The Collaborative International Dictionary of English v.0.48:

Uterine \U"ter*ine\ (?; 277), a. [L. uterinus born of the same
   mother, from uterus womb: cf. F. ut['e]rin.]
   [1913 Webster]
   1. Of or instrument to the uterus, or womb.
      [1913 Webster]

   2. Born of the same mother, but by a different father.
      [1913 Webster]

            Walter Pope, uterine brother to Dr. Joh. Wilki??.
                                                  --Wood.
      [1913 Webster]

WordNet (r) 3.0 (2006):

uterine
    adj 1: of or involving the uterus; "uterine cancer"

Moby Thesaurus II by Grady Ward, 1.0:

43 Moby Thesaurus words for "uterine":
   affiliated, agnate, akin, allied, avuncular, cervical, clitoral,
   closely related, cognate, collateral, congeneric, consanguine,
   consanguinean, consanguineous, distantly related, enate, foster,
   genital, german, germane, kindred, matrilateral, matrilineal,
   matroclinous, novercal, of the blood, ovarian, patrilateral,
   patrilineal, patroclinous, penial, penile, phallic, related,
   scrotal, seminal, sib, sibling, spermatic, testicular, vaginal,
   vulval, vulvar