Neonatal Uterine Bleedings: An Ignored Sign but a Possible Cause of Early-Onset Endometriosis - A Systematic Review.

OBJECTIVE: Based on the hypothesis that neonatal uterine bleedings (NUB), occurring mostly in the first week after birth, could represent a pathogenetic mechanism for early-onset endometriosis, this systematic review (SR) was undertaken to evaluate the prevalence and screening strategies used to assess and quantify NUB. DESIGN: Both a SR and a sample literature search in PubMed and Embase were conducted to gather information on NUB prevalence and screening techniques. This was performed by an information specialist. Only full-text articles regarding the assessment of NUB in neonates in the first 2 weeks after birth were included. No limit on language or publication data was used. MATERIALS AND METHODS: The SR was registered in PROSPERO (CRD42019138121). Data was first assessed for eligibility on title and abstract by 2 blinded review authors. Any disagreements were discussed with a third reviewer if necessary. Subsequently, full-text articles were read and assessed for quality using the Cochrane Collaboration Handbook. RESULTS: Out of 1,988 articles in the systematic search, 10 relevant articles were selected, of which 8 were identified through the systematic search and 2 were found through other sources. The sample search of 4,445 articles did not bring up relevant articles. Results were not comparable due to the heterogeneity of screening techniques, although data showed consensus. The prevalence of visible bleeding ranged from 3.3 to 53.8% and the prevalence of occult bleeding from 25.4 to 96.7%. The occurrence was the highest between the 3rd and 7th day postpartum (PP) and the bleeding lasted for 3-4 days on average. Various screening techniques for detecting NUB were found in the literature, including the use of hemoglobin detection devices (such as Hemastix) in the vaginal vestibulum, comparison of diapers with stains of known volume, colposcopy, and ultrasonography. CONCLUSION: The reported prevalence of NUB varies considerably, with a consistent occurrence between the 3rd and the 7th day PP. Literature to assess NUB is dated. The techniques are poorly described and heterogeneous. Future research should focus on prospective cohort studies in order to attempt to correlate NUB cases to (early-onset) endometriosis.

The development of the human uterus: morphogenesis to menarche.

There is emerging evidence that early uterine development in humans is an important determinant of conditions such as ontogenetic progesterone resistance, menstrual preconditioning, defective deep placentation and pre-eclampsia in young adolescents. A key observation is the relative infrequency of neonatal uterine bleeding and hormone withdrawal at birth. The origin of the uterus from the fusion of the two paramesonephric, or Müllerian, ducts was described almost 200 years ago. The uterus forms around the 10th week of foetal life. The uterine corpus and the cervix react differently to the circulating steroid hormones during pregnancy. Adult uterine proportions are not attained until after puberty. It is unclear if the endometrial microbiome and immune response-which are areas of growing interest in the adult-play a role in the early stages of uterine development. The aim is to review the phases of uterine development up until the onset of puberty in order to trace the origin of abnormal development and to assess current knowledge for features that may be linked to conditions encountered later in life. The narrative review incorporates literature searches of Medline, PubMed and Scopus using the broad terms individually and then in combination: uterus, development, anatomy, microscopy, embryology, foetus, (pre)-puberty, menarche, microbiome and immune cells. Identified articles were assessed manually for relevance, any linked articles and historical textbooks. We included some animal studies of molecular mechanisms. There are competing theories about the contributions of the Müllerian and Wolffian ducts to the developing uterus. Endometrium features are suggestive of an oestrogen effect at 16-20 weeks gestation. The discrepancy in the reported expression of oestrogen receptor is likely to be related to the higher sensitivity of more recent techniques. Primitive endometrial glands appear around 20 weeks. Features of progestogen action are expressed late in the third trimester. Interestingly, progesterone receptor expression is higher at mid-gestation than at birth when features of endometrial maturation are rare. Neonatal uterine bleeding occurs in around 5% of neonates. Myometrial differentiation progresses from the mesenchyme surrounding the endometrium at the level of the cervix. During infancy, the uterus and endometrium remain inactive. The beginning of uterine growth precedes the onset of puberty and continues for several years after menarche. Uterine anomalies may result from fusion defects or atresia of one or both Müllerian ducts. Organogenetic differentiation of Müllerian epithelium to form the endometrial and endocervical epithelium may be independent of circulating steroids. A number of genes have been identified that are involved in endometrial and myometrial differentiation although gene mutations have not been demonstrated to be common in cases of uterine malformation. The role, if any, of the microbiome in relation to uterine development remains speculative. Modern molecular techniques applied to rodent models have enhanced our understanding of uterine molecular mechanisms and their interactions. However, little is known about functional correlates or features with relevance to adult onset of uterine disease in humans. Prepubertal growth and development lends itself to non-invasive diagnostics such as ultrasound and MRI. Increased awareness of the occurrence of neonatal uterine bleeding and of the potential impact on adult onset disease may stimulate renewed research in this area.

