Urine Pregnancy Test Research Articles

Performances of Urine Pregnancy Tests on College of American Pathologists’ Survey Specimens

Pregnancy tests for human chorionic gonadotropins (hCG) in urine has yielded false-positive and false-negative results. The technical error rate in performing pregnancy tests is 1-4%. This paper presents the results of participant tests on the CAP (College of American Pathologists) Survey specimens. In 1979 and 1980 the CAP prepared 22 urine survey specimens for hCG testing. Radioimmunoassay was used to determine reference levels of hCG in these specimens. 8 negative specimens contained no hCG 8 low-level specimens contained 0.6-1.0 U/ml and 6 high-level specimens contained 2.2-3.8 U/ml. Laboratories participating in the CAP Urine Survey Program received and tested these specimens for the presence of hCG using their reagent products of choice and recorded their results as positive or negative. The CAP Computer Center tabulated the results as correct or incorrect according to the assayed levels of hCG within the specimens. 35014 hCG tests were performed. 58.9% were determined by slide procedures and 41.1% were determined by tube procedures. Correct results were obtained in 88.2-99.3% of participant tests. Correct results were obtained in 70.8-100% of participant tests on urine specimens containing high levels of hCG (2.2-3.8 U/ml) and in 2.2-96.4% of participant tests on urine specimens containing low levels of hCG (0.6-1.0 U/ml). This study shows that almost all the reagent methods used by participants performed well on the negative specimens. 2 major factors affect the performance of results with various urine pregnancy tests: 1) the sensitivity of the test for hCG detection and 2) the level of hCG in the specimen. Laboratory workers should develop a high level of awareness of the reagents sensitivity limitations and capabilities of commercial tests for urine hCG.

False-Positive Radioimmunoassay Pregnancy Test in Nephrotic Syndrome

THE TECHNIQUE of radioimmunoassay (RIA) is currently the most popular method for measurement of hormone levels in plasma or serum. Radioimmunoassay combines excellent sensitivity with precision and freedom from interference. However, subtle differences in RIA procedures can make a substantial difference in the reliability of this technique on serum or plasma samples from nephrotic patients. We report a case that shows repeated false elevations of β-human chorionic gonadotropin (β-HCG) levels during a period of nephrosis. Report of a Case A 17-year-old girl was seen because of gross edema of one to two weeks' duration. There was no history of renal disease or a recent known precipitating event. Her last menses had been approximately three months previously, and there had been at least one subsequent exposure to pregnancy. Urine pregnancy tests of unknown type done elsewhere during the previous week were said to be positive. Examination revealed generalized edema, with a

False-Positive Radioimmunoassay Pregnancy Test in Nephrotic Syndrome

THE TECHNIQUE of radioimmunoassay (RIA) is currently the most popular method for measurement of hormone levels in plasma or serum. Radioimmunoassay combines excellent sensitivity with precision and freedom from interference. However, subtle differences in RIA procedures can make a substantial difference in the reliability of this technique on serum or plasma samples from nephrotic patients. We report a case that shows repeated false elevations of β-human chorionic gonadotropin (β-HCG) levels during a period of nephrosis. Report of a Case A 17-year-old girl was seen because of gross edema of one to two weeks' duration. There was no history of renal disease or a recent known precipitating event. Her last menses had been approximately three months previously, and there had been at least one subsequent exposure to pregnancy. Urine pregnancy tests of unknown type done elsewhere during the previous week were said to be positive. Examination revealed generalized edema, with a

Urinary Immunoassay Pregnancy Test is Found Quick, Cheap, Accurate

Urinary Immunoassay Pregnancy Test is Found Quick, Cheap, Accurate

Use of a rapid radioimmunoassay for pregnancy-specific beta-1 glycoprotein in gynecologic emergencies: Comparison with routine urinary pregnancy test and a rapid radioimmunoassay for human chorionic gonadotropin

The use of a rapid test for pregnancy-specific beta-1 glycoprotein (SP1) in emergency patients is described and the results of using this test on 141 women with gynecologic emergencies are presented. Serum samples were obtained from 141 women of reproductive age with lower abdominal pain or vaginal bleeding. The radioimmunoassay for SP1 used only 1 standard consisting of pregnancy serum diluted with normal female serum to give an SP1 concentration of 20 mcgm/liter. Serum (undiluted) was incubated with anti-SP1 antiserum diluted to yield 30% binding in zero standard and iodinated SP1 at 37 degrees centigrade for 3 hours. Antibody-bound material was precipitated and the result was judged positive if radioactivity in the precipitate was less than that in the reference tube. Results were compared with routine urinary pregnancy tests and rapid serum human chorionic gonadotropin beta subunit radioimmunoassay. Clinical/histological evidence of complicated intrauterine or ectopic pregnancy was found in 38 patients (27%). Rapid SP1 radioimmunoassay was positive in 18% of all patients rapid chorionic radioimmunoassay was positive in 24% and urinary tests were positive in 7%. 17 patients had verified ectopic pregnancy and among these cases 59% were positive by SP1 23% by urinary test and all 17 patients were positive by chorionic gonadotropin.

Radioimmunoassay of human chorionic gonadotropin beta-subunit as an early diagnostic test in ectopic pregnancy.

Serum HCG-beta has been assayed in 100 cases of ectopic pregnancy. Results above 10 IU/l were considered positive. Positive values were found in 97 cases, of which 23 were within the range of a normal pregnancy, one was above and 73 below the normal range. In the 3 cases with a negative HCG-beta value, devitalized ectopic pregnancies were found at operation. The routine urine pregnancy test was negative in 53, positive in 29 and not performed in 18 cases.

Competing Risks of Unnecessary Procedures and Complications

With early treatment of menstrual regulation, the probability of performing an unnecessary operation in quite high. Pregnancy tests available that are sufficiently sensitive to confirm an early pregnancy are beyond the financial reach of many clinics and hospitals. It is difficulty to justify performing procedures for patients with relatively insensitive negative pregnancy tests. However, there are occasions where the procedure must be done without delay. The total number of women considered was 14,716 of whom 12,888 reported a delay in menstruation of 1-14 days and 1828 reprted a delay longer than 14 days. Urinary pregnancy tests were done for all. The uterine aspirate was examined for pregnancy evaluation. The false positive rate was 7% and the false negative rate 42.3%. The probability of pregnancy increased with the time of delay in menstruation. At the end of the 3rd week of delay the probability of pregnancy was about 90%. Repeat curettage for heavy bleeding or retained products was the most serious complication. The rate of significant complications was twice as high when pregnancy was present. Of the 12,888 reporting menstrual delay not over 14 days, 29.1% were not pregnant and 3.9% had significant complications.

Endometrial aspiration in fertility control: A report of 500 cases

Outpatient endometrial aspiration was offered to patients who suspected that they were pregnant, but were within 5 to 21 days after failure of expected menstruation and had a uterus of normal size on pelvic examination. This is a report of 500 consecutive cases treated between September 1973, and April 1975. Histologic examination of the aspirated tissue was obtained on all 500 cases (100 per cent). Follow-up examination and urine pregnancy test at 2 weeks were obtained on 407 patients (81.4 per cent). Histologic evidence of pregnancy was obtained in 323 patients (64.6 per cent). Complications were limited to five infections (1 per cent), only one of which led to hospitalization of the patient, and failure to completely evacuate the pregnant uterus in 39 patients (12.1 per cent of the 323 pregnant). Thirty-four of these had the uterus emptied by a second outpatient procedure and five patients were hospitalized to complete their abortion.