Post-Laser Twin Anemia Polycythemia Sequence: Diagnosis, Management, and Outcome in an International Cohort of 164 Cases

Abstract

The aim of this study was to investigate the management and outcome in the post-laser twin anemia polycythemia sequence (TAPS). Data of the international TAPS Registry, collected between 2014 and 2019, were used for this study. The primary outcomes were perinatal mortality and severe neonatal morbidity. Secondary outcomes included a risk factor analysis for perinatal mortality and severe neonatal morbidity. A total of 164 post-laser TAPS pregnancies were included, of which 92% (151/164) were diagnosed antenatally and 8% (13/164) postnatally. The median number of days between laser for TTTS and detection of TAPS was 14 (IQR: 7–28, range: 1–119). Antenatal management included expectant management in 43% (62/151), intrauterine transfusion with or without partial exchange transfusion in 29% (44/151), repeated laser surgery in 15% (24/151), selective feticide in 7% (11/151), delivery in 6% (9/151), and termination of pregnancy in 1% (1/151). The median gestational age (GA) at birth was 31.7 weeks (IQR: 28.6–33.7; range: 19.0–41.3). The perinatal mortality rate was 25% (83/327) for the total group, 37% (61/164) for donors, and 14% (22/163) for recipients (p < 0.001). Severe neonatal morbidity was detected in 40% (105/263) of the cohort and was similar for donors (43%; 51/118) and recipients (37%; 54/145), p = 0.568. Independent risk factors for spontaneous perinatal mortality were antenatal TAPS Stage 4 (OR = 3.4, 95%CI 1.4-26.0, p = 0.015), TAPS donor status (OR = 4.2, 95%CI 2.1–8.3, p < 0.001), and GA at birth (OR = 0.8, 95%CI 0.7–0.9, p = 0.001). Severe neonatal morbidity was significantly associated with GA at birth (OR = 1.5, 95%CI 1.3–1.7, p < 0.001). In conclusion, post-laser TAPS most often occurs within one month after laser for TTTS, but may develop up to 17 weeks after initial surgery. Management is mostly expectant, but varies greatly, highlighting the lack of consensus on the optimal treatment and heterogeneity of the condition. Perinatal outcome is poor, particularly due to the high rate of perinatal mortality in donor twins.

Treatment and outcome of 370 cases with spontaneous or post‐laser twin anemia–polycythemia sequence managed in 17 fetal therapy centers

“…missed antenatally) and/or if they were diagnosed with post-laser TAPS within 1 week after laser for TTTS, unless TAPS persisted after 1 week, and/or if they were first diagnosed with TAPS at Stage 5. The outcomes of TAPS cases diagnosed postnatally are presented in two 380 Tollenaar et al other studies investigating perinatal outcome separately in spontaneous and post-laser TAPS 10,11 .…”

“…Severe perinatal morbidity rates were high in all groups, but were significantly increased in cases treated with IUT (± PET) or delivery within 7 days after diagnosis. Notably, TAPS twins managed with IUT (± PET) were delivered at a significantly earlier gestation compared with all other management groups, which is known to have significant impact on short-term outcome 10,11 . However, twins managed with delivery were born at a comparable gestational age to that of twins treated with laser surgery, which suggests that other factors might play a role.…”

“…However, laser surgery was associated with a high diagnosis-to-birth interval, especially in comparison to treatment with IUT (± PET). As prematurity has a profound impact on short-and long-term health in TAPS twins, prolongation of pregnancy is of the utmost importance to improve outcome 6,7,10,11 . Notably, a comparable prolongation of pregnancy was achieved with selective feticide and expectant management.…”

“…On the other hand, in expectant management, prolongation of pregnancy likely results in continuous exposure to the potential detrimental effects of TAPS, as only 16% of cases showed spontaneous resolution. As risk for perinatal mortality and morbidity increases with increasing antenatal TAPS stage, definitive treatment with laser might be the optimal intervention to improve perinatal outcome for this condition 11,24 .…”

“…The management groups differed in terms of GA at diagnosis, severity of TAPS and type of TAPS. Since higher TAPS stage and post-laser TAPS are associated with poorer prognosis, these factors could have influenced significantly the perinatal outcome 10,11 . Moreover, long-term outcome was not investigated in this study.…”