When one is pregnant, the fetus becomes very sensitive if there is a certain change of PH level in the body. This is because; when one is pregnant the P level keeps changing throughout the tenure.
PH in pregnancy causes all the pregnancy related complications if it is not balanced. This can lead to vomiting, swelling, nausea and heart burn. And when this happens one needs to control it by reducing the intake of foods which are acid forming in nature. One needs to replace them with more alkaline forming foods. So as a solution one can eat food items that is solid in nature.
The body never changes their PH level much when one drinks something which has alkaline or high in PH and if there is any change then it is very quickly reversed. But when one consumes some antacid solution like bicarbonate then it can neutralize the acidity present in the stomach. This in turn will increase the PH level in stomach and eases the situation. It also gives relief to heartburn which happens due to the stomach acid leaking and going up to the oesophagus.
In general the human body and metabolism is very much tuned with the PH level and in the body system there are multiple things that keep the PH level in a very tight range. This also happens with other things like blood pressure, body temperature and the balance between water and different electrolytes present in the cell and in the body fluids. This is also known as homeostasis. This mechanism mostly maintains the PH of the blood in a human body at 7.4. When the PH drifts upwards or downwards then the body starts reacting. When the PH level drops below 7.35 then it is called acidosis and when it goes more than 7.45 it is known as alkalosis.
It is also very normal to become mildly acidic and mildly alkali at some point of times but in most cases PH level goes wrong when there are problems with lungs or kidney because they play very major roles in PH balance. The digestive system can produce changes in body pH as well, through vomiting and diarrhoea, but not on the basis of the PH of food that you consume.
Primarily blood itself tries to resist the change in PH because there are chemical buffers and some phosphate ion buffers too. When the PH level drops the breathing rate increases and in this process one exhales carbon dioxide much faster than normal. Now as a result of this there is a decrease in CO2 concentration. So if one exercises vigorously they produce lactic acid and it begins to acidify the blood but the lungs keep the PH level in check.
As for the kidneys, they control the concentration of bicarbonate and other ions in the blood. Temporary changes in blood PH can result from power events, like changes in your breathing rate, vomiting out your stomach acid.
To check PH levels in pregnancy one needs to concentrate on their diet.