Donor catch-up growth after laser surgery for twin–twin transfusion syndrome ★★★

• After laser surgery for twin–twin transfusion syndrome (TTTS), donor twins exhibit significant catch-up growth.
• Donor growth restriction decreased from 56% at prenatal diagnosis of TTTS, to 35% at birth, and to 6% at two years of age.
• The clinical significance of the catch-up growth in the donor fetus is a ripe area for future research.

ObjectiveTo assess fetal growth after laser surgery for TTTS at the time of prenatal diagnosis, birth, and at 2 years of age.Design/methodsGrowth data were collected from surviving children treated between 2007 and 2010 as part of a study to assess neurodevelopment at 24 months (± 6 weeks) corrected age. Fetal weights were obtained via ultrasound using Hadlock's formula at the time of preoperative assessment for laser surgery. Birth weights were recorded by the staff at the delivering institutions. Weights at 2 years corrected age were recorded at the time of neurodevelopmental testing. Weights were converted into percentiles according to standard growth curves. Growth restriction was defined as < 10th percentile for given age. Multilevel latent growth curve models in Mplus (twins nested in families) examined weight change over time as a function of donor status, and repeated measures ANOVA was utilized to assess in donor–recipient weight discordance over time for twin pairs.Results99 of 206 children (56 of 130 families) were studied. There were no differences between enrolled and non-enrolled patients in donor/recipient status and survival rates, fetal demise, intrauterine growth restriction, Quintero stage, and gestational age of surgery or delivery. 48.5% were donors. The median fetal, birth, and 2-year weights for all twins were 288 g, 1.9 kg, and 11.8 kg, respectively, and the overall prevalence of growth restriction was 28%, 22%, and 3%, respectively. Growth restriction rates at prenatal diagnosis were 56% in donors vs. 2% in recipients (OR = 64.3, p < 0.001); at birth, 35% vs. 10% (OR = 5.0, p < 0.01); and at 2 years, 6% vs. 0%. Donors showed significant gains in weight percentile (B = 13.1, p < 0.001) and a significant decrease in growth restriction rates over time (B = − 1.6, p < 0.001). Weight discordance between donor and recipient pairs also significantly decreased over time (linear F(1,42) = 54.34, p < 0.001).ConclusionsAfter laser surgery for TTTS, donor twins exhibit significant catch-up growth by two years of age.