Human implantation is a highly complex and multifactorial process. Successful implantation requires the presence of a healthy embryo, a receptive endometrium, and a synchronized molecular dialogue between the two, as well as immune tolerance/protection from the host. The endometrial receptivity refers to a hormonally limited period in which the endometrial tissue acquires a transient functional status allowing blastocyst implantation and pregnancy initiation. Global knowledge of endometrial receptivity grew up in recent years. Improvements in genetics, new biomarkers, noninvasive methods, new advanced techniques (Endometrial receptivity assay – the ERA system, proteomic analysis) offer the possibility to evaluate the endometrial status and to manage patients with infertility problems, especially women undergoing assisted reproductive treatment. This overview reports the most relevant knowledge and recent advances in the study of implantation processes from the perspective of the endometrium, often considered as being the main barrier for a successful pregnancy initiation. Endometrial receptivity is a topic of great interest and further studies are needed for the early identification of endometrial abnormalities and the discovery of new strategies for increasing the chance for the establishment of pregnancy.

The aim of our study was to investigate the interrelations of symptoms, clinical outcomes and treatment regimens in pregnant women, diagnosed with myasthenia gravis and superimposed COVID-19 infect...

Various factors related to an “in vitro” fertilization (IVF) procedure may influence the rate of small for gestational age (SGA) newborns in such pregnancies.The aim of the study was to determine n...

Dear Editor,The aim of this letter is to alert for a possible link between COVID-19 infection during pregnancy and subsequent secondary atrophy/atresia of one of the umbilical arteries (UAs). We co...

Objectives: To analyze the recurrence rate of placenta-mediated diseases (PMDs) such as preeclampsia (PE) and/or intrauterine growth restriction (IUGR), intrauterine fetal death (IUFD), and placental abruption (PA) in high-risk patients on antithrombotic therapy (AT) because of a previous obstetrical history for such complications. Methods: The study group (SG) included 150 patients to whom either 100 mg of aspirin or low-molecular weight heparin (LMWH) was administered due to a previous history of PMDs. The AT in the SG was started before 16 gestational weeks (g.w.). The patients in the first control group (CG-1) were 150 who also had a previous obstetrical history of PMDs, but did not receive antithrombotic therapy (AT) throughout their ongoing pregnancies. The second CG (CG-2) comprised 320 patients with a previous history of normally developing pregnancies and without AT throughout their ongoing pregnancies. Results: The total percentage of PE in pregnant patients from the SG was 25.3% (38/150 patients), with 22.2% (10/45) in the SG on AT only with LDA (SG-LDA group), 25% (17/68) in the SG on AT only with LMWHs (SG-LMWH group) and 29.7% (11/37) in the SG on combined AT with LDA and LMWHs (SG-LDA + LMWH group), as opposed to 18.67% (28/150) in CG-1 and 0.62% (2/320) in CG-2. The recurrent severe PE/total PE ratio in the SG was 44.7% (17/38), with 30% (3/10) in the SG-LDA group, 47% (8/17) in the SG-LMWH group and 54% (6/11) in the SG-LDA + LMWH group, against 75% (21/28) in CG-1. There were no cases with severe PE in CG-2. All cases with recurrent IUGR from the SG were equal to 13.3% (20/150), with 13.3% (6/45) in the SG-LDA group, 11.76% (8/68) in the SG-LMWH group and 16.2% (6/37) in the SG-LDA + LMWH group, as compared to 30% (45/150) in CG-1 and 5% (16/320) in CG-2. As a whole, the overall recurrence rate of PMDs in the SG was 38.67% (58/150), with 35.56% (16/45) in the SG-LDA group, 36.76% (25/68) in the SG-LMWH group and 45.9% (17/37) in the SG-LDA + LMWH group, as compared to 50.67% (76/150) in CG-1 and 5.94% (19/320) in CG-2. Conclusion: AT had a partial beneficial effect on the prophylaxis of recurrent PMDs. On the one hand, AT led to a significant reduction in the recurrent severe PE/total PE ratio, as well as in the total PMDs’ recurrence rate in the SG as compared to the one in CG-1. On the other hand, the percentage of recurrent PMDs still remained significantly higher in the SG as compared to CG-2. Pregnant patients with previous PMDs still need close surveillance in subsequent pregnancies as they remain at a high risk for complications.

There are not many management options at the time of delivery in patients with placenta accreta spectrum (PAS) disorders. We conducted a small observational study on such cases managed in our tertiary maternal care centre at University Obstetrics and Gynecology Hospital “Maichin Dom” in Sofia, Bulgaria, between January 1, 2019 and December 31, 2023. Caesarean section (CS) hysterectomy still seems inevitable in most cases where other conservative management techniques are strongly considered impractical.