Pregnancy-associated plasma protein-A (PAPP-A) is approved to be not pregnancy specific; it could be localized in nonpregnant women endometrium. Thus, it was of interest to see if PAPP-A can be capable of preparing the uterine endometrium for implantation. However, the relationship between serum PAPP-A and endometrium receptivity remains unclear. To evaluate if there is any correlation between the level of serum pregnancy associated plasma protein-A (PAPP-A) with the endometrial thickness and resistance index and evaluate their effects of pregnancy outcome for patient's candidate for intracytoplasmic sperm injection (ICSI). This is a prospective study that was submitted at the infertility center of High Institute for Infertility Diagnosis and Assisted Reproductive Technologies, Al-Nahrain University, Baghdad, Iraq, from November 2020 till March 2021. Forty-five infertile females participated in the study, younger than 40 years old submitted to antagonist protocol. For assessment of endometrium receptivity, transvaginal ultrasound was done at days of oocyte pickup and embryo transfer to measure the endometrial thickness and the resistance index. Serum PAPP-A was measured at the day of oocyte pickup and at day of embryo transfer. Two weeks later, a pregnancy test was done for all patients and according to the result the patients divided into two groups pregnant (n=20) and non-pregnant (n=25). There was insignificant positive correlation between serum PAPP-A level with endometrial thickness (ET) and insignificant negative correlation with (RI) at day of oocyte pick up and day embryo transfer. High serum Pregnancy associated plasma protein-A (PAPP-A) may be associated with an increase in endometrial thickness and low level of resistance index that both may promote the possibility of implantation.