Intrauterine contraceptive device

Abstract

An integral intrauterine contraceptive device comprises a relatively thick elongated stem, a downwardly bowed crossbar secured to the top of the stem, and a pair of downwardly and inwardly extending arms formed as continuations of the crossbar. The crossbar and arm construction is designed for atraumatic embedding in the endometrium to reduce expulsion caused by uterine contractions.

What is claimed is: 
     
       1. An intrauterine contraceptive device comprising: a. an elongated stem having an upper portion and a lower portion.[.;.]..Iadd., said stem upper portion having a thickness of between 4.0 to 6.0 mm as measured in a plane perpendicular to the anterior and posterior walls of the endometrium when the device is inserted in the uterus; .Iaddend.   b. a resilient downwardly bowed crossbar integrally secured at its midpoint to the tip of said stem upper portion; and   c. a pair of resilient arms formed as integral continuations of the opposed ends of said crossbar, said arms being angled downwardly and inwardly toward said stem and terminating short of touching said stem, and the line of each of said arms defining an included angle with the central axis of said stem of between 40° and 70°. .[.2. A device as claimed in claim 1 wherein said stem upper end has a thickness of between 4.0 to 6.0 mm as measured in a plane perpendicular to said crossbar to provide such thickness in a plane perpendicular to the anterior and posterior   
     
     
        walls of the endometrium when the device is inserted in the uterus..]. 3. A device as claimed in claim .[.2.]. .Iadd.1 .Iaddend.wherein said 
     
     
        thickness is 4 mm. 4. A device as claimed in claim 1 wherein said included 
     
     
        angle is on the order of 50°. 5. A device as claimed in claim 1 wherein said arms include flat fin portions at their ends oriented to 
     
     
        reduce tissue penetration of said arms during use of said device. 6. A device as claimed in claim 1 wherein said arms are angled in opposite directions out of the central plane through the stem and crossbar adapting said arms to cross over and slide by said stem during insertion of the 
     
     
        device. 7. A device as claimed in claim 6 wherein each said arm is angled 
     
     
        out of said plane by an angle on the order of 10°. 8. A device as claimed in claim 7 including a pair of crossbar extensions forming a continuation of said crossbar beyond the point of intersection of said arms and said crossbar and adapted to provide additional embedding of said 
     
     
        device during use thereof. 9. A device as claimed in claim 1 wherein said stem is on the order of 20 mm in length and said crossbar spans a distance on the order of 30 mm and has a radius of curvature on the order of 30 mm. 
     
     
        0. An intrauterine contraceptive device adapted to lie in the fold between the anterior and posterior walls of the endometrium comprising: a. an elongated stem having a lower portion and an upper portion, said upper portion having a thickness between 4.0 to 6.0 mm in a direction perpendicular to the anterior and posterior walls of the endometrium with said device installed therebetween and said lower portion having an outside diameter adapted for being slidably received by an inserter tube;   b. a resilient downwardly bowed crossbar integrally secured at its midpoint to the tip of said stem upper portion; and   c. a pair of resilient arms formed as integral continuations of the opposed ends of said crossbar, said arms being angled downwardly and inwardly toward said stem and terminating short of touching said stem, and the line of each of said arms defining an included angle with the central axis of said stem of between 40° and 70°, said arms having flat fin-like portions at the ends thereof oriented to reduce tissue penetration during use thereof, and said arms being angled in opposite   
     
     
        directions out of the central plane through the stem and crossbar. 11. A device as claimed in claim 10 wherein said upper stem portion thickness is 
     
     
        4 mm. 12. A device as claimed in claim 11 wherein said included angle is 
     
     
        on the order of 50°. 13. A device as claimed in claim 12 wherein each said arm is angled out of said plane by an angle on the order of 
     
     
        10°. 14. A device as claimed in claim 13 wherein said stem is on the order of 20 mm in length and said crossbar spans a distance on the order of 30 mm and has a radius of curvature on the order of 30 mm. .Iadd. 15. An intrauterine contraceptive device comprising: (a) an elongated stem having an upper portion and a lower portion, said stem upper portion being of non-circular cross section and having a thickness of between 4.0 to 6.0 mm as measured in a plane perpendicular to the anterior and posterior walls of the endometrium when the device is inserted in the uterus between said walls; and   (b) a foldable, flexible arm structure depending from said upper portion of said stem and formed in a shape to provide atraumatic embedding in the anterior and posterior walls of the endometrium and to resist expulsion during contraction of the fundus. .Iaddend.