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.
Studies show that if you meet the criteria for continuous oxygen use, using it less than 18 hours a day is probably equivalent to using none at all. If your doctor prescribes 24-hour daily oxygen therapy you should try to use it as close to 24 hours a day as practical. Of course there are times you may need to take it off, when you shave or put on make-up or do other daily hygiene. This is not harmful for short periods of time.