A Two and Six-Hour Pregnancy Test1

Abstract

A preliminary report is presented on a 2- and 6-hr. pregnancy test employing rats of almost any age and wt. The 2-hr. test is based upon the hyperemic effect of urinary gonadotrophins upon the ovary and ovarian capsule noted 2 hrs. after intraperitoneal inj. of 1.5 ml. of urine into immature [female] rats in divided doses of 3/4 ml. each. The rats may be of any age (21-55 days) or wt. (30-100 g.) providing vaginal introitus or corpora lutea formation has not occurred. The 6-hr. test may be performed on ? rats of any age or wt. In the immature rats (similar to those used for the 2-hr. test) the end reaction is the hyperemic effect of the urinary gonadotrophin upon the ovary and ovarian capsule. The diagnostic feature in the adult animal is the vascularizing effect of pregnancy urine upon the corpora lutea of animals injected when in diestrus or metestrus. Of 33 specimens of urine from non-pregnant individuals, there was no instance of a false positive reaction. Only 2 of 48 samples of pregnancy urine gave an indecisive reaction, but the urines from these patients yielded strongly positive reactions 5 days later. In performing the test 3 rats are sufficient, 2 for the 2-hr. test and 1 for the 6-hr. test. However, if necessary, only 1 animal may be used if the test is positive, but in instances of a negative test it is advisable to inject at least 2 more animals for confirmatory data.