Amniocentesis for Twin Pregnancies: Is Alpha-Fetoprotein Useful in Confirming that the Two Sacs Were Sampled?

Abstract

Objective: To assess if amniotic fluid alpha-fetoprotein (AFAFP) could be useful to determine if both sacs are sampled during an amniocentesis for twin pregnancies. Method: We reviewed all amniocenteses performed on twin pregnancies over a 5-year period. Inclusion criteria were restricted to pregnancies where both karyotypes and AFAFP were available on each fetus. Pregnancies complicated by fetal anomalies were excluded. The following information was obtained: maternal age, gestational age at the procedure, karyotypes, AFAFP values, pregnancy and neonatal outcome. Placental pathology reports were used to confirm chorionicity. Analysis was performed to evaluate the impact of the fetal gender and chorionicity on the AFAFP values. Results: 260 pregnancies were reviewed. Mean maternal age was 36.9 years (33.6, 40.1). Gestational age at the time of the procedure was 16.2 weeks (14.5, 17.9). Complications included 1.8% of misdiagnosis (discrepancy between karyotype and gender). The difference of AFAFP values between the two fetuses was statistically larger in dichorionic pregnancies than in monochorionic gestations. Fetal gender had no influence on the AFAFP. Conclusion: Amniocentesis in twin pregnancies is associated with a 1.8% risk of misdiagnosis. AFAFP can help to assess the chorionicity of a twin pregnancy. When the difference between the two values is <0.2 MoM and the chorionicity was thought to be dichorionic and the two karyotypes are similar, then failure to sample both sacs should be suspected.

Invasive Diagnostic Procedures in Multiple Pregnancies

“…Recently, the role of amniotic fluid alpha-fetoprotein (AFAFP) values was evaluated in confirmation of both sacs in a DC pregnancy being sampled. 47 Concern regarding potential post-amniocentesis increase in fetal loss rate in multiples has led to a plethora of studies evaluating this parameter. Early reports suggested a higher fetal loss rate in twin pregnancies than in those with singletons.…”

Peri̇natal Sonuçlari Beli̇rlemede Msafp Ve Asafp’ni̇n Yeri̇

“…ASAFP ikiz gebeliğin koryonitesinin değerlendirilmesine de yardımcı olur. İki değer arasındaki farkın <0,2 MoM olması halinde gebeliğin dikoryonik olduğu düşünülmeli ve iki karyotip benzer olduğunda her iki kesenin de örneklenemediğinden şüphelenilmelidir(13).Zekai Tahir Burak Kadın Sağlığı Eğitim ve Araştırma Hastanesine müracaat eden, 16-20. gebelik haftaları arasında yapılan üçlü tarama testinin ardından çeşitli endikasyonlarla amniyosentez yapılmış ve doğumu gerçekleşmiş olan hastalar incelemeye alındı. Gebelik sonucu ile ilgili bilgilere hastalara ait dosya incelemesi ve hastalarla direk görüşme yöntemiyle ulaşıldı.…”