Specific gravity test requirement for Urine Pregnancy testing for OR patients

hmm, 100+ views, not a single reply... 

Hello Alexandr
We use Sure-Vue Urine pregnancy tests (waived) in our preop area. MAs or RNs performs urine pregnancy testing with no specific gravity requirements as it's a point of care test. Follow the manufacturer's directions for QC and the internal QC monitors are charted along with patient results.  We only get serum specimens from this site if an invalid or questionable result (faint line at T) is obtained.
Main chemistry lab uses the Sure-Vue Combo (urine- waived & Serum - moderate) kits that do serum and urine. Urine PT performed in the lab have a specific gravity because it's being performed in the lab which doesn't make much sense but that's how our director wants it.
The lab actually tests specific gravity on ALL urine pregnancy tests they perform regardless of where the specimen was collected or the result. Performing 2 manual tests in 2 departments in time consuming and I think unnecessary particularly in our short staffed environment..

I can only assume you have similar verbiage for the kits you are using -  "Very dilute urine specimens, as indicated by a low specific gravity, may not contain representative levels of hCG. If pregnancy is still suspected, a first morning urine specimen should be collected 48 hours later and tested."  One of the problem   is that the company doesn't state what the low threshold would be.  This statement is true for all urine pg tests so should everyone switch to serum pgs for preops????
Our chemistry supervisor and I have tried to change the directors mind regarding this issue but he's standing fast.  

Hopefully you can convince your director to make this change.
Good Luck

Thank you Amanda for your response. We are using Icon kits, which are most likely have the same methodology as Sure-Vue. 

We do the same as Amanda. Historically for us, the hospital was sued for reporting a negative urine preg and not checking the specific gravity. Turns out the sp gravity was <1.010, the patient was early pregnant and had a radiology procedure. A serum pregnancy test may have picked it up. 

We use the Clinitek Status for urine preg's.  We do not perform specific gravity with the POC testing.  We do have dilute urine <1.010 as a limitation.

Thank you Terry and Miranda!

Our hospital preop areas do a urine preg test, no spec. gravity is tested. I tried to get some interest in doing a blood test instead, to no avail. Terry Rose's comment about a lawsuit is concerning.

We perform urine pregnancy testing in our pre-op and outpatient surgery departments.  We do not perform a specific gravity on the specimen.

Terry Rose, you didn't tell us if the suit was successful. I think it's well known that urine pregnancy tests have limitations, so I'm not sure that's a suit that can be won. 
We do urine pregnancy via several kits depending on the site, and on the Clinitek at our ED/UC sites. We do not do specific gravity for any POCT urine pregnancy test. 

Cathy, Stephanie and Kathleen, thank you for your responses. Would you mind sharing your main rationale for not using a specific gravity test for negative pregnancy tests? As I understand this, the vendors (ICON 20 hCG) do not require sp.gravity test to confirm the negatives and, there are some studies performed, which shows that all modern rapid immunoassays are sensitive enough to detect early pregnancy even in low sp.gr. samples. 

Alexandr, the main reason not to do specific gravity is that it would require doing a urine dipstick to get the specific gravity. It's not required in the IFU for any of our urine pregnancy tests, and I don't believe it would be reimbursed if the clinician didn't order a urine dipstick test. When we've had complaints, mostly when the urine pregnancy is negative but the beta hCG is positive, we remind the clinician of the limitations of the urine pregnancy test, especially in early pregnancy, and let them know to go with the blood test. 

Hi Alexandr. I would agree with Kathleen and the reasons she stated for not performing a urine SG on negative urine pregnancy tests.  This practice is not required in our IFU.  If the urine pregnancy result is in question, we always tell them to order a beta hCG to confirm the value.