So once again, normally what happens is as soon as the oxygen rushes into the lungs of that fetus, the lungs begin to produce the protein known as brady kinan. And bradykinan only functions in the presence of plentiful oxygen. So what brady kinan does is it moves into the ductus arteriosis that now contains a bunch of oxygen molecules and it uses that to close off and see loft the ductus arteriosis. Now, suppose that individual of that fetus is born under hypoxic conditions and that means they do not have enough oxygen circulating inside their blood. In such a case, the bradyclinan cannot actually act effectively and efficiently because there is not enough oxygen. So it will not be able to seal off that ductus arteriosis.