Weight Gain in Pregnancy

Weight Gain in Pregnancy

The importance of the amount of weight gained during pregnancy cannot be over-emphasized as the welfare of both the mother and her child can be directly related to it.

Most women gain weight during pregnancy but the amount varies not only from woman to woman but also from pregnancy to pregnancy. It is impossible to set down a rigid rule which states exactly how much weight a given person should or should not gain during pregnancy especially since the weight at the onset of pregnancy exerts a big influence on this. A woman of average build and height on unrestricted diet will gain in the region of 12.6 kg. throughout pregnancy.

Weight Gain in PregnancyThe weight will usually fall in the first three months due to nausea, vomiting and loss of appetite. This actual weight loss may vary from just .5 or 1 kg. to as much as 9 or even 14 kg. especially if there is severe vomiting. The gain in weight usually starts about the 12th to the 14th week of pregnancy when the nausea and sickness is naturally relieved and a sense of well-being encourages the woman to eat and drink more than she might do otherwise. Weight gain up to the 20th week, however, is not usually very great. The greatest increase occurs between the 20th and 30th week of pregnancy, and many obstetricians take exception to excessive weight gain in this particular phase because weight gain during this time is associated with a much higher incidence of pre-eclampsia. The speed of weight gain slows after the 30th week and gradually diminishes until about the 38th or the 39th week of pregnancy after which there is very often a fall in weight.

Ideal Weight Gain

The gain in weight during pregnancy is the result of many factors. There is an increase in the size of the various organs, notably the breasts and the uterus; there is the weight of the foetus itself together with the placenta and the amniotic fluid; there is a natural increase in the mother’s circulating blood volume by as much as 30 per cent to supply the demands of the uterus and the breasts as well as the rest of the body. These factors together account for approximately 8 kg. and a total gain of 8 to 9 kg. is all that should be allowed throughout pregnancy.

The final weight gain associated purely with the pregnancy itself is:

The weight of the baby   3-2 kg.
The weight of the placenta  .67
The weight of the amniotic fluid  .91
The weight of the uterus (normally 85 gm.)  .91
Increase in weight of the breasts  .67
Increase in circulating volume of blood  1.81
     Total:  8.2 kg.

Any extra weight is due either to fat or to fluid retention.

The scheme to be aimed at is:

0-14 weeks:    No weight gain.
14-20 weeks:  Total of 2-3 kg.
20-30 weeks: Total of 4-5 kg. This is the most difficult period of pregnancy with regard to restricting weight gain but it is also the most important.
30-36 weeks: Total of 2-3 kg.
36-40 weeks: No weight should be gained, and indeed from the 38th week onwards a pregnant woman will very frequently lose weight.

Excessive fluid retention, and consequent increase in weight, may occur at any stage during pregnancy and results from the presence of a high level of hormones (which may play a part in the cause of pre-eclampsia) or an excessive intake of salt or spicy food, or both factors together.

Early in pregnancy none of these factors are operative and weight remains constant or actually falls. At about the 10 th week when the circulating blood volume starts to increase there may be some weight gain. At this stage or shortly afterwards food intake may be increased when nausea and vomiting cease. Towards the 14th week the appetite returns, and women may eat too much of the wrong type of food. There is no truth in the saying that a pregnant woman should ‘eat enough for two’. She should, however, have a good adequate diet and supplements such as vitamins, iron and calcium are essential. A weight gain between the 20th and 30th week of more than 4.5 kg. predisposes to pre-eclampsia with the resulting harm to both the mother and to her baby. The pattern of weight gain changes once more after the 30th week of pregnancy. Sudden and dramatic increases may occur, usually as a result of fluid retention which may be a sign of the onset of pre-eclampsia. The amount of weight gained usually diminishes from about the 35th week of pregnancy and may cease altogether at about the 38th week of pregnancy or as the expected date of delivery is approached. One of the most reliable signs of full maturity is actual loss in weight even though this may amount to only  .5 or 1 kg.; it may occur at any time after the 38th week and labour usually follows within 7 to 10 days of such a fall. However, if it does not begin there is no need for concern. Weight loss towards the end of pregnancy is due to a reduction of hormones which is considered, by many people, to be one of the causes of the onset of labour.

Fierce arguments rage upon the amount of weight which a person may be permitted to gain in a normal pregnancy. Many consider that it should be between 9 and 13 kg. for the average woman of average build. Some women, however, who diet to reduce their Weight artificially prior to the onset of pregnancy often discover that the weight previously lost is replaced with alarming ease at the beginning of their pregnancy. Such women may find it very difficult not to gain more than 13 kg. Conversely, some women whose pregnancy commences when they are grossly overweight need gain no weight at all throughout their pregnancy providing they diet carefully for the whole duration. This was well illustrated by a woman who weighed 150 kg. before the onset of pregnancy and, suffering from severe nausea and vomiting throughout most of it, weighed 115 kg. at delivery. Her baby was absolutely normal and four weeks after delivery she weighed 108 kg. Still perhaps a little overweight !

