Use of hormonal contraception after hydatidiform mole.

Abstract

Effective contraception is important during monitoring of human chorionic gonadotrophin (hCG) levels after uterine evacuation for hydatidiform mole (HM), to avoid confusion between a rising hCG associated with ongoing gestational trophoblastic disease (GTD) and that resulting from a new pregnancy. Contraception should be started as soon as possible: conception can occur before menses are re-established. But how do women achieve effective contraception in the immediate aftermath of molar pregnancy? Typically, condom use is associated with an 18% contraceptive failure rate over a year of use. Intrauterine contraception has been avoided in GTD because of concerns about possible increased risk of bleeding and uterine perforation. Hormonal contraception (HC) is effective: the progestogen-only implant has a typical use failure rate of only 0.05% over a year, oral contraception 9% and injectables 6%. On discontinuation of HC (except injectables), there is a rapid return to fertility – important to many women after an episode of GTD. However, guidelines regarding use of HC during follow up of HM have been inconsistent. Royal College of Obstericians and Gynaecologists guidance (Green Top Guideline 38, London: RCOG; March 2010) recommended that HC be avoided until hCG levels normalised because of concern that use of combined HC after molar pregnancy might increase the risk of gestational trophoblastic neoplasia. However, a systematic review by Gaffield et al. (Contraception 2009;80:363–71) found no evidence of an effect of combined HC on the course of GTD after HM. On this basis, the 2009 World Health Organization Medical Eligibility Criteria for Contraceptive Use recommended that there should be no restriction on use of HC while hCG levels are elevated in GTD. In line with this, the Faculty of Sexual and Reproductive Healthcare (UK Medical Eligibility Criteria for Contraceptive Use, London: FSRH; 2009) and Centers for Disease Control (US Medical Eligibility Criteria for Contraceptive Use, Atlanta: CDC; 2010) advise that HC can safely be used while hCG remains elevated. In the current retrospective database study, Braga et al. find no association between use of HC started while hCG levels are still raised after uterine evacuation for complete HM and time to hCG regression, development of gestational trophoblastic neoplasia or FIGO risk score. The study includes 2423 women with complete HM. However, only 154 used HC (100 combined oral contraception, 43 progestogen-only pill, 11 progestogen-only injectable). Because numbers of women using each contraceptive were small, methods are considered together as ‘hormonal contraception’. The study is not powered to detect different effects of individual HC methods on GTD outcomes. Progestogen-only implants and non-oral combined contraceptives are not considered. Contraceptive method was not randomised. Prescribing might have been influenced by plateaued or rising hCG levels or by bleeding problems in the weeks following uterine evacuation so there is a potential prescribing bias. Despite its limitations, this study adds to the weight of evidence that suggests HC can safely be used after molar pregnancy before hCG levels normalise. Clinicians caring for women with a diagnosis of molar pregnancy should not forget about contraception and can advise women that the limited evidence is that HC is safe to start. None declared. Completed disclosure of interests form available to view online as supporting information. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.