The Difference Between a Qualitative and Quantitative Pregnancy Test?

Answer 1

A pregnancy test can be performed early in pregnancy to predict conception or gestational age. Urine-based pregnancy tests detect pregnancy hormones in urine for a positive or negative result. Blood tests measure how much of a pregnancy hormone is present.

Qualitative Pregnancy Test – Urine

Home pregnancy test kits and urine pregnancy tests given by a physician are qualitative. Qualitative refers to the method of diagnosing pregnancy. Urine tests measure the presence of human chorionic gonadotropin (hCG) in urine. If hCG is present, the test results are positive. If no hCG is found in urine, the test will be negative.

False negatives are more common with a urine pregnancy test than false positives. False negatives can be caused by frequent urination due to high fluid intake and miscalculated start day of current menstrual cycle. False positives are typically linked to fertility treatments and prescription medications that include hCG as a means of increasing chance of conception.

Quantitative Pregnancy Test – Blood

A blood pregnancy test can be ordered as early as five to 10 days after unprotected intercourse. Blood pregnancy tests measure hCG levels in quantity rather than just a true or false result. Quantities can then be compared to normal levels as a means of gestational age prediction. In some cases, quantitative pregnant test results are higher than normal. Normal hCG levels at five weeks gestation fall between 18 and 7,340 mlU / ml. Measurements at the higher end of the range could mean medical issues with the pregnancy or multiple fetuses. Blood hCG levels will continue to rise until peaking between nine and 12 weeks gestation. After the 12th week, levels gradually fall until birth.

Medical Treatment and Pregnancy Test

Due to the possibility of false negative pregnancy test results, women who believe they may be pregnant should exercise caution when taking prescription and over the counter medications deemed unsafe during pregnancy. Diagnostic testing, such as X-rays and radiation-based testing should only be performed when medically necessary. Precautions include lead aprons placed over the abdominal area during X-rays. Prescription medications fall into pregnancy categories based on clinical testing and results. Categories include A, B, C, D and X.

Category A drugs have been thoroughly tested for use during pregnancy and deemed safe. Category B is designated after animal testing revealed no signs of fetal harm. Category C may be linked to fetal damage in animal testing. Category D includes drugs proven to cause harm to a human fetus, but benefits from medications in this category could outweigh risks. Category X is reserved for medications that should never be used during pregnancy.