Liesbeth Lewi

The outcome of monochorionic diamniotic twin gestations in the era of invasive fetal therapy: a prospective cohort study

OBJECTIVE The purpose of this study was to document pregnancy and neonatal outcome of monochorionic diamniotic twin pregnancies. STUDY DESIGN This observational study describes a prospective series included in the first trimester in 2 centers of the Eurotwin2twin project. RESULTS Of the 202 included twin pairs, 172 (85%) resulted in 2 survivors, 15 (7.5%) in 1 survivor, and 15 (7.5%) in no survivors. The mortality was 45 of 404 (11%), and 36 of 45 (80%) were fetal losses of 24 weeks or less, 5 of 45 (11%) between 24 weeks and birth, and 4 of 45 (9%) were neonatal deaths. Twin-to-twin transfusion syndrome (TTTS) occurred in 18 of 202 (9%). The mortality of TTTS was 20 of 36 (55%), which accounted for 20 of 45 (44%) of all losses. Severe discordant growth without TTTS occurred in 29 of 202 (14%). Its mortality was 5 of 58 (9%), which accounted for 5 of 45 (11%) of all losses. Major discordant congenital anomalies occurred in 12 of 202 (6%). Of the 178 pairs that continued after 24 weeks, 10 (6%) had severe hemoglobin differences at birth. After 32 weeks, the prospective risk of intrauterine demise was 2 in 161 pregnancies (1.2%; 95% confidence interval, 0.3-4.6). CONCLUSION Of the monochorionic twins recruited in the first trimester, 85% resulted in the survival of both twins, and 92.5% resulted in the survival of at least 1 twin. Most losses were at 24 weeks or less, and TTTS was the most important cause of death. After 32 weeks, the risk of intrauterine demise appears to be small.

A classification system for selective intrauterine growth restriction in monochorionic pregnancies according to umbilical artery Doppler flow in the smaller twin

To evaluate a classification of selective intrauterine growth restriction (sIUGR) in monochorionic (MC) twins based on the characteristics of umbilical artery (UA) Doppler flow in the smaller twin, in terms of association with clinical outcome and with the pattern of placental anastomoses.

Prevalence of neurological damage in monochorionic twins with selective intrauterine growth restriction and intermittent absent or reversed end-diastolic umbilical artery flow

To assess the incidence of parenchymal lesions on early and late neonatal brain scans and its association with the presence or absence of intermittent absent or reversed end‐diastolic umbilical artery flow velocity (A/REDV) in monochorionic twins complicated by selective intrauterine growth restriction (IUGR), as compared to dichorionic twins and monochorionic twins without selective IUGR.

Fetoscopic laser coagulation of the vascular equator versus selective coagulation for twin-to-twin transfusion syndrome: an open-label randomised controlled trial

BACKGROUND Monochorionic twin pregnancies complicated by twin-to-twin transfusion syndrome are typically treated with fetoscopic laser coagulation. Postoperative complications can occur due to residual vascular anastomoses on the placenta. We aimed to assess the efficacy and safety of a novel surgery technique that uses laser coagulation of the entire vascular equator (Solomon technique). METHODS We undertook an open-label, international, multicentre, randomised controlled trial at five European tertiary referral centres. Women with twin-to-twin transfusion syndrome were randomly assigned by online randomisation (1:1) with permuted blocks to the Solomon technique or standard laser coagulation. The primary outcome was a composite of incidence of twin anaemia polycythaemia sequence, recurrence of twin-to-twin transfusion syndrome, perinatal mortality, or severe neonatal morbidity. Analyses were by intention to treat, with results expressed as odds ratios (ORs) and 95% CIs. This trial is registered with the Dutch Trial Registry, number NTR1245. FINDINGS Between March 11, 2008, and July 12, 2012, 274 women were randomly assigned to either the Solomon group (n=139) or the standard treatment group (n=135). The primary outcome occurred in 94 (34%) of 274 fetuses in the Solomon group versus 133 (49%) of 270 in the standard treatment group (OR 0·54; 95% CI 0·35-0·82). The Solomon technique was associated with a reduction in twin anaemia polycythaemia sequence (3% vs 16% for the standard treatment; OR 0·16, 95% CI 0·05-0·49) and recurrence of twin-to-twin transfusion syndrome (1% vs 7%; 0·21, 0·04-0·98). Perinatal mortality and severe neonatal morbidity did not differ significantly between the two groups. Outside of the common and well-known complications of twin-to-twin transfusion syndrome and its treatment, no serious adverse events occurred. INTERPRETATION Fetoscopic laser coagulation of the entire vascular equator reduces postoperative fetal morbidity in severe twin-to-twin transfusion syndrome. We recommend that fetoscopic surgeons consider adopting this strategy for treatment of women with twin-to-twin transfusion syndrome. FUNDING Netherlands Organization for the Health Research and Development (ZonMw 92003545).

