Twin-Twin Transfusion Syndrome

Abstract

Background-In twin-twin transfusion syndrome (TTTS), the donor and recipient fetus are exposed to differing volume loads and show discordant intertwin vascular compliance in childhood despite identical genotype. We hypothesized that discordance is prevented by intrauterine endoscopic laser ablation of placental anastomoses, which abolishes intertwin transfusion. We tested this by examining pulse wave velocity (PWV) in brachial arteries of twin survivors of TTTS treated with and without laser therapy. Methods and Results-One hundred children (50 twin pairs, 27 with TTTS) were studied. Group 1 comprised 14 monochorionic (MC) twin pairs with TTTS treated symptomatically; group 2 comprised 13 MC twin pairs with TTTS treated by laser. The control groups comprised 12 MC twin pairs without TTTS (group 3) and 11 dichorionic twin pairs (group 4). Fetal cardiovascular data, predictive factors for, and duration of TTTS and cord blood were collected prospectively. We measured blood pressure and PWV photoplethysmographically at a median corrected postnatal age of 11 months (range, 1 week to 66 months). Both TTTS groups showed marked intertwin PWV discordance, unlike MCDA control subjects. The PWV discordance seen in laser treated twin pairs resembled that of dichorionic control subjects (heavier individual with higher PWV), whereas group 1 showed the opposite (negative) intertwin discordance (ANOVA F (1,45)ϭ4.5, Pϭ0.04). No significant differences in blood pressure or intrauterine growth were observed between TTTS groups. Conclusions-Vascular programming is evident in monozygotic twins with intertwin transfusion and is altered but not abolished by intrauterine therapy to resemble that seen in dichorionic twins.

Fetal Cardiac Function: Technical Considerations and Potential Research and Clinical Applications

“…Persistent pulmonary hypertension after birth has also been described in some recipient twins [109]. Moreover, recipient twins show increased blood pressure levels already in the neonatal period [110,111], while donors have lowered arterial distensibility [112,113], which might be a response to the chronic activation of the renin-angiotensin system. Therefore, further studies to assess the cardiovascular outcome of twin survivors are warranted.…”

“…However, several studies have also demonstrated that FGR conditions cardiac dysfunction in utero [6,81] that persists postnatally [89], supporting the hypothesis of a primary cardiovascular programming. Apart from FGR, other fetal conditions such as maternal diabetes [69,70], TTTS [113], or in vitro fecundation [138] have also been proposed as prenatal conditionings for fetal cardiovascular programming.…”

Arterial Stiffness in the Young: Assessment, Determinants, and Implications

“…Such vascular programming has been shown to be ameliorated, albeit not completely abolished, by intrauterine endoscopic laser ablation of placental anastomoses 64). Even in monozygotic twins without twin-twin transfusion syndrome, the twin with the lower birthweight has been found to have higher systolic blood pressure and pulse pressure in childhood 65)…”

Survival and neonatal outcome after fetoscopic guided laser occlusion (FLOC) of twin-to-twin transfusion syndrome (TTTS) in Sweden

“…Only a few studies have focused on long term vascular consequences of TTTS. Pulse wave velocity, reflecting vascular stiffness, was found to be increased in the brachial artery of donors compared with recipients, a finding suggested to be an effect of fetal arterial remodeling and a risk factor for later hypertension [55,56]. Furthermore, a meta-analysis of pulse wave velocity studies has confirmed that it is predictive for total cardiovascular events [57].…”