AMAG Pharmaceuticals, Inc announced the issuance of U.S. Patent Number 9,844,558 entitled “Methods of Reducing Risk of Preterm Birth.” This newly issued patent is directed to subcutaneous administration and dosing of Makena® (hydroxyprogesterone caproate injection) and is expected to expire on May 2, 2036. Makena is a treatment to reduce the risk of preterm birth in women who are pregnant with one baby and who spontaneously delivered one preterm baby in the past.