Clinical outcome and placental characteristics of monochorionic diamniotic twin pairs with early-and late-onset discordant growth

OBJECTIVE The purpose of this study was to examine the clinical and placental characteristics of monochorionic diamniotic twin pregnancies with early-onset discordant growth diagnosed at 20 weeks, late-onset discordant growth diagnosed at 26 weeks or later, and concordant growth. STUDY DESIGN We studied a prospective cohort that underwent an ultrasound scan in the first trimester, at 16, 20, and 26 weeks. We excluded pregnancies complicated by twin-to-twin transfusion syndrome, miscarriage, fetal death less than 16 weeks, or severe congenital anomalies. Placental sharing and angioarchitecture were assessed by injection of each cord vessel with dyed barium sulphate. The 2 territories were delineated on an X-ray angiogram. The diameter of each intertwin anastomosis was measured on a digital photograph. RESULTS We included 178 twin pairs. Early onset discordant growth, late-onset discordant growth, and concordant growth occurred in 15, 13, and 150 pregnancies, respectively. Twin pairs with early-onset discordant growth had lower survival rates and were delivered at an earlier gestational age than pairs with late-onset discordant and concordant growth. The degree of birthweight discordance was similar in early- and late-onset discordant growth. Severe intertwin hemoglobin differences at the time of birth occurred in 0%, 38%, and 3% of pairs with early-onset discordant growth, late-onset discordant growth, and concordant growth, respectively. The placentas of pairs with early-onset discordant growth were more unequally shared and had larger arterioarterial anastomoses and a larger total anastomotic diameter as compared with placentas of pairs with late onset-discordant or concordant growth. CONCLUSION Unequal placental sharing appears to be involved in the etiology of early-onset discordant growth, whereas a late intertwin transfusion imbalance may be involved in some cases with late-onset discordant growth.

Assessment of fetal cardiac function before and after therapy for twin-to-twin transfusion syndrome

OBJECTIVE We sought to assess fetal cardiac function in monochorionic twins before and after therapy for twin-to-twin transfusion syndrome (TTTS) and compare it with control subjects. STUDY DESIGN We conducted prospective longitudinal assessment of fetal cardiac function in cases undergoing curative fetal therapy for TTTS (n = 39) until 4 weeks postoperatively and in uncomplicated monochorionic twins (n = 23). Fetal cardiac function was assessed by the left and right ventricular myocardial performance index, atrioventricular valve flow pattern, ductus venosus a-wave, and umbilical vein pulsations. RESULTS Nomograms for the myocardial performance index were constructed. Fetal cardiac function was grossly abnormal in recipient twins of TTTS when compared with control subjects (P < .001 for all indices) but normalized by 4 weeks postoperatively. The donor developed abnormal ductus venosus flow and tricuspid regurgitation postoperatively that regressed within 4 weeks. CONCLUSION The cardiac dysfunction in the recipient twin of TTTS normalizes within 1 month after laser. The donor develops a transient impairment of cardiac function postoperatively.

Twin reversed arterial perfusion: fetoscopic laser coagulation of placental anastomoses or the umbilical cord

To assess the feasibility and outcome of fetoscopic laser coagulation in pregnancies with twin reversed arterial perfusion (TRAP) sequence.

Monochorionic Diamniotic Twin Pregnancies: Natural History and Risk Stratification

About 30% of monochorionic twin pregnancies are complicated by twin-to-twin transfusion syndrome (TTTS), isolated discordant growth, twin anemia-polycythemia sequence, congenital defects or intrauterine demise. About 15% will be eligible for invasive fetal therapy, either fetoscopic laser treatment for TTTS or fetoscopic or ultrasound-guided umbilical cord coagulation for a severe congenital defect in one twin or severe discordant growth with imminent demise of the growth-restricted twin. Ultrasound examination in the first and early second trimester can differentiate the monochorionic twins at high risk for adverse outcome from those likely to be uneventful, which may be useful for patient counselling and planning of care.

The pregnancy and long-term neurodevelopmental outcome of monochorionic diamniotic twin gestations: a multicenter prospective cohort study from the first trimester onward

OBJECTIVES We sought to document the pregnancy and neurodevelopmental outcome in monochorionic diamniotic twin pregnancies and to identify risk factors for death and impairment. STUDY DESIGN We conducted a prospective cohort study of 136 monochorionic twins followed up from the first trimester until infancy. RESULTS A total of 122 (90%) pregnancies resulted in 2 survivors, 6 (4%) in 1 survivor and 8 (6%) in no survivor. In all, 230 (92%) of 250 surviving infants were assessed at a mean age of 24 months. Neurodevelopmental impairment was present in 22 (10%) infants. Death or impairment of 1 or both infants occurred in 28 (22%) of 126 pregnancies. Twin-to-twin transfusion syndrome and assisted conception increased the risk of both death and impairment, whereas early-onset discordant growth only increased the risk of death. CONCLUSION The mortality in this prospective series was 8% and neurodevelopmental impairment occurred in 10% of infants.

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