Effects of progestin-only contraceptives on the endometrium.

INTRODUCTION: The contraceptive activity of synthetic progestins is mediated through three basic mechanisms: (a) An anti-gonadotrophic action leading to the inhibition of ovulation; (b) Changes in cervical mucus characteristics that inhibit sperm penetration and (c) desynchronization of the endometrial picture necessary for implantation. AREAS COVERED: Mechanisms involved in the progestin-induced endometrium desynchronization are individually reviewed for each of the routes of administration and, whenever possible, by individual members of the various families of synthetic progestin derivatives. EXPERT OPINION: For contraceptive purposes, progestins are today administered through several routes: orally, as injections, subdermally and via the vagina or the uterine cavity. Given this variety of modalities, their effects may differ, depending on the route of administration, concentration reached at the level of the endometrium and the duration of use. These are characterized by inactivation of the endometrium. Progestin-only contraception provides a safe and effective control of fertility regulation, although, they are associated with the problem of endometrial break through bleeding that may lead to discontinuation. Unfortunately, in spite of a major research effort over two decades, there is not, as yet, an established long-term intervention available to manage bleeding irregularities, making mandatory a deeper understanding of the mechanisms involved is required.

Acute atherosis and diffuse lipid infiltration of the placental bed: A review of historical lipid studies.

Based on a variety of tissue samples, including Caesarean hysterectomy specimens with the placenta in situ, a detailed map of uteroplacental vascular lesions was established in over a century of research. One such lesion is acute atherosis of unremodelled basal and uteroplacental arteries, defined by the presence of fibrinoid necrosis, subendothelial macrophage foam cells, and perivascular lymphocytic infiltration. Two studies conducted over 50 years ago used Oil Red O staining of frozen tissue sections to visualise lipid infiltration of placental bed vessels and document the presence of lipid-laden foam cells in acute atherosis. These studies also demonstrated that significant amounts of intracellular and extracellular lipids can accumulate in the decidua basalis, often extending into the superficial layer of the myometrium. This phenomenon, termed diffuse lipid infiltration (DLI), was found not only to be prevalent in hypertensive and preeclamptic pregnancies but also associated with postterm pregnancies. Despite being a potential pathognomonic sign of placental malfunction, DLI has been neglected in the context placental bed pathophysiology. To renew interest in this putative pathological feature, and stimulate mechanistic investigations, we review here the original and, to our knowledge, only lipid studies on frozen placental bed tissue sections.

Exploring the challenges for a new classification of adenomyosis.

The availability of non-invasive diagnostic tests is an important factor in the renewed interest in adenomyosis, as the disease can now be more accurately mapped in the uterus without a need for hysterectomy. An agreed system for classifying and reporting the condition will enhance our understanding of the disease and is envisaged to enable comparison of research studies and treatment outcomes. In this review, we assess previous and more recent attempts at producing a taxonomy, especially in view of the latest proposal for subdivision of adenomyosis into an internal and an external variant. In this context, we also explore the uncertainties linked to classifying involvement of the uterovesical pouch, the pouch of Douglas and lesions in the outer myometrium. Two opposing hypotheses are forwarded to explain the pathogenesis of these variants, namely that disease localized in these areas originates from an invasion by uterine adenomyosis of peritoneal organs; alternatively, that lesions present in the outer myometrium originate from peritoneal endometriosis. At the root of debates around these opposing theories of pathogenesis is fragmentary evidence. Because of the limitations of currently available evidence, and until this issue is resolved, broad agreement on a hypothesis to underpin any proposed classification is unlikely.

