Pregnancy of unknown location (PUL) is defined as the situation when the urine or serum pregnancy test is positive but there are no signs of intrauterine or extra-uterine pregnancy on ultra-sonography and serum beta HCG is in the window period. Among all possible outcomes of pregnancy of unknown location, ectopic pregnancy is the most feared outcome. A delay in diagnosis might increase the maternal mortality and morbidity.
Methods: A prospective observational study conducted at Sri Ramachandra Institute of Higher Education and Research, Chennai, between February 2018 and April 2019. Women who had beta HCG in the discriminatory zone with an inconclusive transvaginal ultrasound were included in the study. Serum Creatinine phosphokinase levels were measured along with beta HCG.
Results: Among the 12women with PUL, 11 of them were eventually diagnosed with ectopic gestation and one of them remained to be a pregnancy of unknown location. All the patients diagnosed with ectopic gestation had their initial serum CPK levels above the cut off value of 51IU/lit.
Conclusion: Serum CPK levels in PUL can be used as a marker for early diagnosis of ectopic gestation when beta HCG and ultrasound are inconclusive. Larger studies are required to ascertain the significance.