Abstract: An intrauterine device (IUD) with a restricted movement of a string(s), the strings can be either a single string or two or more strings or a filament, emerging from the spherical bulge of IUD. The strings of IUD are of a differential strength so that the strings are soft and the hanging portion of the strings, “feelable” in the vaginal cavity, does not cause discomfort to the woman, nor bruise the organ of the partner during intercourse, at the same time the strings in the endocervical canal are relatively stiffer and not have the tendency to get curled up progressively. The strings optionally have marks to facilitate cutting by a surgeon to an accurate length.

Abstract: An intrauterine device (20) with a restricted movement of a knot (5) of the string (4) due to a region (3) having such differed shape and size at a distal end (12) of central vertical stem (1) and due to a trajectory for string (4) in the region (3) that the length of the string (S) is shorter than the distance (r) of the region (3); and the loop (15) of the string and therefore the knot (5) is unable to pivot around the axis (14) . The lateral shift of the knot (5) is also prevented. Consequent to restricted pivoting and restricted lateral shift of the knot (5), the hanging portion (9) of the string (4) continue to project downwards and do NOT develop tendency to get retracted and thus do not curl up in the uterus (16) through the cervix (17).

Abstract: An intrauterine device (IUD) with a restricted movement of a string(s), the strings can be either a single string or two or more strings or a filament, emerging from the spherical bulge of IUD. The strings of IUD are of a differential strength so that the strings are soft and the hanging portion of the strings, “feelable” in the vaginal cavity, does not cause discomfort to the woman, nor bruise the organ of the partner during intercourse, at the same time the strings in the endocervical canal are relatively stiffer and not have the tendency to get curled up progressively. The strings optionally have marks to facilitate cutting by a surgeon to an accurate length.

Abstract: An intrauterine device (20) with a restricted movement of a knot (5) of the string (4) due to a region (3) having such differed shape and size at a distal end (12) of central vertical stem (1) and due to a trajectory for string (4) in the region (3) that the length of the string (S) is shorter than the distance (r) of the region (3); and the loop (15) of the string and therefore the knot (5) is unable to pivot around the axis (14). The lateral shift of the knot (5) is also prevented. Consequent to restricted pivoting and restricted lateral shift of the knot (5), the hanging portion (9) of the string (4) continue to project downwards and do NOT develop tendency to get retracted and thus do not curl up in the uterus (16) through the cervix (17).