It is likely that every reader of this blog has had this unnecessary procedure done routinely. At every prenatal visit, be it with an OB or with a midwife, urine dipstick testing is performed. Yet the evidence to support this procedure is scanty.
You might say “So what if there’s not evidence to support routine urine dipstick testing? It’s not invasive, so what’s the harm?”
Tests that are run unnecessarily do pose problems:
- They cost money–whether this is paid for by private insurance, Medicaid, or the patient herself, an unnecessary urine test drives up healthcare costs–something none of us can afford
- They have a high rate of false-positives. This means that the test results say something is wrong, so further testing is ordered, and it’s found that nothing is wrong at all. For glucose (sugar) screening, false positives outnumber true positives 11:1.¹ Urine is dipped for protein in order to determine if pre-eclampsia is beginning, but testing by this method is accurate only 2 – 11% of the time.²
So is urine testing ever indicated? Yes, there are three situations in which urine testing is advised:
- An initial urine test at the first prenatal visit, to screen for urinary infection without symptoms
- Urine dipstick testing targeted for women with high blood pressure prior to pregnancy, increased blood pressure during pregnancy, multiple gestations, or acute weight gain.³
- Dipstick may be used for women with suspected gestational diabetes, but as the diagnostic test for gestational diabetes is the glucose test, dipstick usefulness is doubtful. Sugar is found in the urine at some point in pregnancy in about 50% of women, but is not a good predictor of gestational diabetes. Sugar in the urine may be a result of normal physiological changes of pregnancy. Four studies assessed the value of sugar in the urine as a screening for gestational diabetes, and all four concluded there was no evidence for routine urine dipstick testing.4
The American Congress of Obstetricians and Gynecologists does not recommend routine urine dipstick screening because it is not “reliable and cost-effective”5
One government agency summarized the findings this way:
Reliance on routine dipstick urine testing to diagnose pre-eclampsia, diabetes, and asymptomatic urinary tract infections is fraught with difficulties. The basic modality is both insensitive and non-specific. In addition, it is difficult to obtain an actual clean catch specimen on every visit from increasing gravid women. Here are better approaches for screening
-Gestational diabetes with oral glucose screening
-Pre-eclampsia with blood pressure
-Asymptomatic bacteriuria [urine infection with no symptoms] with a culture at the first visit
In the meantime, I suggest your precious health care resources be used elsewhere. It will also help the flow of your prenatal visit not to have each patient have to get unnecessary urine that then has to be run your otherwise busy staff.5
So, the common-sense tip for today: take a copy of this blog post to your provider and decline that routine urine dipstick test.
1. Watson WJ. Screening for glycosuria during pregnancy. Southern Med J 1990;83:156–158.
2. Saudan PJ, Brown MA, Farrell T, Shaw L. Improved methods of assessing proteinuria in hypertensive pregnancy. Brit J Ob Gyn 1997;104:1159–1164.
3. American College of Obstetricians and Gynecologists. ACOG Practice Bulletin 33. Diagnosis and management of preeclampsia and eclampsia. Washington, DC: ACOG; 2002;312–320.
4. No need for routine glycosuria/proteinuria screen in pregnant women. Retrieved 12/19/09 from: http://www.jfponline.com/pages.asp?aid=2812&UID=
5. ACOG practice bulletin #33. Retrieved 12/19/09 from https://access.acog.org/eweb/DynamicPage.aspx?WebCode=LoginRequired&Site=ACOG&urlReq=/publications/educational_bulletins/pb033.cfm
6. Urine prenatal testing. Retrieved 12/19/09 from http://www.ihs.gov/medicalprograms/mch/m/documents/UrinPrenat9405.doc
I find this very interesting, I knew from personal experiance that the sugar level reported in the urine dip doesn’t mean much, but I didn’t know that the protein level was so unreliable as well. My midwife first birth had me dip a urine every time (I read it myself though so no busy staff to bother). I figured that the $10 bottle of 100 strips was a cost effective way to test for potential life-threatening issues, but when you add in all the unnecessary testing done due to false positives, I see how it can waste a lot of money!