All weight gained in excess of 8 or 9 kg. will remain after delivery and will be distributed over the shoulders, upper arms, chest, abdominal wall and thighs.

Excess Weight Gain

Every pregnant woman ought to have access to a weighing machine, either at home or in the clinic, where she can check her weight. If she is gaining too much weight it means that she is not adhering to the diet prescribed below. The first thing for her to do is to read through her diet and see what she is eating incorrectly. This is nearly always found to be carbohydrate, in the form of sugar or flour, and their intake must be very carefully checked and reduced accordingly. Most people on a diet tend to nibble between meals, especially cheese, and this is to be discouraged unless such nibblings consist of fruit alone. It is not generally realized that cheese has an extremely high calorie content and will cause an increase in weight more rapidly than most other foods. Its intake should be strictly limited.

Milk is invariably prescribed for most pregnant women and is of inestimable value for those people who are under-nourished or whose diet is inadequate. It is true that milk contains a certain amount of vitamins and also calcium, but it also has a fairly high calorie content. A person who is eating a well balanced and normal diet does not require to drink half a litre a day. Many women adhere rigidly to a basic diet but by eating large amounts of cheese and drinking half a litre or more of milk a day proceed to put on an undue amount of weight.

An unlimited amount of fluid may be drunk throughout the whole of pregnancy, but the calories in the drink must be carefully estimated —always remembering that milky drinks and processed fruit juices have a relatively high calorie content. Tea and coffee may be drunk freely, providing only a small quantity of sugar is added. Alcohol also has a high calorie value and pregnant women should be reasonable in their alcohol intake anyway.

Remember, 9 kg. is the limit.

Rich and indigestible foods should be avoided, for example curry, cream, fried food and strong tea, especially as some women are more prone to indigestion during pregnancy.

During pregnancy a woman needs to ensure that she is taking a well balanced and adequate diet. The list given below shows the foods which are richest in the various nutrients essential during pregnancy, but any normal well balanced diet contains an ample and sufficient amount of almost all these items.

Diet during Pregnancy

Eating the right foods during pregnancy helps to ensure a healthy baby. Don’t eat more than usual—the old idea of ‘eating for two’ is mistaken and pregnancy is far more enjoyable if you avoid putting on too much weight; the aim should be to put on no more than 9 kg. during the whole pregnancy.

The baby is a parasite. He will take what he requires from his mother even to the detriment of her general health. For ease of growth and development it is necessary to provide the growing baby with an ample amount of those foods that he requires, and it is essential to supply the mother with sufficient to meet the demands of her baby. A pregnant woman can remain perfectly fit and healthy without gaining an excessive amount of weight.

The human body, and especially the baby, requires a great variety of foods, including minerals, for growth and development, the vast majority of which can be found in a normal balanced diet. The diet should contain (i) an adequate quantity of protein, (2) a reasonable amount of fresh fruit and vegetables, (3) a moderate amount of carbohydrate, (4) a moderate amount of fat and (5) adequate fluid. Under normal circumstances the average person eats a reasonably well balanced diet.

Protein. The foods which contain protein are all types of meat such as beef, pork, poultry, lamb, veal, kidneys, liver, tripe, heart, sweetbreads. All kinds of fish such as sardines, haddock, kippers, herrings, sole, salmon, shrimps, lobsters, pilchards, oysters, prawns; also eggs, cheese and milk. Some vegetables such as peas, beans, nuts and lentils contain protein.

Carbohydrate is found in large amounts in anything which contains flour or sugar. The main carbohydrate foods are sugar, all bread, cereals, rice, potatoes, spaghetti, macaroni, cakes, pastries, sweets, jams, honey, chocolates, syrup.

Fats. Most of the foods which contain fat are obvious. They include fatty meat, especially bacon, margarine, butter, milk, cream, cheese, mayonnaise, lard, salad dressing, cooking oil, cooking fat, nut and fish oils.

Vitamins. A plentiful supply of vitamins is essential for the baby’s growth as well as for the mother’s health.

Vitamin A is present in all fish oils, especially cod liver oil, also in egg yolk, offal (such as liver, heart, kidneys), milk, cheese, butter, margarine, most fruits such as bananas, peaches, apricots— especially when fresh (there is not much vitamin A in these fruits when they have been dried or cooked)—vegetables, especially spinach and tomatoes, also turnips, beetroot, carrots, brussels sprouts.

Vitamin B1 is found mostly in the seeds of plants like beans, peas, nuts and wheat (from which wheat germ oil is made) as well as crude rice and soya bean. It is also found in yeast and uncooked yeast, in eggs, liver, brain, heart, seafoods (especially fish oils) and in proprietary preparations such as Bemax and Marmite.

Vitamin B2 is present in meat, liver, kidneys, heart and brains and all fish and shell fish and also in nuts, milk, cheese, cream, yeast, whole wheat, peas and beans.

Vitamin C is present in most fresh fruits, especially oranges, lemons, tangerines, grapefruit, tomatoes, blackcurrants, melons, strawberries and also in vegetables such as cabbage, lettuce, carrots, radishes, brussels sprouts, watercress and broccoli, and in milk. Vitamin C is destroyed by cooking or heating.

