Heteropagus conjoined twins (also known as parasitic twins) are defined as the presence of a nonviable and severely impaired fetus (or fetal parts) attached to a relatively
normal twin (termed the autosite) in one of the same areas in which intact conjoined twins would be united [6].
This is a relatively safe procedure overall but it carries risks such as ruptured membrane and damage to the
normal twin (10%-35% risk).
Twin pregnancy with one
normal twin and one complete hydatidiform mole: the
normal twin usually has its own normal placenta.
The Sahara's engines were the
normal twin cylinder units, each producing 12hp and each with a separate fuel tank.
Results: Out of 875 patients, 75(8.57%) were with no pregnancy, 501(57.25%) with normal single pregnancy, 5(0.57%) with abnormal single pregnancy, 18(2.05%) with
normal twin pregnancy, 2(0.22%) with abnormal twin pregnancy, 4(0.45%) with normal triplets.
The oldest and the most persistent theory of visceral inversion is that twins are often mirror image of each other that a single individual with situs inversus represents a survivor whose
normal twin has died in utero.
Mrs Garret, aged 26, now faces a wait to see if the
normal twin will survive the trauma of surgery.
1: Ultrasound image of Monochorionic (white arrow) Monoamniotic twin gestation Pelvis and lower limbs of
normal twin (*) and subcutaneous soft tissue surrounding the trunk of the pump twin (black arrow).
A reversed arterial flow was noted on Doppler study coming from apparently
normal twin to abnormal twin, fig (2) Diagnosis of TRAP sequence made.
The umbilical cord of the
normal twin was 20 cm with central attachment, while the other umbilical cord was 10 cm long with peripheral attachment.
[5] Blood from the
normal twin reaches the acardia through a large artery-artery anastomosis, flows through the acardia in reverse course and returns to the pump twin via a large vein-vein anastomosis.
Conjoined twins result from incomplete separation of monozygotic, monochorionic twins early in embryonic development, resulting in body parts of the otherwise
normal twins remaining fused throughout development.