210px<unk>  can be attributed to maternal, placental, or fetal conditions. Kingdom and Kaufmann classifies three categories for the origin of fetal<unk> : 1) pre-placental (both mother and fetus are<unk> , 2) utero-placental (mother is normal but placenta and fetus is<unk> , 3) post-placental (only fetus is<unk> . Pre-placental<unk>  is most commonly caused by external<unk>  environments (such as high altitude). It can also be caused by maternal respiratory conditions (such as asthma), cardiovascular conditions (such as heart failure, pulmonary hypertension, and cyanotic heart disease), and hematological conditions (such as anemia). Conditions such as obesity, nutritional deficiencies, infections, chronic inflammations, and stress can also affect the maternal oxygen supply and fetal uptake. The most preventable cause is maternal smoking. Cigarette smoking by expectant mothers has been shown to have a wide variety of deleterious effects on the developing fetus. Among the negative effects are carbon monoxide induced tissue<unk>  and placental insufficiency which causes a reduction in blood flow from the uterus to the placenta thereby reducing the availability of oxygenated blood to the fetus. Placental insufficiency as a result of smoking has been shown to have a causal effect in the development of pre-eclampsia. While some previous studies have suggested that carbon monoxide from cigarette smoke may have a protective effect against preeclampsia, a recent study conducted by the Genetics of Pre-Eclampsia Consortium in the United Kingdom found that smokers were five times more likely to develop pre-eclampsia. Nicotine alone has been shown to be a teratogen which affects the autonomic nervous system, leading to increased susceptibility to<unk> -induced brain damage. Maternal anemia in which smoking has also been implicated is another factor associated with IH/BA. Smoking by expectant mothers causes a decrease in maternal nucleated red blood cells, thereby reducing the amount of red blood cells available for oxygen transport. Utero-placental<unk>  is associated with abnormal placental implantation, impaired vascular remodeling and vascular diseases. It is also associated with pregnancies complicated by gestational hypertension,<unk>  growth restriction, and pre-eclampsia. Post-placental<unk>  is associated with mechanical obstructions of the umbilical cords, reduced uterine artery flow, progressive fetal cardiac failure, and genetic anomalies. The perinatal brain injury occurring as a result of birth asphyxia, manifesting within 48 hours of birth, is a form of<unk>  ischemic encephalopathy.
Intrauterine hypoxia
Neonatal sepsis
Perinatal asphyxia
Positional asphyxia
Neonatal infection
Maternal fetal stress transfer
Traumatic asphyxia
Foetal cerebral redistribution