Pharmacodynamics of combined estrogen-progestin oral contraceptives: 4. Effects on uterine and cervical epithelia.

Introduction: Steroid hormones are responsible for specific changes in the endometrium during the menstrual cycle, when they are sequentially secreted and, because of this, in the early days sequential combined oral contraceptive regimens were utilized. The same basic concept has been utilized with multi-phasic regimens, in order to produce endometrial pictures mimicking the normal cycle.Areas covered: The Endometrial effects of progestins and estrogens; combined monophasic high- (50 µg), medium- (30 µg), low- (20 µg), ultralow- (15 µg) estrogen content; sequential regimens; multiphasic combinations; treatment schedules.Cervical effects of combined high-dose and sequential combinations, including evidence for an increase in malignant lesions.Expert opinion: Overall, combined oral contraceptives (COCs) inhibit normal proliferative changes and the endometrium becomes thin, narrow, with widely spaced glands and pre-decidual changes in the stroma. During the first few cycles the progestin induces a coexistence of proliferative and secretory features; with time, the picture changes because the progestin induces a down-regulation of estrogen receptors, resulting in tortuous glands similar to those in the secretory phase, but characterized by a quiescent, atrophic glandular epithelium.In the cervical epithelium, under the influence of high-dose COCs, endocervical glands became hypersecretory and in some instances, distinctive type of atypical polypoid endocervical hyperplasia is found.

Placental bed research: II. Functional and immunological investigations of the placental bed.

Research on the placenta as the interface between the mother and the fetus has been undertaken for some 150 years, and in 2 subsequent reviews, we attempted to summarize the situation. In the first part, we described the discovery of unique physiological modifications of the uteroplacental spiral arteries, enabling them to cope with a major increase in blood flow necessary to ensure proper growth of the fetus. These consist of an invasion of the arterial walls by trophoblast and a progressive disappearance of its normal structure. Researchers then turned to the pathophysiology of the placental bed and in particular to its maternal vascular tree. This yielded vital information for a better understanding of the so-called great obstetrical syndromes (preeclampsia, fetal growth restriction, premature labor and delivery, placenta accreta). Systematic morphological investigations of the uteroplacental vasculature showed that preeclampsia is associated with decreased or failed transformation of spiral arteries and the persistence of endothelial and smooth muscle cells in segments of their myometrial portion. Here we report on recent functional investigations of the placental bed, including in situ biophysical studies of uteroplacental blood flow and vascular resistance, and manipulation of uteroplacental perfusion. These new methodologies have provided a novel way of identifying pregnancies in which remodeling is impaired. In animals it is now possible to manipulate uteroplacental blood flow, leading to an enhancement of fetal growth; this opens the way to trials in abnormal human pregnancies. In this second part, we explored a new, extremely important area of research that deals with the role of specific subsets of leukocytes and macrophages in the placental bed. The human first-trimester decidua is rich in leukocytes called uterine natural killer cells. Both macrophages and uterine natural killer cells increase in number from the secretory endometrium to early pregnancy and play a critical role in mediating the process of spiral artery transformation by inducing initial structural changes. It seems therefore that vascular remodeling of spiral arteries is initiated independently of trophoblast invasion. Dysregulation of the immune system may lead to reproductive failure or pregnancy complications, and in this respect, recent studies have advanced our understanding of the mechanisms regulating immunological tolerance during pregnancy, with several mechanisms being proposed for the development of tolerance to the semiallogeneic fetus. In particular, these include several strategies by which the trophoblast avoids maternal recognition. Finally, an important new dimension is being explored: the likelihood that pregnancy syndromes and impaired uteroplacental vascular remodeling may be linked to future maternal and even the child's cardiovascular disease risk. The functional evidence underlying these observations will be discussed.

Placental bed research: I. The placental bed: from spiral arteries remodeling to the great obstetrical syndromes.

