The impact of laser therapy on fetal growth discordance in twin-to-twin transfusion syndrome

Renato A Moreira De Sa,Yves Ville,Yuichiro Takahashi,Masami Yamamoto,Salomon J Laurent

doi:10.1590/s1519-38292005000300007

Abstract

OBJECTIVES: to evaluate the impact of laser therapy on inter-twin discordance in twin-to-twin transfusion syndrome (TTTS). METHODS: biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), femur length (FL) and estimated fetal weight were prospectively collected during a five-year period (1999 to 2004). The inter-twin discordance was expressed as a percentage of the largest twin's measurements. The measurements were made the day before laser, twice following laser and after delivery. The mean values of discordance in measurements and in fetal weight were calculated. ANOVA was used to compare mean values. RESULTS: the mean (SD) discordance for BPD, HC, AC, FL and estimated fetal weight the day before laser were 8.53% (5.28), 8.75% (2.76), 16.19% (4.85), 12.92% (5.13) and 28.50% (6.46) respectively. At the at 2nd ultrasound assessment after surgery were 4.37% (3.55), 3.73% (2.71), 8.90% (4.42), 6.61% (4.99) and 19.11% (8.01) respectively; and at birth the weight discordance was 18.55% (8.74). There was a significant decrease in discordance for HC and AC for each ultrasound assessment. CONCLUSIONS: there was a decrease in fetal growth discordance following laser therapy in TTTS. These changes might be related to re-adaptation of blood flow following laser therapy.

Highlights

Birthweight discordance can affect up to a quarter of twin gestations and is a critical factor in the management of those pregnancies.1,2 The discordance is calculated as the intrapair weight difference, expressed as a percentage of the larger twin's weight.3 The incidence of discordance is directly related to the definition used
Conclusions: there was a decrease in fetal growth discordance following laser therapy in to-Twin Transfusion Syndrome (TTTS)
BPD = biparietal diameter; HC = head circumference; AC = abdominal circumference; FL = femur length. Both the presence of inter-twin anastomoses and unequal placental sharing are likely to be the main causes for fetal growth discordance and amniotic fluid imbalance to develop in TTTS.5

Summary

Introduction

Birthweight discordance can affect up to a quarter of twin gestations and is a critical factor in the management of those pregnancies. The discordance is calculated as the intrapair weight difference, expressed as a percentage of the larger twin's weight. The incidence of discordance is directly related to the definition used. Birthweight discordance can affect up to a quarter of twin gestations and is a critical factor in the management of those pregnancies.. The discordance is calculated as the intrapair weight difference, expressed as a percentage of the larger twin's weight.. The incidence of discordance is directly related to the definition used. Most published studies have used a birth weight difference of 15% to 25 %.3. Twin-to-Twin Transfusion Syndrome (TTTS) is often associated with growth discordance between Donors and Recipients.. Around 20% of monochorionic twins develop TTTS.. The twins are often forced into specific discordant growth patterns, likely to be driven by unequal sharing of nutrients through unequal sharing of the placenta through chorionic plate inter-twin anastomoses.. Laser therapy is the most effective first line treatment of TTTS; its effect on fetal growth has not been evaluated to date Most published studies have used a birth weight difference of 15% to 25 %.3 Twin-to-Twin Transfusion Syndrome (TTTS) is often associated with growth discordance between Donors and Recipients. Around 20% of monochorionic twins develop TTTS. The twins are often forced into specific discordant growth patterns, likely to be driven by unequal sharing of nutrients through unequal sharing of the placenta through chorionic plate inter-twin anastomoses. Laser therapy is the most effective first line treatment of TTTS; its effect on fetal growth has not been evaluated to date

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