Use of serum progesterone measurements to reduce need for follow-up in women with pregnancies of unknown location.

OBJECTIVE

To assess the efficacy of a progesterone-based algorithm for the management of women with pregnancies of unknown location (PULs) and explore the feasibility of developing a single-visit strategy in those with a low risk of requiring medical intervention.

METHODS

All clinically stable women in whom pregnancy could not be identified on ultrasound scan were managed by a pre-defined protocol based on measurement of serum progesterone and beta-human chorionic gonadotropin (beta-hCG). Intervention in the form of surgery or medical treatment with methotrexate was offered to all women with persistent or worsening symptoms and non-declining serum beta-hCG. Decision-tree analysis was used to develop a protocol for the management of women with resolving pregnancies who are at low risk of requiring medical intervention.

RESULTS

1110 women were included in the data analysis: normal intrauterine pregnancy was diagnosed in 248 (22.3%; 95% CI, 19.9-24.8) women. 761 (68.6%; 95% CI, 65.8-71.3) abnormal pregnancies resolved spontaneously on expectant management, while the remaining 101 (9.1%; 95% CI, 7.4-10.8) women with abnormal pregnancies required some form of medical intervention. Intervention rates in patients presenting with initial serum progesterone levels of <or= 20 nmol/L and <or= 10 nmol/L, were 3.9% (95% CI, 2.4-5.4) and 2.1% (95% CI, 0.9-3.3), respectively. In women presenting with progesterone <or= 10 nmol/L and beta-hCG < 450 IU/L, the intervention rate was 1.3% (95% CI, 0.2-2.5).

CONCLUSION

Women with PULs with progesterone <or= 10 nmol/L at presentation are at low risk of requiring medical intervention and may not benefit from attending routine follow-up visits.