Pregnant Mothers | Back to Vulnerable Groups List
During pregnancy a woman's hormone levels alter. The hormone most relevant to undesirable weight gain is oestrogen. As the pregnancy progresses, oestrogen levels rise, particularly in the last six months of pregnancy. The amount the oestrogen rises varies with the individual, but the more it rises, the more the woman is vulnerable to salt. If during this vulnerable time she eats salty food, her blood volume will rise more than it would if she were not eating salty food. This is because high oestrogen in the blood stream causes the muscles in the walls of the blood vessels to relax and so the blood vessels allow in more sodium and the water it attracts to itself. The veins become swollen.
When the baby is born the hormone levels change again and the oestrogen level goes down. The muscles in the walls of the blood vessels tighten up again and some of the excess salt and water in the blood is excreted. But if the veins were badly overstretched and weakened during the pregnancy, the woman will not return to her former weight. With each succeeding pregnancy, the problem will worsen; the veins will become weaker and more swollen; the blood volume will rise; she will become more overweight.
Essentially, to avoid gaining undue weight during pregnancy you need to reduce the amount of salt you eat and eat plenty of fresh fruit and unsalted vegetables. If you eat as little added salt/sodium as possible you will avoid unhealthy weight gain from fluid retention and lower your risk of high blood pressure and of pre-eclampsia, and also lower your risk of developing gestational diabetes. You will suffer less tiredness during the pregnancy. And you will be doing the best for your baby.
Breastfeeding, if you can manage it, will also give your baby a healthy start, for many reasons. - One of those reasons is that breast milk tends to be low in sodium and this can protect your baby from becoming unhealthily overweight.
See also my Fat Retention page.
And please read my Disclaimer.
I have modified my original belief that the excess fluid is all in the blood vessels. I now believe that most is in the blood vessels, while some may be in the abdominal cavity (ascites), and some in the body tissues.
Pregnant women should be strongly advised to avoid eating salty food during pregnancy. Foods high in potassium, such as fresh fruit and vegetables, can displace sodium in the body, so they are particularly good for pregnant women.
If childbirth has caused you to become overweight you can easily lose a lot of the excess weight by reducing your salt intake. You need to make plenty of fruit and vegetables and a low salt intake permanent features of your eating.