F.P.H.A. Vandenbussche

Twin Anemia-Polycythemia Sequence: Diagnostic Criteria, Classification, Perinatal Management and Outcome

Monochorionic twins share a single placenta with intertwin vascular anastomoses, allowing the transfer of blood from one fetus to the other and vice versa. These anastomoses are the essential anatomical substrate for the development of several complications, including twin-twin transfusion syndrome (TTTS) and twin anemia-polycythemia sequence (TAPS). TTTS and TAPS are both chronic forms of fetofetal transfusion. TTTS is characterized by the twin oligopolyhydramnios sequence, whereas TAPS is characterized by large intertwin hemoglobin differences in the absence of amniotic fluid discordances. TAPS may occur spontaneously in up to 5% of monochorionic twins and may also develop after incomplete laser treatment in TTTS cases. This review focuses on the pathogenesis, incidence, diagnostic criteria, management options and outcome in TAPS. In addition, we propose a classification system for antenatal and postnatal TAPS.

Long-term neurodevelopmental outcome in twin-to-twin transfusion syndrome

OBJECTIVEnThe purpose of this study was to determine the long-term neurodevelopmental outcome in children after twin-to-twin transfusion syndrome.nnnSTUDY DESIGNnMaternal and neonatal medical records of all twin-to-twin transfusion syndrome patients who were admitted to our center between 1990 and 1998 were reviewed. Neurologic and mental development at school age was assessed during a home visit in all twin-to-twin transfusion syndrome survivors.nnnRESULTSnA total of 33 pregnancies with twin-to-twin transfusion syndrome were identified. Four couples opted for termination of pregnancy. All other pregnancies were treated conservatively, 18 pregnancies (62%) with serial amnioreductions and 11 pregnancies (38%) without intrauterine interventions. Mean gestational age at delivery was 28.6 weeks (range, 20-37 weeks). The perinatal mortality rate was 50% (29/58 infants). The birth weight of the donor twins was less than the recipient twins (P<.001). Systolic blood pressure at birth was lower in donors than in recipients (P=.023), and donors required inotropic support postnatally more frequently than did recipients (P=.008). The incidence of hypertension at birth was higher in recipients than in donors (P=.038). Abnormal cranial ultrasonographic findings were reported in 41% of the neonates (12/29 neonates). All long-term survivors (n=29 neonates) were assessed during a home visit. Mean gestational age at birth of the surviving twin was 31.6 weeks (range, 25-37 weeks). The mean age at follow-up was 6.2 years (range, 4-11 years). The incidence of cerebral palsy was 21% (6/29 infants). Five of 6 children with cerebral palsy had an abnormal mental development. The incidence of cerebral palsy in the group of survivors who were treated with serial amnioreduction was 26% (5/19 infants). Four children were born after the intrauterine fetal demise of their co-twin, 2 of which had cerebral palsy.nnnCONCLUSIONnThe incidence of adverse neurodevelopmental outcome in twin-to-twin transfusion syndrome survivors is high, especially after the intrauterine fetal demise of a co-twin.

Placental characteristics in monochorionic twins with and without twin anemia-polycythemia sequence.

OBJECTIVE: To study the placental angioarchitecture of monochorionic placentas with and without twin anemia–polycythemia sequence. METHODS: Eligible were all placentas from monochorionic twin gestations, not complicated by twin-to-twin transfusion syndrome and resulting in double survival. The study was conducted at two European Fetal Therapy Centers between 2002 and 2008. Placental angioarchitecture was evaluated using colored dye injection. Diagnosis of twin anemia–polycythemia sequence was based on the presence of large intertwin hemoglobin difference without the degree of amniotic fluid discordance that is required for the diagnosis of twin transfusion syndrome. RESULTS: Three-hundred thirteen monochorionic twin pregnancies were eligible for the study but placental data could not be completed for 62 placentas (20%). This left 251 monochorionic twin pregnancies of which 11 (4%) fulfilled the criteria for twin anemia–polycythemia sequence. The median number of anastomoses in monochorionic placentas with and without twin anemia–polycythemia sequence was 3 (range: 2–5) and 7 (range: 0–25), respectively (P<.001). Small anastomoses were present in 91% (10/11) of twin anemia–polycythemia sequence-placentas compared with 5% (12/240) of cases without twin anemia–polycythemia sequence (P<.001). Arterioarterial anastomoses were absent in twin anemia–polycythemia sequence-placentas and present in 89% (213/240) of placentas without twin anemia–polycythemia sequence (P<.001). CONCLUSION: Monochorionic twin placentas with twin anemia–polycythemia sequence are characterized by a paucity of anastomoses and the absence of arterioarterial anastomoses. The few anastomoses that are present in twin anemia–polycythemia sequence placentas are mostly small arteriovenous anastomoses. LEVEL OF EVIDENCE: II

