Certain of these fibers encircle the mouths of the blood- vessels which have been left open through the detachment of the placenta.

Cocaine use during pregnancy can cut off oxygen to the fetus, killing it, or causing such complications as premature delivery or the detachment of the placenta from the womb.

On average, smokers have more complications of pregnancy and labour which can include bleeding during pregnancy, premature detachment of the placenta and premature rupture of the membranes.

Complications of pregnancy caused by maternal smoking include premature detachment of the placenta and premature or prolonged rupture of the membranes, which carry high risks of perinatal death.