Early urinary pregnancy testing. Correlation with serum beta-HCG radioimmunoassay

Urinary pregnancy testing with Sensitex, a tube macroflocculation system, produced a positive test by 17 days after basal-body-temperature-timed ovulation in 59% of determinations. Data from days 18 to 21 showed that a negative test was associated with a statistically significantly increased propensity for first-trimester abortion. Freezing of the urinary specimens, but not refrigerated sm, produced a positive test by 17 days after basal-body-temperature-timed ovulation in 59% of determinations. Data from days 18 to 21 showed that a negative test was associated with a statistically significantly increased propensity for first-trimester abortion. Freezing of the urinary specimens, but not refrigerated storage for five days, adversely affected the accuracy of the test.