Jan J. Brosens

Implantation requires coordinated interactions between the conceptus and surrounding decidual cells, but the involvement of clock genes in this process is incompletely understood. Circadian oscillations are predicated on transcriptional-tra…

BACKGROUND: Scientific data on the phenomenon of uterine bleeding in the neonate (NUB) began to appear over a century ago when angiogenesis and petechial haemorrhages in the endometrium of newborn female infants, as well as fluid blood with…

The pathogenesis of early-onset endometriosis has recently been revisited, sparked by the discovery of endometrial stem/progenitor cells and their possible role in endometriosis, and because maternal pregnancy hormone withdrawal following d…

The pathogenesis of endometriosis remains poorly understood at least in part because early stages of the disease process are difficult to investigate. Previous studies have proposed a three-dimensional fibrin matrix culture model to study h…

BACKGROUND: Decidualizing human endometrial stromal cells (HESCs) profoundly up-regulate 11β-hydroxysteroid dehydrogenase type 1 (11βHSD1), the enzyme that converts inert cortisone to active cortisol. We postulated that the induction of a c…

Study question: To compare the pregnancy rate in patients submitted to FET (Frozen Embryos Transfer) of cleavage stage embryos (Group 1), or at the blastocyst stage (Group 2). Summary answer: Our data showed that the transfer of frozen blas…

BACKGROUND Mechanisms underlying early reproductive loss in the human are beginning to be elucidated. The migratory and invasive capacity of human endometrial stromal cells (ESCs) is increasingly recognized to contribute to the intense tiss…

AIM: The rate of oocyte decline follows a biphasic pattern, characterized by acceleration between 32 and 38 years old. Ovarian reserve is also affected by external factors, including ovarian disease and iatrogenic damage. The aim of this st…

Bleeding from endometriotic implants is now an established cause of acute hemoperitoneum in pregnancy. However, the adverse impact of pelvic endometriosis on uterine function before conception may also interfere with subsequent deep placent…

The eutopic endometrium in women suffering from endometriosis is different in many ways from that of healthy controls. Both proliferative and secretory eutopic endometria exhibit changes in endometriosis with heterogeneous responses. In add…

All fundamental reproductive events in the human ovary and uterus, including ovulation, implantation and menstruation, are dependent upon profound tissue remodelling, characterized by cyclical waves of cell proliferation, differentiation, r…

Throughout the reproductive years, the rise and fall in ovarian hormones elicit in the endometrium waves of cell proliferation, differentiation, recruitment of inflammatory cells, apoptosis, tissue breakdown and regeneration. The activated …

Differentiation of human endometrial stromal cells into specialized decidual cells is critical for embryo implantation and survival of the conceptus. Initiation of this differentiation process is strictly dependent on elevated cAMP levels, …

Key reproductive events, including ovulation, implantation and menstruation, are dependent upon cyclic tissue remodeling, characterized by waves of cell proliferation, differentiation, recruitment of inflammatory cells, apoptosis, tissue br…

The rise and fall in ovarian oestrogen and progesterone production orchestrates a series of events that are indispensable for reproduction, including ovulation, implantation, decidualisation and menstruation. In the uterus, these events inv…

Endometrial cancer is the most common malignancy of the lower female reproductive tract. The tumor suppressor FOXO1 is downregulated in endometrial cancer compared with normal endometrium but the underlying mechanisms are not well understoo…

Local estrogen production plays a key role in proliferative endometrial disorders, such as endometrial hyperplasia and cancer. Hydroxysteroid (17beta) dehydrogenase 1 (HSD17B1) is an enzyme that catalyzes with high efficiency the conversion…

Menstruation is widely viewed as serving no purpose other than to reinitiate the endometrial cycle in the absence of pregnancy. Yet, it is striking that cyclic endometrial decidualization followed by menstrual shedding is confined to the fe…

Spontaneous hemoperitoneum in pregnancy (SHiP) is a rare but dramatic cause of perinatal mortality and morbidity. Emerging evidence suggests that pelvic endometriosis may play an important role in the pathogenesis of SHiP.

All key reproductive events in the human ovary and uterus, including follicle activation, ovulation, implantation, decidualization, luteolysis and menstruation, are dependent upon profound tissue remodelling, characterised by cyclical waves…

Pregnancy is dependent upon the endometrium acquiring a receptive phenotype that facilitates apposition, adhesion and invasion of a developmentally competent embryo. Surface-enhanced laser desorption/ionization time-of-flight mass spectrome…