This is an umbrella term that covers three very similar but overlapping conditions namely amniotic band syndrome, amniotic adhesion sequence, and limb-body wall complex. They are probably disruptive sequences secondary to vascular disruption or tissue necrosis and adhesion. The spectrum of pathology includes encephalocele and defects of cranium, cleft palates and other facial abnormalities, autoamputation of digits and limbs, and body wall defects with anomalies of internal organs. The brain is usually normal but cases with developmental abnormalities have also been reported. Karyotypes of affected individuals are normal. In this particular case, it is probably an amniotic adhesion sequence which is characterized by part of the fetus, usually the head, adhering to the placenta.
(Source:University of Oklahoma Health Sciences Center ) http://moon.ouhsc.edu/kfung/jty1/neurotest/Q11-Ans.htm Amniotic adhesion: condition where parts of the fetus and placenta, usually the head and amnion, adhere to each other.