Pregnancy is an exciting time, but it can also be filled with many questions and uncertainties, especially for first-time mothers. One of the ways a woman can get insight into her health and the health of her growing baby during pregnancy is through urine tests. Urine contains important biomarkers that can indicate how a pregnancy is progressing. In this article, we’ll look at some of the key things urine tests can show when a woman is expecting.
HCG levels
One of the first signs of pregnancy that shows up in urine is increased levels of human chorionic gonadotropin, or hCG. This hormone is produced by the placenta shortly after fertilization occurs. It is the hormone detected by home pregnancy tests to give either a positive or negative result.
As pregnancy progresses, hCG levels in the urine continue to rise rapidly, often doubling every 48 to 72 hours in early pregnancy. This increasing concentration is what makes very early pregnancy detectable on urine tests even before a missed period. Doctors can also quantify the exact hCG levels in urine through laboratory testing to:
- Confirm pregnancy and monitor its progress
- Check for potential issues like ectopic pregnancy
- Evaluate the health of the placenta
Normal hCG levels during the first trimester are between 2,700 and 250,000 mIU/mL, peaking between 8 to 11 weeks. Falling hCG levels may be a sign of complications.
Gestational diabetes
Between 24-28 weeks of pregnancy, all women should receive a glucose screening test to check for gestational diabetes. This involves drinking a sugary solution and testing the urine an hour later. Higher than normal glucose levels indicate the need for further testing for gestational diabetes.
If left uncontrolled, gestational diabetes can cause complications like excess fetal growth, so it’s important to diagnose and monitor through urine testing. Women with gestational diabetes need to keep their blood sugar tightly controlled through diet, exercise and possibly medication or insulin.
Protein
Protein in the urine during pregnancy can signal preeclampsia, a serious condition characterized by high blood pressure and other complications. Normal urine contains little to no protein, so detection of significant protein is reason for concern.
Preeclampsia usually develops after 20 weeks of pregnancy in women whose blood pressure was normal. It affects 5-8% of pregnancies and requires close monitoring and sometimes early delivery of the baby. Catching it early through urine analysis allows for proactive treatment to protect mom and baby.
Ketones
Ketones in urine may indicate that the pregnant woman’s body is breaking down fat at an abnormal rate. This may occur in diabetes or excessive vomiting during pregnancy. It’s important to get ketones under control to prevent ketoacidosis, a dangerous buildup of acids in the blood.
A urine dipstick test or lab test can detect ketone levels before they escalate. Treatment involves staying hydrated, controlling blood sugar levels, and modifying diet.
Leukocytes
Leukocytes are white blood cells that enter the urine in response to bacterial infections. If leukocytes show up in the urine during pregnancy, it may mean there is a UTI, kidney infection, chorioamnionitis, or vaginitis.
Left untreated, a UTI can progress to a kidney infection which can trigger preterm labor. So the presence of leukocytes indicates the need for further testing and prompt antibiotic treatment when an infection is present.
Nitrites
Nitrites often accompany leukocytes as evidence of a UTI, which as mentioned is common during pregnancy. Certain bacteria that infect the urinary tract convert nitrates in urine to nitrites. So testing strips that detect nitrites can be used along with leukocyte checks to aid UTI diagnosis and treatment decisions.
Dilution
Pregnant women have increased blood flow and fluid volume, which leads to more diluted urine. This normally does not indicate any problem, but very dilute urine along with excessive thirst may point to gestational diabetes insipidus.
This rare condition occurs when pregnancy hormones interfere with the mother’s normal fluid regulation. Testing urine concentration helps diagnose it so that treatment to restore fluid balance can be implemented.
Signs of dehydration
Dehydration is common in pregnancy due to expanded blood volume, morning sickness, and increased urination. The color, smell or volume of urine can quickly indicate if a pregnant woman needs more fluids.
Concentrated, dark yellow or orange urine, strong odor, and infrequent urination signal inadequate hydration. Up water intake is an easy fix to keep both mother and developing baby healthy.
Preterm labor
The presence of certain chemicals and compounds in urine can sometimes predict the risk of going into preterm labor. Specific proteins and changes in microbiota can be detected and measured through urine specimens.
While not definitive, these early clues allow closer monitoring when preterm birth is likely so that interventions can be made to delay delivery where possible. Researchers continue to investigate urine’s potential for more precise and earlier preterm birth prediction.
Protein/Creatinine Ratio
This urine test calculates the levels of protein against creatinine which is a waste product in the blood. Higher than normal protein levels compared to creatinine could indicate preeclampsia or other complications.
Bacteria
A urine culture is a test that incubates a urine sample to allow any bacteria present to multiply. This makes it easier to identify the specific bacteria causing a suspected UTI. Knowing the bacteria and its susceptibilities guides effective antibiotic selection.
pH Levels
Urine pH normally varies throughout the day from around 4.5-8. During pregnancy, a urine pH consistently under 5.5 in a clean-catch urine sample could signal renal tubular acidosis resulting from pregnancy hormonal shifts. Testing pH helps detect acidity issues.
Specific Gravity
This is a general measure of how concentrated urine is. Low specific gravity indicates very diluted urine, while high levels mean concentrated urine. Abnormal readings could reflect hydration issues, diabetes insipidus, or other concerns.
Conclusion
Urine contains many clues about maternal and fetal health during pregnancy. Regular urine testing allows early detection of risks like infections, preeclampsia, gestational diabetes, dehydration and preterm labor. Knowing what urine tests look for guides pregnant women and their healthcare providers in identifying and promptly addressing developing issues for the best pregnancy outcomes.
| Urine Test | What it detects |
|---|---|
| hCG | Pregnancy hormone levels |
| Glucose | Gestational diabetes |
| Protein | Preeclampsia |
| Ketones | Complications from diabetes or vomiting |
| Leukocytes | UTIs or other infections |
| Nitrites | UTI bacteria |
| Concentration | Hydration status |
| Color | Hydration and concentration |
| Proteins | Risk of preterm birth |
| Creatinine Ratio | Kidney function and preeclampsia signs |
| pH | Acidity imbalances |
| Bacteria | UTI microorganism identification |
| Specific gravity | Concentration and hydration |
