The predictive value of urinary Progesterone metabolite PdG testing in pregnancy outcomes

Abstract Background: Progesterone is essential for establishing and maintaining a pregnancy. However, premature atresia of the corpus luteum (CL) or sub-optimal progesterone secretion after ovulation may result in the decreased ability to establish or maintain a pregnancy. The current limitations of serum hormone testing fail to give a complete picture of progesterone production across the luteal phase required for pregnancy.Methods: Pregnanediol-3a-glucuronide (PdG) is a progesterone metabolite that can be detected via non-invasive, self-administered urinary test strips and can be used to monitor progesterone production. PdG test strips were used by 185 women and taken multiple times during the luteal phase. Results were analysed by Fisher’s exact test.Results: Of the 185 enrolled women, 172 had complete cycles. Of the 172 women who demonstrated complete cycles, 54 (31.4%) women reported pregnancies. Thirty-five (64.8%) of these pregnancies resulted from a PdG positive cycle with a miscarriage rate of 14.3% (5/35). Nineteen pregnancies (35.2%) resulted from PdG negative cycles with a miscarriage rate of 89.5% (17/19). The association of a negative or positive cycle with pregnancy outcome was significant (two-sided p=0.0001). Positive PdG cycles are associated with increased pregnancy rates and lower odds of a first-trimester pregnancy loss.Conclusions: A consideration for luteal phase support with progesterone or ovulation induction in women with negative PdG cycles can be of benefit to increase pregnancy rates. Furthermore, the use of LH and PdG testing prior to conception can be used as a screening tool to potentially identify women who are at risk of subfertility and at a higher risk of first-trimester pregnancy loss related to low progesterone.Trial registration: NCT05033366. Registered 02 September 2021, https://clinicaltrials.gov/ct2/show/NCT05033366