95 % CI = 1.02-1.40), especially with clinically relevant abnormalities (adjustedOR = 1.22; 95 % CI = 1.01-1.48).
The study indicates that ovarian hyperstimulation and the in vitro procedure are not associated with an increase in dysmorphic features. The positive association between TTP and clinically relevant abnormalities suggests a role of the underlying subfertility and its determinants in the genesis of dysmorphic features.