Prenatal ultrasonographic diagnosis of thoracopagus conjoined twins

Vaginal Delivery of Dicephalic Parapagus Conjoined Twins: Case Report and Literature Review

“…Conjoined twins (CTs) are always derived from one fertilized ovum, and are monochorionic (shared placenta) and monoamniotic (shared amniotic sac) (Quiroz et al 1989;Hammond et al 1991). They occur once in every 2,800 to 250,000 births, with incidence usually cited as 1 per 50,000 to 100,000 deliveries (Fitzgerald et al 1985;Quiroz et al 1989;Barth et al 1990;Hammond et al 1991;Itoh et al 1993;Shija et al 1994;Creinin 1995;Bianchi et al 2000;Bondeson 2001;Daskalakis et al 2004;Tansel and Yazicioglu 2004).…”

“…They occur once in every 2,800 to 250,000 births, with incidence usually cited as 1 per 50,000 to 100,000 deliveries (Fitzgerald et al 1985;Quiroz et al 1989;Barth et al 1990;Hammond et al 1991;Itoh et al 1993;Shija et al 1994;Creinin 1995;Bianchi et al 2000;Bondeson 2001;Daskalakis et al 2004;Tansel and Yazicioglu 2004). They may be more common in parts of Asia and Africa (Shija et al 1994).…”

“…(Spencer 1992;Itoh et al 1993;Machin 1993). The first asserts that incomplete fission of a single embryonic disc occurs 13 to 15 days after the ovum is fertilized (Quiroz et al 1989;Barth et al 1990;Hammond et al 1991;Machin 1993;Creinin 1995;Sen et al 2003;Tansel and Yazicioglu 2004). Spencer (1992) proposed a second theory: that a fertilized ovum divides completely into two embryonic discs whose unusual proximity results in secondary fusion into CTs as the embryos enlarge.…”

“…Diagnosis of CTs before birth allows practitioners to minimize injury by planning a suitable delivery (Fitzgerald et al 1985;Sakala 1986;Quiroz et al 1989;Barth et al 1990;Hammond et al 1991). Therefore, careful ultrasound examination is recommended for all suspected twins (Fitzgerald et al 1985;Quiroz et al 1989;Barth et al 1990;Hammond et al 1991).…”

“…Therefore, careful ultrasound examination is recommended for all suspected twins (Fitzgerald et al 1985;Quiroz et al 1989;Barth et al 1990;Hammond et al 1991). First or second trimester detection of CTs enables obstetricians to counsel parents about potential termination, or about delivery and treatment options if pregnancy is continued (Apuzzio et al 1984;Fitzgerald et al 1985;Quiroz et al 1989;Barth et al 1990;Yang et al 1994;Mackenzie et al 2002;Sen et al 2003;Daskalakis et al 2004).…”