Table 2.
Sonographic characteristics by progression to TTTS
| Variable | All PART pregnancies (n = 64) |
By progression to TTTS | ||
|---|---|---|---|---|
| PART without progression to TTTS (n = 49) |
PART with progression to TTTS (n = 15) |
p-Value | ||
| DVP of polytwin, cma,b | 9.5 (2.4) | 9.2 (1.9) | 10.5 (3.3) | 0.03 |
| DVP of cotwin, cma,b | 3.5 (1.5) | 3.7 (1.3) | 3.0 (1.3) | 0.02 |
| ΔDVP, cma,b | 6.2 (2.9) | 5.4 (2.7) | 7.5 (2.1) | 0.01 |
| Anterior placenta, n (%)c | 25 (39.1) | 19 (38.8) | 6 (40.0) | >0.99 |
| Posterior placenta, n (%)c | 39 (60.9) | 30 (61.2) | 9 (60.0) | |
| EFW discordance, %a,b | 16.5 (18.0) | 20.0 (17.0) | 11.0 (8.0) | 0.05 |
| EFW discordance >20%, n (%)c | 29 (45.3) | 26 (53.1) | 3 (20.0) | 0.04 |
| FGRe of cotwin, n (%)b,c | 6 (10.5) | 6 (12.2) | 0 (0.0) | 0.32 |
| Birth weight discordance, %a,d | 19.4 (12.2) | 21.8 (12.0) | 17.1 (5.5) | 0.40 |
| AREDF of cotwin, n (%)b,c | 5 (7.8) | 4 (8.2) | 1 (6.7) | >0.99 |
| A-A anastomosis present, n (%)c | 36 (56.3) | 33 (67.4) | 3 (20.0) | <0.01 |
| Marginal or velamentous cord insertion of poly twin, n (%)c | 17 (26.6) | 13 (26.5) | 4 (26.7) | >0.99 |
| Marginal or velamentous cord insertion of cotwin, n (%)c | 39 (60.9) | 30 (61.2) | 9 (60.0) | >0.99 |
Abbreviations: A-A, arterioarterial; AREDF, absent or reversed end-diastolic flow in the umbilical artery on in utero Doppler; DVP, deepest vertical pocket; EFW, estimated fetal weight; FGR, fetal growth restriction; GA, gestational age; PART, polyhydramnios affecting a recipient-like twin; TTTS, twin–twin transfusion syndrome; ΔDVP, difference in deepest vertical pocket at diagnosis.
Note: Wilcoxon’s rank-sum and Fisher’s exact tests were used to compare nonparametric continuous variables and proportions, respectively.
p-Values correspond to comparisons between the group progressing to TTTS and the group that did not progress.
Results for continuous variables are displayed as median (interquartile range).
Results for proportions are displayed as n (percentage).
At the time of diagnosis of PART.
Excluding patients who underwent elective termination and/or dilation and curettage.
Defined as cotwin EFW ≤ 10%ile for GA at any time from diagnosis of PART to delivery.