Urine Test
At each pregnancy check-up, the morning urine is routinely checked for albumin and glucose. This test is performed with a urine dipstick that is dipped in the urine and read.
If protein is found in the urine, further differentiation is required:
- Contamination with vaginal discharge.
- Infection of the urinary tract (ask whether there have been micturition problems, examine urine sediment if necessary).
- Gestational hypertension/pre-eclampsia (EPH gestosis/toxaemia).
- Pre-existent or coincidental vascular and/or renal abnormalities.
If glucose is found in the urine, the following should be considered:
- The woman was not fasting. Women regularly forget to save the morning urine on the day of the check up. After breakfast the urine can contain glucose, especially if a lot of sweet food is eaten (e.g. in the case of a low sodium diet); the renal threshold for glucose during pregnancy is lowered.
- Disrupted carbohydrate metabolism. Further tests are necessary if gestational diabetes is suspected.
Blood Tests
As a consequence of the physiological haemodilution (see “Changes in the maternal body”), the haemoglobin concentration in the blood will usually fall to a certain extent. If the haemoglobin level at the start of the pregnancy was normal, it is a single pregnancy and the woman is eating a varied diet, then the haemoglobin level does not need to be checked until about the 32nd week of pregnancy.
An increase in the haemoglobin concentration and the haematocrit can be observed in the case of gestational hypertension/pre-eclampsia. Due to plasma extravasation the blood becomes thicker.