Vitamin D is present in nearly all fish oils and fish extracts, as well as in most animal fats, eggs, cheese, butter and milk. Vitamin D is essential for the satisfactory metabolism and absorption of both-calcium and phosphorus used in bone building. So that the foetus has an adequate calcium supply the pregnant woman must have an adequate level of vitamin D. It should be noted, however, that the amount of vitamin D given to the pregnant woman must be carefully controlled since it is possible to take too much of this particular vitamin. One of the advantages of sunbathing is that vitamin D is formed in the skin by the action of ultra-violet light on it. This does not, however, mean that sunbathing is essential or even a good thing during pregnancy, but there is certainly no harm in it. You should not use an ultra-violet sun-ray lamp during pregnancy.

Vitamin E is thought to be necessary to establish pregnancy, but its value during pregnancy is doubtful. It is found in most germinating seeds and eaten in the form of wheat germ oil and cotton seed oil. Small quantities are also present in eggs, milk, butter, cheese, unpolished rice, wholemeal bread and wheat.


Contrary to popular belief, milk is not essential for the pregnant woman. It is a very good, and indeed a perfect, food rich in calcium and vitamin C, but if you are taking an adequate well balanced diet you need not drink it as it only increases calorie intake and, therefore, weight gain. You can get the calcium requirement from other foods or even from tablets. However, for the really under-nourished or under-privileged, and those who cannot obtain an adequate diet, milk forms an ideal food.

Sugar and Sugar Substitutes

An increase of sugar intake during pregnancy is unnecessary. It is a general principle that an excessive amount of sugar should be avoided in the diet. Some sugar substitutes, especially cyclamate, are known to cause congenital abnormalities in animals when administered in high dosage, and although there is no definite evidence of this in the human they should be avoided. Recent legislation has been helpful in removing the cyclamates from the market so that sugar substitutes now available are quite safe.

Iron and Supplementary Elements

Iron is essential for the formation of haemoglobin, which is one of the main constituents of the red blood cell and carries oxygen around the body. A deficiency of iron causes anaemia and one of the most important aspects of antenatal care is the prevention of anaemia in the mother. Iron is to be found in nearly all meat, especially liver and kidneys, as well as in eggs, green vegetables such as spinach, cabbage, brussels sprouts and broccoli. Small quantities are present in root vegetables as well as in fish.

Calcium is one of the most important elements for the growth of the foetus and if the mother has insufficient calcium she may suffer from osteomalada where the foetus takes calcium from her bones and they become softened and bent. This is occasionally seen in some developing countries where a woman has had many children. The loss of calcium from the mother during pregnancy has nothing to do with dental caries or bad teeth. Calcium is found in cheese, milk and cream. It is also present in fish, nuts, eggs and green vegetables such as broccoli and spinach.

The trace elements—phosphorus, copper, iodine, manganese, magnesium and cobalt—are essential for the formation of blood cells and many other tissues in the body. Only minute quantities are required by the body for its satisfactory function. A complete absence of them, however, will lead to gross deficiencies. The majority of these elements are found in small amounts in most of the proprietary iron preparations that are available.

Phosphorus is present in seafoods, cheese, eggs, milk, meat, onions and wholemeal bread.

Copper is present in most meat, liver, cheese and beans.

Iodine is present in nearly all fish foods and fish extracts. It is also possible to buy iodized salt which is sold in those areas where there is a natural shortage of iodine which can lead to the formation of goitre.

Manganese is found in most vegetables, especially peas, beans, wheat products, green vegetables and also in animal liver.

Magnesium is present in peas, beans, nuts and grain foods.

Folic acid is now accepted as a routine supplement during pregnancy although it is found in green leaf vegetables, yeast, liver and kidneys. A deficiency of folic acid causes megaloblastic anaemia, a particular type of anaemia which only affects pregnant women. Between 5 and 10 per cent of all pregnant women suffer from it, especially those who have repeated pregnancies at very short intervals and those who are expecting twins or triplets.

Folic acid may be administered as a separate tablet but is usually combined with the ordinary iron in one tablet. You will be told how many tablets you should take each day and these will provide you with all the iron and folic acid you require.

Pica (Abnormal Food Desires)

Some women develop abnormal and very peculiar likings for strange food during pregnancy. These are slightly different from the sort of food craze that affects everyone at times and to which most women are subject intermittently throughout their pregnancy. The result is a real craving for a particular type of food which they would not normally eat. These cravings are usually associated with materials that contain iron. Such food cravings are very uncommon today, but used to be very frequent in the past. There are many documented instances of women eating soil and coal, which in retrospect are interpreted as a subconscious desire to obtain iron.

Pica today is a rare phenomenon and is not to be confused with a particular liking for certain foods which women develop during pregnancy. Unfortunately, the likings are usually for carbohydrate foods and are therefore followed by undue weight gain. They can be controlled. On the other hand pica is almost completely uncontrollable and it is only with extreme difficulty that the women can be weaned away from her abnormal desire. The primary treatment for such conditions is, of course, to correct any anaemia or vitamin deficiency.