The term placental bed was coined to describe the maternal-fetal interface (ie, the area in which the placenta attaches itself to the uterus). Appropriate vascularization of this area is of vital importance for the development of the fetus; this is why systematic investigations of this area have now been carried out. Initially, the challenge was the identification and classification of the various successive branching of uterine arteries in this area. These vessels have a unique importance because failure of their physiological transformation is considered to be the anatomical basis for reduced perfusion to the intervillous space in women with preeclampsia, fetal growth restriction, preterm labor, preterm premature rupture of membranes, abruptio placentae, and fetal death. To investigate in depth the pathophysiology of the placental bed, some 60 years ago, a large number of placental bed biopsies, as well as of cesarean hysterectomy specimens with placenta in situ, from both early and late normotensive and hypertensive pregnancies, were carefully dissected and analyzed. Thanks to the presence of a series of specific physiological changes, characterized by the invasion and substitution of the arterial intima by trophoblast, this material allowed the identification in the placental bed of normal pregnancies of the main vessels, the uteroplacental arteries. It was then discovered that preeclampsia is associated with defective or absent transformation of the myometrial segment of the uteroplacental arteries. In addition, in severe hypertensive disease, atherosclerotic lesions were also found in the defective myometrial segment. Finally, in the basal decidua, a unique vascular lesion, coined acute atherosis, was also identified This disorder of deep placentation, coined defective deep placentation, has been associated with the great obstetrical syndromes, grouping together preeclampsia, intrauterine growth restriction, preterm labor, preterm premature rupture of membranes, late spontaneous abortion, and abruptio placentae. More recently, simplified techniques of tissue sampling have been also introduced: decidual suction allows to obtain a large number of decidual arteries, although their origin in the placental bed cannot be determined. Biopsies parallel to the surface of the basal plate have been more interesting, making possible to identify the vessels' region (central, paracentral, or peripheral) of origin in the placental bed and providing decidual material for immunohistochemical studies. Finally, histochemical and electron microscopy investigations have now clarified the pathology and pathogenetic mechanisms underlying the impairment of the physiological vascular changes.

Contraception in autoimmune diseases.

Autoimmune diseases (AIDs) affect women and men with a 2:1 ratio, which suggests that hormonal contraceptives play a role in their clinical course. Combined oral contraceptives have complex, sometimes contradictory, effects on AIDs; they can worsen the situation in women with systemic lupus erythematosus and with anti-phospholipid syndrome, conditions in which they are contraindicated. Early studies indicated a positive effect on rheumatoid arthritis (RA), whereas more recent trials failed to do so, possibly because of the lowering of oestrogen content. Evidence of effects on multiple sclerosis (MS) is conflicting: risk may vary depending on the progestin used. Minor adverse effects may exist on inflammatory bowel diseases, and no significant effect was found on autoimmune thyroid diseases. Women can become sensitised to sex hormones. Progestin-only contraceptives may be used, although copper-releasing intra-uterine devices represent the best option. Finally, several organisations have issued guidelines for contraceptive use in women with AIDs.

Autoimmune diseases: Role of steroid hormones.

Autoimmune diseases (AIDs) are a heterogeneous group of disorders in terms of clinical manifestations, pathogenesis, and prevalence, and there is no agreement to date on a common classification. Adaptive immune responses are responsible for the existence of AIDs, although innate immunity is also involved in misguiding the immune response against self-antigens. Hormones, in general, and in particular steroid hormones, play a critical role in the physiology and pathology of the immune system, especially in adaptive immunity. Hormonal factors, alone or in relation to age, sex, and reproductive status, are involved in conditioning the onset of a number of AIDs. There is a well-defined sexual dimorphism for human AIDs. At the same time, the classic view has been that steroid hormones have well-defined effects, with one type, estrogens, being "pro-inflammatory" and the other two progestogens (progesterone and its synthetic analogs) and androgens being "anti-inflammatory." Although this view has been considered too simplistic and seems contradicted by numerous observations, it remains valid: progestogens and androgens are immunosuppressive and therefore protective against AIDs, whereas estrogens are immune-stimulatory and therefore pathogenic in AIDs.

Uncommon Mixed Endometrial-Myometrial Benign Tumors of the Reproductive Tract: Literature Review.