Benefits and risks of fetal red-cell transfusion after 32 weeks gestation

OBJECTIVEnTo compare the outcome after intrauterine transfusion (IUT) between fetuses treated before and those treated after 32 weeks gestation.nnnSETTINGnNational referral center for intrauterine treatment of red-cell alloimmunization in The Netherlands.nnnSTUDY DESIGNnRetrospective evaluation of an 11 year period, during which 209 fetuses were treated for alloimmune hemolytic disease with 609 red-cell IUTs. We compared fetal and neonatal outcome in three groups: fetuses only treated before 32 weeks gestation (group A, n=46), those treated both before and after 32 weeks (group B, n=117), and those where IUT was started at or after 32 weeks (group C, n=46).nnnRESULTSnSurvival rate was 48% in group A, 100% in group B, and 91% in group C. Moreover, fetuses in group A were hydropic significantly more often. Short-term perinatal loss rate after IUT was 3.4% in the 409 procedures performed before 32 weeks and 1.0% in the 200 procedures performed after 32 weeks gestation.nnnCONCLUSIONnPerinatal losses were much more common in fetuses only treated before 32 weeks gestation. Two procedure-related perinatal losses in 200 IUT after 32 weeks remain a matter of concern because of the good prospects of alternative extrauterine treatment.

Non-invasive tests to predict fetal anemia in Kell-alloimmunized pregnancies

To compare test characteristics of ultrasound and Doppler parameters in the prediction of fetal anemia in Kell‐alloimmunized pregnancies.

Placental Characteristics of Monoamniotic Twin Pregnancies in Relation to Perinatal Outcome

OBJECTIVEnTo study placental characteristics in relation to perinatal outcome in 55 pairs of monochorionic monoamniotic (MA) twins.nnnMETHODSnBetween January 1998 and May 2008 55 pairs of MA twins were delivered in 4 tertiary care centers and analysed for mortality, birth weight discordancy and twin-to-twin transfusion syndrome (TTTS) in relation to type of anastomoses, type and distance between cord insertions and placental sharing. Five acardiac twins, 2 conjoined twins, 4 higher order multiples and one early termination of pregnancy were excluded, leaving 43 MA placentas for analysis. Of these 43, one placenta could not be analysed for placental vascular anastomoses due to severe maceration after single intra-uterine demise leaving 42 placentas for analysis of anastomoses.nnnRESULTSnArterio-arterial (AA), venovenous (VV) and arteriovenous (AV) anastomoses were detected in 98%, 43% and 91% of MA placentas, respectively. Velamentous cord insertion was found in 4% of cases. Small distance between both umbilical cord insertions (<5 cm) was present in 53% of MA placentas. Overall perinatal loss rate was 22% (19/86). We found no association between mortality and type of anastomoses, type and distance between cord insertions and placental sharing. The incidence of TTTS was low (2%) and occurred in the only pregnancy with absent AA-anastomoses.nnnCONCLUSIONnPerinatal mortality in MA twins was not related to placental vascular anatomy. The almost ubiquitous presence of compensating AA-anastomoses in MA placentas appears to prevent occurrence of TTTS.

Short- and long-term outcome in stage 1 twin-to-twin transfusion syndrome treated with laser surgery compared with conservative management.

