A number of things:
Drugs
smoking
or the umbilical cord around the neck
Low energy intake causes the brain to work at a slower speed.
The mother is the "host" for the fetus until birth. All nutrition and growth support is done by virtue of the mother's umbilical cord. IT provides all oxygen and nutrition while connected.
Hypoxemia (low oxygen levels in the blood) will affect the entire brain.
it can cause brain damage
There are many causes to low heart rate in unborn babies. One of the causes could be not enough oxygen to the baby.
Brain damage can occur if an infant's oxygen level drops below 85-90%. Prolonged periods of low oxygen levels can lead to hypoxia, causing damage to the brain and other vital organs. It is important to monitor infants closely and seek immediate medical attention if there are any concerns about oxygen levels.
Smoking tobacco causes highers chance of miscarriage up to 3 months and also low birth weight.
Humans lose consciousness when the oxygen supply to the brain gets low.
Yes males are born with a low level of testosterone. It starts in the womb, Estrogen causes a fetus to become a girl & elevated Testosterone causes a fetus to become a boy. Males have a higher level of Testosterone throughout their lives & females have a higher level of Estrogen.
Unconsciousness can result from various causes, including head trauma, which may lead to concussion or brain injury; medical conditions such as stroke or seizure; intoxication from drugs or alcohol; severe hypoglycemia due to low blood sugar; and lack of oxygen from respiratory failure or drowning. Each of these causes affects the brain's ability to maintain consciousness, often requiring immediate medical attention.
I'm not quite sure how it would ENHANCE oxygen transfer, but hemoglobin itself is what is in blood and is responsible for the carrying of oxygen to different parts of the body. So the hemoglobin in a fetus would just be what is used to get the oxygen from the mothers blood into its blood.
Oxygen deprivation in fetuses can be determined by monitoring the fetal heart rate patterns using electronic fetal monitoring. This can be done during labor and delivery to assess the oxygen supply to the fetus. Other signs such as decreased fetal activity or low oxygen levels in the mother's blood may also indicate oxygen deprivation in the fetus.