(1154) Predictors of poor outcomes in monochorionic diamniotic twin pregnancies complicated by selective fetal growth restriction

Monochorionic diamniotic (MCDA) twin pregnancies with selective fetal growth restriction (sFGR) are at high risk for fetal loss. The objective was to identify predictors of poor outcomes in sFGR pregnancies irrespective of the umbilical artery (UA) Doppler abnormalities.

Study Design:

Retrospective analysis of MCDA twin pregnancies diagnosed with sFGR that opted for expectant management between 2010-2021. Patients were assessed for the presence of one or more of the following in the growth restricted fetus: low amniotic fluid volume (DVP < 2cm), lack of a cycling bladder, absent or reversed flow in ductus venosus (DV) with atrial contraction and elevated middle cerebral artery peak systolic velocity (MCA-PSV). Presence of each variable in the growth restricted twin was given a score of 1. Cases were classified as simple if the cumulative score was 0 and complicated if the cumulative score was 1-4.  The groups were then compared using Mann-Whitney U test for continuous variables and Fisher’s exact test for categorical variables. The score was compared with the outcome of two survivors to discharge using logistic regression. 

Results:

Of 131 pregnancies, 83 (62.6%) were simple and 49 (37.4%) were complicated. UA Doppler abnormalities and type of sFGR were similar in both groups. Intertwin EFW discordance was higher in the complicated category. Amniotic fluid and EFW in donor were lower in the complicated group. Median gestational age at delivery was earlier and the likelihood of survival was lower in the complicated category.  On the logistic regression, an increase in score negatively correlated with the outcome of two survivors to discharge (p < 0.0001). ROC curve was created, and the AUC was 0.9.

Conclusion:

Presence of additional findings in the growth restricted twin; specifically oligohydramnios, lack of cycling bladder, abnormal DV waveform, and elevated MCA-PSV; irrespective of the umbilical artery Dopplers is associated with earlier gestational age at delivery and higher risk for perinatal loss.  An assigned score based on the presence of these variables can help predict survival in these cases.