OBJECTIVEnWe sought to compare short- and long-term outcome in Quintero stage 1 twin-to-twin transfusion syndrome (TTTS), managed with laser surgery or conservatively.nnnSTUDY DESIGNnWe conducted a retrospective study of all monochorionic twin pregnancies with stage 1 TTTS referred to our center. Primary outcomes were perinatal survival, neonatal morbidity, and long-term neurodevelopmental outcome.nnnRESULTSnFifty women presented with stage 1 TTTS of which 40% (20/50) was treated with laser and 60% (30/50) was managed conservatively. Perinatal survival of both or at least 1 twin was 65% (13/20) and 85% (17/20) in the laser group, and 77% (23/30) and 97% (29/30) in the conservatively managed group (P = .52 and P = .29), respectively. Long-term neurodevelopmental impairment of the surviving infants was found in 0% (0/21) vs 23% (7/30), respectively (P = .03).nnnCONCLUSIONnIn this retrospective study, long-term outcome in stage 1 TTTS was better after laser surgery than with conservative management, suggesting the need for a randomized controlled trial.

Congenital heart disease in twin-to-twin transfusion syndrome treated with fetoscopic laser surgery.

OBJECTIVEnTo determine the incidence of congenital heart disease (CHD) and right ventricular outflow tract obstruction (RVOTO) in twin-to-twin transfusion syndrome (TTTS) treated with fetoscopic laser surgery and evaluate the role of increased afterload by determining the difference in blood pressure and endothelin-1 at birth between donor and recipient twins.nnnDESIGNnProspective study.nnnSETTINGnTertiary medical center, serving as the national referral center for fetoscopic laser surgery for TTTS in The Netherlands.nnnPATIENTSnAll consecutive cases of monochorionic twins with TTTS treated with laser (n = 46 twin pairs) and monochorionic twins without TTTS (n = 55 twin pairs) delivered at our center between June 2002 and June 2005 were included in the study.nnnINTERVENTIONSnEchocardiography was performed within 1 week after delivery. At birth, blood pressure was measured in all survivors and endothelin-1 was determined in umbilical cord blood. Data on RVOTO in TTTS treated with laser surgery at our center but delivered elsewhere were reviewed retrospectively from medical records.nnnRESULTSnThe incidence of CHD in the TTTS group and non-TTTS group was 5.4% (4/74) and 2.3% (2/87) (P = .42), respectively. RVOTO was diagnosed in 1 recipient twin delivered at our center and 2 recipient twins delivered elsewhere. The incidence of RVOTO in recipients was 4% (3/75). Mean systolic blood pressure at birth was similar in donor and recipient twins, respectively, 53 mm Hg vs. 56 mm Hg (P = .42). Mean endothelin-1 level at birth was also similar between donors and recipients, respectively, 14.3 ng/L and 13.2 ng/L (P = .64).nnnCONCLUSIONnThe incidence of CHD in TTTS treated with fetoscopic laser surgery is higher than in the general population (5.4% vs. 0.5%). We found no difference in afterload parameters between donors and recipients after laser treatment.

In utero acquired limb ischemia in monochorionic twins with and without twin‐to‐twin transfusion syndrome

To report on the occurrence of in utero acquired limb ischemia in two referral institutions managing monochorionic (MC) twins with and without twin‐to‐twin transfusion syndrome (TTTS) and estimate its prevalence.

Quality Control for Intravascular Intrauterine Transfusion Using Cumulative Sum (CUSUM) Analysis for the Monitoring of Individual Performance

Introduction: Intravascular intrauterine transfusion (IUT) is an effective and relatively safe method for the treatment of fetal anemia. Although implemented in centers all over the world in the 1980s, the length and strength of the learning curve for this procedure has never been studied. Cumulative sum (CUSUM) analysis has been increasingly used as a graphical and statistical tool for quality control and learning curve assessment in clinical medicine. We aimed to test the feasibility of CUSUM analysis for quality control in fetal therapy by using this method to monitor individual performance of IUT in the learning phase and over the long term. Methods: IUTs performed in the Dutch referral center for fetal therapy from 1987 to 2009 were retrospectively classified as successful or failed. Failed was defined as no net transfusion or the occurrence of life-threatening procedure-related complications. The CUSUM statistical method was used to estimate individual learning curves and to monitor long-term performance. Four operators who each performed at least 200 procedures were included. Results: Individual CUSUM graphs were easily assessed. Both operators pioneering IUT in the late 1980s had long learning phases. The 2 operators learning IUT in later years in an experienced team performed acceptably from the start and reached a level of competence after 34 and 49 procedures. Discussion: CUSUM analysis is a feasible method for quality control in fetal therapy. In an experienced setting, individual competence may be reached after 30 to 50 IUTs. Our data suggest that operators need at least 10 procedures per year to keep a level of competence.