Effects of selective feticide by radiofrequency ablation and risk factors for prognosis in 75 twins complicated by selective intrauterine growth restriction / 中华围产医学杂志

ABSTRACT

Objective:To analyze the effects of selective feticide by radiofrequency ablation (RFA) and the risk factors for adverse pregnancy outcomes in twins complicated by selective intrauterine growth restriction (sIUGR) and evaluate the neurodevelopment in live births during a short-term follow-up.Methods:This study retrospectively enrolled 75 twins with sIUGR who underwent RFA for selective feticide and were delivered in the First Affiliated Hospital of Sun Yat-sen University between January 1, 2017 and March 31, 2022. According to the gestational age at the procedure, they were divided into three groups including 16-19 +6 weeks of gestation (Group A, n=16), 20-23 +6 weeks of gestation (Group B, n=44) and ≥24 weeks of gestation (Group C, n=15). They were also grouped according to the presence or absence of twin-twin transfusion syndrome (TTTS) sIUGR with TTTS group ( n=36) and isolated sIUGR group ( n=39). The 39 cases in the isolated sIUGR group were further divided into three groups according to the Doppler flow in the smaller co-twin type Ⅰ ( n=3), type Ⅱ ( n=27) and type Ⅲ ( n=9). According to pregnancy outcomes, the 75 cases were divided into adverse pregnancy outcome group ( n=49) and non-adverse pregnancy outcome group ( n=26). Statistical analysis was performed using two independent sample t-test, one-way analysis of variance and LSD test, nonparametric test and Nemenyi test, as well as Chi-square test and Fisher's exact test to compare the difference in clinical characteristics and perinatal outcomes among groups. Kaplan-Meier survival curves and Log-rank test were used to analyze the duration of pregnancy after the procedure. Univariate logistic regression analysis was used to identify the risk factors for adverse pregnancy outcomes. Results:(1) The gestational age at the time of procedure was (21.9±2.3) weeks (16.6-26.0 weeks) for all cases. The intertwin estimated fetal weight discordance (&Delta;EFW) was less and the duration of RFA was shorter in group A than in group B or C [(27.8±8.4)% vs (36.2±12.0)% and (39.8±15.5)%; 7 min (5-14 min) vs 10 min (5-16 min) and 12 min (8-18 min); LSD test or Nemenyi test, P<0.017]. The incidence of TTTS was higher in group A than in group B or C [12/16 vs 43% (19/44) and 5/15; Bonferroni correction, P<0.017]. There was no significant difference in the incidence of premature rupture of membrane, spontaneous abortion, fetal demise, premature delivery and gestational age at delivery between Group A, B and C (all P>0.05). (2) Compared with the isolated sIUGR group, the sIUGR with TTTS group showed less &Delta;EFW [(29.6±11.4)% vs (40.1±11.8)%, t=3.88, P<0.001], higher incidence of premature rupture of membrane [47% (17/36) vs 21% (8/39), χ2=6.01, P=0.014], lower rate of live births [69% (25/36) vs 95%(37/39), χ2=8.45, P=0.004] and earlier delivery [34.1 weeks (26.7-40.7 weeks) vs 38.0 weeks (29.3-40.0 weeks), Z=311.50, P=0.018]. (3) There was no significant difference in the incidence of premature rupture of membrane, live birth rate or 30-day survival rate among the sIUGR type Ⅰ, Ⅱ and Ⅲ groups (all P>0.05). (4) sIUGR complicated by TTTS was a risk factor for adverse pregnancy outcomes of the co-twin after the procedure ( OR=3.94, 95% CI 1.40-11.10, P=0.010). (5) Thirteen co-twins presented with cardiac enlargement, myocardial hypertrophy or/and tricuspid regurgitation in routine ultrasound scans before the procedure and nine of them had TTTS. Among them, eight live births were followed up for one month to 4.5 years of age and no abnormality in cardiac function was reported. (6) There were overall 62 live births. Apart from two cases of neonatal death and four lost to follow-up, the other 56 cases were followed up to one month to 5 years of age and two premature infants showed gross motor retardation. Conclusions:The gestational age at RFA has no significant impact on pregnancy outcomes, while sIUGR complicated by TTTS may increase the risk of adverse outcomes after the procedure. After RFA, the overall survival rate of the co-twin in pregnancies with sIUGR is high and no severe neurodevelopmental abnormalities has been found during a short-term follow-up.