The rule of thumb is most women need about 300 extra calories every day during the last five to six months of pregnancy for good fetal development. This will combine to a healthy weight gain of about one pound each week.
In general, the brain can withstand up to three to six minutes without oxygen before brain damage occurs, but this may vary from person to person.If the brain goes without oxygen longer than this, serious and often irreversible damage is likely to take place.eath is usually declared once the brain has gone more than 15 minutes without oxygen. Although the brain can only go a few minutes without oxygen before some type of brain damage occurs, patients can often regain cognitive function if treated quickly.
The brain cannot go without oxygen for more than ten minutes. If  oxygen is not able to get to the brain before this, then there is a  possibility of irreversible brain dama â¦ ge.