Periodicity in the levels of serum plasminogen activator inhibitor-1 is a robust prognostic factor for embryo implantation and clinical pregnancy in ongoing IVF cycles

CONTEXT: Plasminogen activator inhibitor-1 (PAI-1) has been inversely correlated to proteolytic extracellular-matrix degradation exerted by urokinase-type (u-PA) and tissue-type plasminogen activators (t-PA). Any pathological disturbance in PAI-1 levels may lead to several pregnancy complications. AIMS: To assess the influence of periodicity in serum PAI-1 levels on embryo implantation and clinical pregnancy outcome in IVF cycles SETTINGS AND DESIGN: Prospective study of 120 IVF cycles at private infertility centre. MATERIAL AND METHODS: Endometrial response (ER) assessment by measuring Endometrial thickness (cm) and echopattern (grade). Serum PAI-1(ng/ml) measurement by ELISA method on day of hCG, day of ET and days 7 and 14 of ET. Main outcome measure was clinical pregnancy. STATISTICAL ANALYSIS: Student “t” test, ANOVA, Post-test for linear trend, Pearson Correlation. RESULTS: PAI-1 levels declined from dhCG to dET (318.8 ± 36.1 to 176.1 ± 28.4) whereas they increased steadily from dET to d7 to d14ET (176.1 ± 28.4 to 285.2 ± 30.4 to 353.5 ± 150.4; P = 0.0004) in pregnant group (n = 31). Conversely, dhCG to dET levels increased in both nonpregnant (n = 75; 173.8 ± 18.3 to 280.8 ± 26.1) and biochemical pregnancy BCP (n = 14; 172.7 ± 31.1 to 216 ± 30.1) groups. The rising pattern from dET to d7 to d14ET was not observed in non-pregnant and BCP groups. ER thickness and grade shared significant correlation with serum PAI-1 on dET (Pearson r: ER = 0.28, Grade = 0.29) and d7ET (Pearson r: ER = 0.40, Grade = 0.23). CONCLUSIONS: Periodicity in serum PAI-1 levels offers a robust prognostic factor for predicting clinical pregnancy outcome. The dhCG to dET PAI-1 transition is a decisive factor for either transferring embryos in same/ongoing cycle or cryopreserving them and postponing ET to subsequent natural cycle.