Ocular Growth and Refractive Status Development in Premature Infants Conceived by In Vitro Fertilization or Natural Conception

Background: To evaluate the effects of IVF on the development of the refractive system in premature infants from 36 weeks to 6 months of postmenstrual age. Methods: Premature infants were examined respectively at 36 weeks, 40 weeks, 44 weeks, 48 weeks, 52 weeks and 6 months of postmenstrual age. Spherical equivalent, biometric values and central corneal thickness were measured. These parameters were compared between premature infants conceived by IVF or naturally, and the relationship between these parameters were evaluated. Results: A total of 899 premature infants were recruited. Infants born by IVF had a higher rate of oxygen therapy than which in the NC group (P = 0.04). The multiple pregnancy ratio in the IVF group was 83.4%, significantly higher than which in the NC group (p<0.001). ROP developed in 126 of the 754 infants (16.7%) in the NC group and in 35 of the 145 (24.1%) infants in the IVF group (p=0.03). With the increase of PA, the ACD (r=0.67, p<0.0001), LT (r=0.19, p<0.0001), VT (r=0.80, p<0.0001) and AL (r=0.85, p<0.0001) increased while CCT (r=-0.39, p<0.0001) thinned. The refractive state had a hyperopic shift until 44 weeks of postmenstrual age (r=0.38, p<0.0001). then the mean dioptric value continuously declined by 6 months of PA (r=-0.32, p0.05). The percentage of ACD (r=0.326, p<0.0001) and VT (r=0.248, p<0.0001) in AL were positively correlated with PA, while the percentage of LT (r=-0.415, p<0.0001) in AL was negatively correlated with PA. Before 44 weeks of PA, SE was positively correlated with ACD (r=0.08, p<0.01) and AL (r=0.09, p<0.01). After 44 weeks of PA, it was negatively correlated with ACD (r=-0.23, p<0.0001), VT (r=-0.35, p<0.0001) and AL (r=-0.41, p<0.01). Conclusions: The percentage of ACD and VT in AL increased, the percentage of LT in AL decreased with the early ocular development. IVF does not affect ocular growth from 36 weeks to 6 months of PA.