Objective To determine circulating levels of placental protein 14 (PP14) in complications of early pregnancy.

Design Biochemical monitoring of women presenting with vaginal bleeding and/or abdominal pain.

Setting An emergency gynaecological ultrasound clinic in a London teaching hospital.

Subjects Venous blood samples were obtained from 67 women with normal pregnancy (n= 9), ectopic pregnancy (n= 26) and failed intrauterine pregnancy (n= 32). This group included anembryonic pregnancy (n= 18), missed miscarriage (n= 2), spontaneous miscarriage of a previously demonstrated live fetus (n= 6), incomplete miscarriage (n= 4), complete miscarriage (n= 1) and molar pregnancy (n= 1).

Main outcome measures Serum PP14 levels in the group of women with a failed intrauterine pregnancy in relation to the normal range for PP14.

Results Eighty-one percent of women who miscarried spontaneously had normal serum PP14 levels; 81% of women with ectopic pregnancy had depressed (< 5th centile) serum PP14 levels.

Conclusion Measurements of PP14 may be useful in distinguishing spontaneous miscarriage from ectopic pregnancy, but not in the management of threatened miscarriage.