BACKGROUND: We reviewed published cases of uterus-like mass (U-LM), endomyometriosis, polypoid adenomyoma (PA), adenomyomatous polyp, atypical PA (APA), and adenomyoma. SEARCH METHODS: PubMed, Medline, and Scopus searches of all cases published in the databases till November 26, 2018. RESULTS: We identified 45 case reports of U-LM in the pelvis, 10 cases of endomyometriosis, 44 cases of adenomyomatous polyp, 466 cases of APA and case series of adenomyoma and PA. Most case reports focused on histological description of removed lesions with no or very limited clinical correlates. Histological descriptions were often used interchangeably, which creates considerable confusion. It is unclear if endomyometriosis warrants inclusions as a distinct entity, since the distinction is blurred between adenomyomatous polyp and PA. The glandular epithelium in atypical polypoid adenomyoma exhibits atypia and the lesions have a tendency to recur with a risk of malignant transformation. Smooth muscle metaplasia and Müllerian fusion defects have been proposed as etiology, but it is possible that the lesions do not share a common origin. CONCLUSION: There is need for more detailed and structured description of reported cases including clinical presentation and associated pathology.

Uterine fibroids: an update on current and emerging medical treatment options.

Uterine fibroids are the most common gynecological disorder, classically requiring surgery when symptomatic. Although attempts at finding a nonsurgical cure date back to centuries, it is only around the middle of the last century that serious attempts at a medical treatment were carried out. Initially, both progestins and estrogen-progestin combinations have been utilized, although proof of their usefulness is lacking. A major step forward was achieved when peptide analogs of the GnRH were introduced, first those with superagonist properties and subsequently those acting as antagonists. Initially, the latter produced side effects preventing their routine utilization; eventually, this problem was overcome following the synthesis of cetrorelix. Because both types of analogs produce hypoestrogenism, their use is limited to a maximum of 6 months and, for this reason, today they are utilized as an adjuvant treatment before surgery with overall good results. Over the last decade, new, nonpeptidic, orally active GnRH-receptor blockers have also been synthesized. One of them, Elagolix, is in the early stages of testing in women with fibroids. Another fundamental development has been the utilization of the so-called selective progesterone receptor modulators, sometimes referred to as "antiprogestins". The first such compound to be applied to the long-term treatment of fibroids was Mifepristone; today, this compound is mostly used outside of Western Countries, where the substance of choice is Ulipristal acetate. Large clinical trials have proven the effectiveness of Ulipristal in the long-term medical therapy of fibroids, although some caution must be exercised because of the rare occurrence of liver complications. All selective progesterone receptor modulators produce unique endometrial changes that are today considered benign, reversible, and without negative consequences. In conclusion, long-term medical treatment of fibroids seems possible today, especially in premenopausal women.

Preeclampsia: the role of persistent endothelial cells in uteroplacental arteries.

We explore the potential role of the endothelial lining of uteroplacental arteries in the pathogenesis of preeclampsia, a severe pregnancy disorder characterized by incomplete invasion of the uterine vasculature by extravillous trophoblast and angiogenic imbalance. In normal pregnancy, the endothelium disappears progressively from the uteroplacental arteries and is replaced by trophoblast and deposition of fibrofibrinoid structure, underpinning the so-called physiological transformation of uterine spiral arteries. We hypothesize that partial persistence of the endothelium, albeit injured, initiates a chain of events leading to the emergence of preeclampsia in 3 sequential stages. The first stage results in retention of the endothelium in uteroplacental arteries secondary to incomplete physiological transformation of the vessels. Consequently, the uteroplacental vessels are reactive to pathological cues, which drives local arteriopathy. The second stage starts with progressive reduction in uteroplacental blood flow, generating oxidative stress in the whole placenta, and heightened maternal inflammation in response to circulating trophoblastic debris. In the third stage, generalized endotheliosis causes systemic angiogenic imbalance, hypertension, and other clinical manifestation of preeclampsia.

The placental bed vascular pathology revisited: a risk indicator for cardiovascular disease.

