The role of midluteal progesterone for the prediction of pregnancy after ovulation induction with clomiphene citrate for unexplained infertility

Abstract

To investigate the role of midluteal progesterone (MLP) for the prediction of pregnancy after ovulation induction with clomiphene citrate (CC) for unexplained infertility. prospective cohort. A total of 271 ovulation induction cycles with CC in 140 patients aged between 18-40 years diagnosed with unexplained infertility were recruited in the study between April and December 2012. The women were given a 5 day course of 50-150 mg of CC starting on day 2 -5 of the menstrual cycle and ovulation was triggered with 10 000 IU of human chorionic gonadotropin (hCG) when the dominant folicule reached 18mms. We performed intrauterine insemination (IUI) 36 hours after the hCG injection. We collected venous blood samples on day 21-23 of the cycle for the measurement of MLP levels. We performed a pregnancy test in women who missed their menstrual periods and clinical pregnancy was documented with detection of cardiac activity on ultrasonographic examination. Statistical analysis was performed by the SPSS package 20.0 version. Paired t test was used to compare baseline and biological characteristics. ROC analysis was performed to determine a cut off value for MLP for the prediction of pregnancy. Clinical pregnancy rate was 10,3 % (28/271). Age and BMI of the patients with a positive pregnancy test and the ones who failed to achieve pregnancy were similar (p=0.81and p=0.15, repectively). Midluteal progesterone levels were significantly elevated in patients who achieved pregnancy than the ones who failed (31,72 ±12,58 ng/ml versus 18,59±8,91ng/ml, p=0.00). A treshold value of 22,5 ng/ml was established for MLP following analyses repeated with balanced distributions. MLP values over 22,5 ng/ml had a positive predictive value of 67,8 % and those below 22,5 ng/ml had a negative predictive value of 81,2% for the prediction of pregnancy. Midluteal progesterone levels may be useful for the prediction of pregnancy in CC cycles in patients with unexplained infertility.