See also
Craniopagus parasiticus is another form of partial twinning which results in two heads kept alive by a single torso. In these cases a second, vestigial torso is present, and the heads are joined directly to one another. Diprosopus is a condition in which there are duplicated facial features on one head. Polycephaly is a general term about organisms with more than one head. == References ==
After a grade III or IV IVH, blood clots may form which can block the flow of cerebrospinal fluid, leading to increased fluid in the brain (hydrocephalus). Prevention
Head positioning in very preterm infants has been suggested as an approach to prevent germinal matrix haemorrhage; however, further research is required to determine the effectiveness at reducing mortality and the most appropriate positioning technique. Approaches include bed tilting, supine mid-line head positioning, supine head rotation 90 degrees, prone mid-line head positioning, head tiling. Treatment
Treatment focuses on monitoring and should be accomplished with inpatient floor service for individuals responsive to commands or neurological ICU observation for those with impaired levels of consciousness. Extra attention should be placed on intracranial pressure (ICP) monitoring via an intraventricular catheter and medications to maintain ICP, blood pressure, and coagulation. In more severe cases an external ventricular drain may be required to maintain ICP and evacuate the hemorrhage, and in extreme cases an open craniotomy may be required. In cases of unilateral IVH with small intraparenchymal hemorrhage the combined method of stereotaxy and open craniotomy has produced promising results. Infants
There have been various therapies employed into preventing the high rates of morbidity and mortality, including diuretic therapy, repeated lumbar puncture, streptokinase therapy  and a combination novel intervention called DRIFT (drainage, irrigation and fibrinolytic therapy). More research is required, in the form of high quality randomized controlled trials, to determine the safety, dosing, and effectiveness of prophylactic heparin and antithrombin treatment for preterm neonates.