AIM: The present paper intends in the first place to clarify the confusing terminology for describing the vascular pathology of the placental bed in relation to long-term risk of cardiovascular disease. METHODS: Systematic review of relevant topics. RESULTS: The maternal blood supply to the placenta is achieved by some 100 utero-placental spiral arteries with an outside diameter varying between 200 and 600 microns. Defective physiological changes of the myometrial segment of utero-placental spiral arteries and, particularly in preeclampsia associated to hypertensive disease, the presence of atherosclerosis in their proximal segment are a cause of obstructive vascular pathology. On the other hand, basal arteries which supply the inner myometrium and basal decidua are not affected by physiological change and maintain their musculoelastic structure. They can be identified by their external diameter of less than 120 microns. Acute atherosis is an aspecific vascular lesion that occurs in basal as well as spiral arteries inside, as well as outside, the placental bed in association with a variety of obstetrical conditions. CONCLUSIONS: An increased risk of future cardiovascular disease, should be linked to atherosis or, at a later stage, atherosclerosis of utero-placental spiral arteries, rather than to that of decidual basal arteries.

Adolescent Preeclampsia: Pathological Drivers and Clinical Prevention.

Preeclampsia is an important cause of maternal and perinatal morbidity, especially in first-time pregnant adolescent women. Although prevention of preeclampsia has been attempted for many decades, effective intervention can only be achieved upon the full elucidation of the risk factors and mechanisms of disease. As the pathogenesis of preeclampsia during adolescence may differ from that in older women, preventive interventions should be tailored accordingly. During adolescence, 4 putative drivers of preeclampsia can be identified. First, uterine immaturity in very young teenagers is likely a major cause of defective deep placentation and adverse reproductive outcome, underscoring the importance of educational programs and public health initiatives focused on teen pregnancy prevention. Second, the association between adolescent obesity and preeclampsia merits further studies on the benefits of weight loss and dietary interventions to improve pregnancy outcome. Third, there is a need for greater awareness of the link between cardiovascular risk factors in young women and early-onset preeclampsia associated with atherosclerosis of the uteroplacental arteries. Finally, infrequent menstruations may prolong uterine immaturity because of lack of "menstrual preconditioning." This risk factor may be amenable to pharmacological/hormonal preconditioning prior to conception.

Pharmacodynamics of combined estrogen-progestin oral contraceptives 3. Inhibition of ovulation.

INTRODUCTION: Following a historical overview, the ovulation-inhibiting effect of various orally administered estrogen-progestin combinations (combined oral contraceptives [COCs]) are examined for their components alone or in the various combined formulations. Special emphasis is given to products containing natural estrogens. Areas covered: Inhibition of ovulation with progestins alone; estrogens alone; various progestins in combination with ethinyl estradiol; various progestins in combination with natural estrogens (estradiol, estradiol valerate, and estetrol). Expert commentary: The original idea to achieve ovulation blockage through the administration of steroid hormones involved the use a progestogen (both progesterone and its synthetic homologous). The ability of a progestin to inhibit ovulation depends on the type of compound and on its dosage and a difference of more than 20-fold in activity exists between compounds utilized today in COCs. Initially, the estrogenic component was present only because it contaminated the first progestin utilized. It was soon found that an estrogen is necessary for proper cycle control. It was also found that the estrogen acts synergistically in inhibiting ovulation. For almost half a century, most COCs contained ethinyl estradiol. Today, also natural estrogens are being employed. Inhibition of ovulation was complete with all early high dose preparations. Decreasing dosage allowed some ovarian activity to occur, occasionally leading to a mature follicle. Even in this situation, defective corpus luteum formation assured contraceptive protection.

Adenomyosis and Endometrial Cancer: Literature Review.

To confirm the origin of cancer found in both the endometrium and the myometrium is difficult. Cancer may spread from the endometrium into adenomyotic foci or vice versa. Also, premalignant changes may arise at either or both sites. Investigating disease origin enhances our understanding of pathophysiology and prognosis. Additional critical questions are whether women with adenomyosis have a higher risk of endometrial cancer; whether the invasive properties and prognosis of cancer in adenomyosis differ from those arising in the eutopic endometrium and whether the ectopic glandular tissue in adenomyosis becomes altered in the presence of eutopic endometrial cancer. A final question is whether cancer arising within adenomyosis carries a worse prognosis because of its location within the myometrium and the possibility that the presence of adenomyosis facilitates invasion of cancer arising in the eutopic endometrium. The present review explores currently available literature in an attempt to answer these questions and to examine clinical presentations, diagnostic criteria, pathogenesis and prognosis.