My CNM for my second pregnancy doesn’t do routine urine dips. It was a relief not to feel like I had to make sure that I had filled up my bladder just before coming to an appointment, especially at the end when she was doing a cervical check every time. Makes sense to me to not bother if there are more accurate ways of diagnosing the potential complications.
Good for her! This is often frustrating for the woman who “can’t go” or, as you noted, has to hold it until the right time. Added to this is the increasing difficulty working around a big belly to obtain a clean-catch specimen.
You forgot one other disadvantage of routine urine specimens, the cost to the environment. How many of those plastic urine cups are now in landfills? Seriously, medical waste is a real problem.
I actually tried to get our L&D unit to decrease the routine urine screen. It would have saved our unit and the patients over $10,000 a year just in plastic cups! (I did not even include the lab cost).
Excellent point!
I had so many issues I cared about–I refused AFP blood testing and glucose testing and sonograms…at some point I had to decide how much I wanted to protest. With some practitioners this would definitely be worth doing, but with others, this might not be the battle to pick.
Ideally, these issues would not even be argued with you. I believe that a list of all routine tests, procedures, etc., should be provided to the client at the first visit. Along with the list should be information detailing the available evidence about the test/procedure. The client should be able to check off the ones she wants and eliminate the ones she does not. Simple as that.
I totally agree. I went to a great session about this exact topic at an ACNM conference a few years ago, went back to the birth center where I was working at the time and changed the protocol so we no longer did urine dips as a routine measure. When I moved to a home birth practice, I changed the protocol there, too. I know many CenteringPregnancy groups also do not do routine dips. Hopefully the word is getting out, but slowly as with everything else.
Great post!
Unfortunately, I’m finding it’s difficult to convince most people to change their practices. The attitude seems to be that it’s not invasive or harmful, so why change? With the major problems we have with health care costs today, I think we need to be looking for any legitimate ways we can cut costs without compromising quality of care.
Exactly Janelle!
With 4 million women having 14 prenatals on average per pregnancy each year…52,000,000 strips. If the bottle of strips really costs $10 per 100 strips, that is $5.2 million per year. Every “little” bit of savings counts.
This leaves out the cost of the time spent by medical staff ordering the strips, keeping them stocked, doing the dip; the cost of the cups that are used (some practices use the hard plastic urine specimin cups, while others use paper cups), the cost of waste disposal…
Amazing! Thanks for submitting these figures; it really makes it hit home what a waste this is.
A proportion of women with pre-eclampsia develop new proteinurea in pregnancy before any sign of hypertension, and can be seriously unwell by the time hypertension develops.
Women can be taught to give a clean catch directly on the stick (quick localized ‘wash’/wipe, void, pee on stick, finish void, bring stick to HCP) – thereby avoiding much of the medical waste discussed here. I don’t think asking someone to pee on a stick is any more invasive than taking a BP, abdominal palpation, listening in at antenatal appointments (why do it? If you have fetal movements, what do you learn by listening in? Certainly we learn more useful information from a dipstick).
Totally agree about glucose though, and wouldn’t even use the dipstick in case of increased diabetes risk or symptoms – I would go straight to OGTT for that. But I would still want to test for protein with a dipstick. Also, I would send an MSU to the lab for cultures if I picked up leucocytes on a dipstick.
I agree with you that using just a stick for a sample would save money, and certainly a urine test itself is not invasive.
However, the evidence in the references I listed on this post does not support routineurine testing. It was found that proteinuria alone was not predictive of pre-eclampsia, and could occur for several other benign reasons. The studies’ conclusions were that there was no indication of benefit from routine antenatal urine screening.
Current US standards define pre-eclampsia as the new onset of high blood pressure after 20 weeks’ gestation with proteinuria. Proteinuria alone is not diagnostic of pre-eclampsia. Because of the diagnostic criteria requiring both proteinuria and hypertension, I tend to concur with the conclusion of the studies which state one urine sample should be tested at the beginning of pregnancy, and thereafter, only if the woman has symptoms of urine infection or developing high blood pressure.
Reference for definition of pre-eclampsia:
Sibai BM. Hypertension. In: Gabbe SG, Niebyl JR, Simpson JL, eds. Obstetrics – Normal and Problem Pregnancies. 5th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2007:chap 33.