Introduction
Monochorionic(MC) multiple pregnancies especially twin pregnancies, may
be complicated by specific and serious complications, such as selective
intrauterine growth restriction(sIUGR), twin-twin transfusion
syndrome(TTTS), twin reversed arterial perfusion(TRAP), discordance for
structural anomalies and twin anemia polycythemia sequence(TAPS).
Untreated complicated MC multiple pregnancies disease may result in
higher perinatal morbidity and mortality1.It is still
controversial about whether selective reduction or laser ablation of
placental anastomoses is preferred for MC twins complicated with sIUGR
or TAPS, while fetoscopic laser ablation was recognized as first-line
treatment for stage Ⅱ to Ⅳ TTTs diagnosed before 26 weeks gestational
age1. However ,in some situation, selective reduction
is not a bad option due to few hospitals can perform laser ablation but
fetal intrauterine condition are critical, especially in our country.
Moreover, it can save one of the twin with a low risk of
neurodevelopment impairment2.
During the recent years, radio frequency ablation has been widely used
in many clinical therapies, such as neoplasm ,some heart
disease3, human liver lesion, fetal congenital cystic
adenomatoid (CCAM) 4, human fetal sacrococcygeal
teratoma 5, and complicated monochorionic twin
pregnancies 6, 7.While, it seemed that RFA is more
minimal invasive to fetus and pregnant women than other methods for
selective reduction used in multiple pregnancies. RFA was the most
common technique for monochorionic multiple pregnancies selective
reduction8.
The inserted angle is one of key points in the procedure of RFA.
Usually, the procedure was conducted under direct real-time sonographic
guidance, RFA needle was percutaneously inserted through the maternal
abdomen wall into the intrauterine fetal abdomen at the level of the
cord insertion site of the complicated twin7. However,
fetus were positioned prone and remained throughout the whole procedure.
Fetal back may can be alternative needle insert angle. However, the
needle needs to pass through fetal spine which may obviously increases
the difficulty and extended the procedure time of RFA. We hypothesis
that the prenatal and postpartum outcome were worse in the cases through
fetal dorsal insert angle.
In our study, the aim was to assess the risk factors for adverse
pregnancy outcome in the RFA selective reduction procedure due to the
complicated MC twin pregnancies and to compare the pregnancy outcome of
two different needle insert angles in the RFA procedure.