The average person uses about four bushels of air a minute. Consequently, rooms that are occupied must be constantly replenished with fresh air; otherwise the point is quickly reached where the occupants are breathing an atmosphere that is not only poor in oxygen but saturated with carbonic acid gas and other impurities conveyed by the breath. Foul air such as this causes headache, dizziness, faintness, nausea, and occasionally even more serious disturbances. Those who live in "close" rooms day after day grow pale and languid; their appetite fails and some of their natural power of resistance against illness is lost. Many people are unhealthy simply because they neglect to supply their living quarters with a steady stream of air from the outside.
While it is impossible to keep the air in any room as pure as the outside atmosphere, perfectly satisfactory ventilation can be easily arranged. Some of the impure air in a house is always escaping of its own accord and its place is taken by air from the outside. Thus, the cracks around the windows and doors let bad air out and good air in; and, besides, most building materials are porous. These natural paths, however, must be supplemented. The simplest device for ventilation, which is also the best, consists in opening a window at the top and bottom. The width of the opening may be regulated so as to permit the air in the room to change without occasioning disagreeable drafts; if necessary the current may be broken by a screen of some pervious material placed in the opening.
The bed-room should always be supplied with plenty, of fresh air, which "quiets the nerves" and helps one to sleep soundly. Furthermore, the temperature of the bed-room should be lower than the temperature of rooms occupied during the day. Both these requisites will be properly met by leaving a window open at night, which may be done throughout the year in most climates, if one puts on enough covering. There is no danger of catching cold from sleeping with the window open; on the contrary, breathing fresh air day and night is one of the best ways to prevent colds.
OUTDOOR EXERCISE.—Outdoor exercise is indispensable to good health. It benefits not only the muscles, but the whole body. By this means the action of the heart is strengthened, and consequently all the tissues receive a rich supply of oxygen. Exercise also promotes the digestion and the assimilation of the food. It stimulates the sweat glands to become more active; and, for that matter, the other excretory organs as well. It invigorates the muscles, strengthens the nerves, and clears the brain. There is, indeed, no part of the human machine that does not run more smoothly if its owner exercises systematically in the open air; and during normal pregnancy there is no exception to this rule. Only in extremely rare cases—those, namely, in which extraordinary precautions must be taken to prevent miscarriage—will physicians prohibit outdoor recreation and, perhaps, every other kind of exertion. Under such circumstances the good effects that most persons secure from exercise should be sought from the use of massage.
The amount of exercise which the prospective mother should take cannot be stated precisely, but what can be definitely said is this— she should stop the moment she begins to feel tired. Fatigue is only one step short of exhaustion—and, since exhaustion must always be carefully guarded against, the safest rule will be to leave off exercising at a point where one still feels capable of doing more without becoming tired. Women who have laborious household duties to perform do not require as much exercise as those who lead sedentary lives; but they do require just as much fresh air, and should make it a rule to sit quietly out of doors two or three hours every day. It will be found, furthermore, that the limit of endurance is reached more quickly toward the end of pregnancy than at the beginning; a few patients will find it necessary to stop exercise altogether for a week or two before they are delivered.
Walking is the best kind of exercise, but long tramps are inadvisable during pregnancy, except for those who have previously been accustomed to them. Most women who are pregnant find that a two or three-mile walk daily is all they enjoy, and very few are inclined to indulge in six miles, which is generally accepted as the upper limit. Perhaps the best way to measure a walk is by the length of time it consumes. Accordingly, a very sensible plan is to begin with a walk just long enough not to be fatiguing and to increase it by five minutes each day until able to walk an hour without becoming overtired. It is always advisable not to crowd the exercise of a day into a single period but rather to take it in several installments, for example, an hour in the morning, and another in the afternoon. Under all circumstances, it must never be forgotten that the feeling of fatigue is a peremptory signal to stop, no matter how short the walk has been.
Very few outdoor sports can be unconditionally recommended to a prospective mother. Because athletic exercise is either too violent or else jolts or jars the body a great deal, it is especially dangerous in the early months of pregnancy—the only time when it is likely to be at all attractive. Croquet, alone, perhaps, is free from these objections. Although golf and tennis are by no means certain to bring on miscarriage, they involve a risk which, slight though it may perhaps be, will not be assumed by cautious women.
Horseback riding during pregnancy is injurious. We occasionally hear of women who have ridden horseback without immediate harmful consequences, but they have nevertheless exposed themselves to danger unnecessarily. It is better to give up skating and dancing also than to run the risk of accident, especially since these diversions are attended with some danger of falling. In a general way, whenever the question of entering into any kind of recreation must be decided, it is wise to err on the conservative side rather than risk overstepping the limit of endurance and having to pay a penalty more or less severe.
Carriage riding cannot take the place of walking and can scarcely be classed as exercise; it is wholesome, nevertheless, because it takes the participant out of doors and provides a change of scene. Certain details, however, should be carefully observed; thus, a safe horse, a carriage that rides easily, and smooth roads should be selected. Similar advice pertains to motoring; with smooth roads, a cautious driver, and a comfortable machine, short rides in an automobile are not harmful. Carriage riding and motoring are particularly serviceable as a means of getting outdoor diversion during the last few weeks of pregnancy.
MASSAGE AND GYMNASTICS.—If a prospective mother is obliged to stay in bed several weeks, massage may be useful; otherwise there is no necessity for this treatment. Whenever required, massage should if possible be given by an experienced masseuse. If this is out of the question and the patient must rely upon one of her friends, it should be understood that "general massage" is needed; in other words, one part of the body after another should be gone over systematically. With an inexperienced masseuse, however, it will be safer not to massage the abdomen, since awkward, vigorous, or prolonged manipulations in that locality may provoke painful uterine contractions. Rubbing the breasts also can do no good; on the contrary, it may do harm by bruising them.