Does maternal serum progesterone level in early pregnancy predict placental dysfunction in third trimester

Objective Progesterone, which is necessary for maintenance of pregnancy, is secreted by corpus luteum until 10 weeks of gestation, and is produced from the placenta afterwards. Aim of this study is to investigate the relationship of serum progesterone concentrations measured in 6–8 weeks and 12 weeks of gestation with the parameters that may demonstrate placental dysfunction in the third trimester. Methods Relationship of the progesterone values measured at 6–8 weeks and 12 weeks of gestation with indicators of placental dysfunction, including hypertensive disorders of pregnancy, intrauterine growth restriction, preterm delivery and low birth weight, were evaluated. Furthermore, based on a previous study, two groups with progesterone levels below and above 11 ng/mL in early pregnancy were formed, and the difference between these groups regarding gestational outcomes were investigated. Results Progesterone concentrations at 6–8 and 12 weeks of gestation were not significantly different between the subgroups with and without gestational complications indicating placental dysfunction (p>0.05 for all parameters). As for the two groups, significant difference was not found in terms of third trimester complications due to progesterone cut-off of 11 ng/mL at 6-8 weeks of gestation. Conclusion In this study, we did not find progesterone values measured at early and late first trimester periods to be associated with placental dysfunction in the third trimester. Also, we did not validate a previously suggested threshold value to predict gestational outcome. Therefore, routine first trimester progesterone screening in guiding pregnancy follow-up may not be appropriate.