Expectant management of early pregnancies of unknown location: a prospective evaluation of methods to predict spontaneous resolution of pregnancy

Objective To assess prospectively the ability of two multiparameter diagnos tic models and their individual components to predict the outcome of early pregnancies which could not he identified on transvaginal ultrasound scan. Design Prospective observational study. Setting Dedicated early pregnancy unit in an inner city teaching hospital. Population Women with a positive urine pregnancy test: and clinical suspici on of early pregnancy complications. Methods A full medical history, clinical examination and transvaginal ultra sound scan were carried out at the initial visit. When the location of the pregnancy could not be ascertained by ultrasound, serum beta-human chorioni c gonadotrophin (beta -hCG) and progesterone levels were measured. All wome n were managed expectantly until either a normal pregnancy was visualised o n scan; the pregnancy resolved spontaneously or intervention was required d ue to a worsening of clinical symptoms or non-declining beta -hCG levels. Main outcome measures Spontaneous resolution of pregnancy (i.e. cessation o f symptoms and decline in serum beta -hCG level to < 20 iu/L) without need for any active intervention. Results Of the 104 women recruited, 72 (69%) pregnancies resolved spontaneo usly. Both multiparameter diagnostic models identified resolving pregnancie s with positive predictive values greater than or equal to 95%. Their perfo rmances were not significantly better compared with individual progesterone levels which achieved a positive predictive value of 97% using a cutoff le vel of 20 nmol/L. Conclusion Serum progesterone measurement alone is as accurate as more samp les diagnostic models for the prediction of successful expectant management in pregnancies of unknown location.