Laser Surgery Reduces Serious Complication of Identical Twin Pregnancy

Researchers at the Fetal Care Center of Cincinnati (OH, USA) evaluated the incidence of complications in 152 cases of TTTS that were treated with selective fetoscopic laser photocoagulation between 2005-2008. The complications measured were TTTS recurrence, amniotic band syndrome, iatrogenic monoamnionicity, and twin anemia-polycythemia sequence. The data were categorized as no complications; early complications (equal or less than seven days); late complications (appearing later than seven days); and both early and late complications.

The researchers found that the incidence of early, late, and both early and late complications was 31%, 39%, and 10%, respectively. Complications included two cases of monoamnionicity, three cases of recurrent TTTS, three cases of twin anemia-polycythemia sequence, and five cases of amniotic band syndrome. Cases with TTTS with early complications had a lower number of superficial arteriovenous vascular anastomoses and one or both fetus survival, compared with no complications. In all, fetal survival was 238 of 307 cases (77.5%), with one or both twins surviving in 134 of 152 (88%) of pregnancies. The study was published in the October 2009 issue of the American Journal of Obstetrics & Gynecology.

In identical twin pregnancies with TTTS, the fetal blood supply is abnormally connected within a shared placenta. Although each fetus uses its own portion of the placenta, the connecting vessels allow blood to pass from one twin to the other. Depending on the number, type, and direction of the interconnecting blood vessels, blood can be transferred disproportionately from one twin to the other. This causes the donor twin to have decreased blood volume, retarding its development and growth, while the larger recipient is at risk of heart failure due to an overworked heart. If untreated early in pregnancy, in 80-90% of cases, both twins will die. In rare cases, the condition can happen with triplets or higher multiples, when a pair of fetuses shares one placenta. The condition is usually diagnosed during the second trimester with a routine ultrasound.

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Fetal Care Center of Cincinnati