Tuesday, April 13, 2021
Saturday, April 3, 2021
Saturday, March 6, 2021
Cervical insufﬁciency is characterized by asymptomatic dilation of the internal os during pregnancy. This generally leads to dilation of the entire cervical canal during the second trimester with subsequent risk of rupture of the membranes and/or expulsion of the fetus. This affects 1/54 to 1/1842 pregnancies (resulting from uncertain diagnostic criteria). Though uncommon, it is thought to be involved with as many as 20% to 25% of all second-trimester pregnancy losses.
Abortion is the loss or failure of an early pregnancy and it is deﬁned in several forms: complete, incomplete, inevitable, missed, septic, and threatened. A complete abortion is the termination of a pregnancy before the age of viability, typically deﬁned as occurring at less than 20 weeks from the ﬁrst day of the last normal menstrual period or involving a fetus of weight less than 500 g. Most complete abortions generally occur before 6 weeks or after 14 weeks of gestation. An incomplete abortion is the spontaneous passage of some, but not all, of the products of conception. A pregnancy in which rupture of the membranes and/or cervical dilation takes place during the ﬁrst half of pregnancy is labeled an inevitable abortion. Uterine contractions typically follow, ending in spontaneous loss of the pregnancy for most patients. A missed abortion is the retention of a failed intrauterine pregnancy for an extended period. A septic abortion is a variant of an incomplete abortion in which infection of the uterus and its contents has occurred. A threatened abortion is a pregnancy that is at risk for some reason. Most often, this applies to any pregnancy in which vaginal bleeding or uterine cramping takes place but no cervical changes have occurred. Estimates for the frequency of complete abortions are as high as 50% to 60% of all conceptions and between 10% and 20% of known pregnancies. Less than 2% of fetal losses are missed abortions. Septic abortions occur in 0.40 to 0.6 of 100,000 spontaneous pregnancy losses. Threatened abortions occur in 30% to 40% of pregnant women.
ECTOPIC PREGNANCY III— INTERSTITIAL, ABDOMINAL, OVARIAN
When, during the process of abortion or rupture, the trophoblast, after total separation, implants itself again somewhere in the peritoneum, as happens on rare occasions, it may grow and develop into a secondary abdominal pregnancy. The embryo in such cases may have remained in its original amniotic sac, or a new sac may have formed from the surrounding tissues. A secondary abdominal pregnancy may also result from a beginning tubal implantation that ruptured and became inserted between the leaves of the broad ligament. If the latter should rupture again, the embryo in the fetal sac may extrude into the peritoneal cavity, with the placenta remaining in the extraperitoneal position between the broad ligament sheets. In still more exceptional cases, the fertilized ovum may escape through the open end of the tube, attaching itself to the parietal or visceral peritoneum or the omentum, developing into a primary abdominal pregnancy. It has even been reported that an abdominal pregnancy has originated from a defect in the uterine wall, which had been ﬁlled and closed up by the omentum during the healing period after cesarean section. The remarkable feature of these abdominal pregnancies is that they may continue to near term before an occasion for diagnosis may even arise, even in the face of repeated ultrasonographic studies. The incidence of abdominal pregnancy is estimated to be roughly 1 in 10,000 live births.
ECTOPIC PREGNANCY II—RUPTURE, ABORTION
Very rarely does a tubal pregnancy develop longer than into the fourth or ﬁfth month without symptoms and signs that ultimately lead to the diagnosis. The most frequent outcome of tubal pregnancy is abortion through the tube into the peritoneal cavity. It usually occurs between the middle of the second and the end of the third month, but it may come earlier. A partial or total separation of the trophoblast from the tubal walls occurs, leading to death of the embryo. Blood extravasation and later extrusion of the embryo with blood clots into the peritoneal cavity follow, where they may slowly be absorbed, provided the hemorrhage was slight. The uterine decidua may sometimes separate as a whole and be eliminated as a decidual cast of the uterine cavity. Passage of the decidual cast can be confused with an early spontaneous abortion, and hence the passed tissue should be carefully examined.
ECTOPIC PREGNANCY I—TUBAL PREGNANCY
Ectopic pregnancy refers to the implantation of the embryo in any place outside the uterine cavity. According to the site of implantation, four kinds of ectopic pregnancy are distinguished: tubal, ovarian, abdominal or peritoneal, and cervical. Between 10 and 15 of every 1000 pregnancies are ectopic, with the rate varying with age, race, and geographic location (highest in Jamaica and Vietnam).
HORMONAL FLUCTUATIONS IN PREGNANCY
In addition to its function as the agent of transfer of gases and nutrients, the placenta also has signiﬁcant endocrine activity. It produces progesterone, which is important in maintaining the pregnancy; somatomammotropin (also known as placental lactogen), which acts to increase the amount of glucose and lipids in the maternal blood; estrogen; insulin-like growth factors; relaxin; and –human chorionic gonadotrophin (β-hCG). This hormonal activity is the main cause of the increased maternal blood glucose levels seen in pregnancy, which results in an increased transfer of glucose and lipids to the fetus.
Monday, February 15, 2021
SUPPORT OF PELVIC VISCERA
To clarify the relationships of muscles and fasciae in supporting the pelvis, with particular reference to the vagina and internal female genitalia, the uterus, in the accompanying picture, has been elevated upward and backward. The plane chosen for the section (small upper diagram) runs from a point anterior to the body of the uterus down through the anterior vaginal fornix and along the longitudinal axis of the vagina to the perineum. At this level, the large iliac vessels run close to the superior pubic rami which form the lateral pelvic walls. These pubic rami are connected to the ischiopubic rami across the obturator foramen by the obturator membrane, the obturator internus muscle, and the obturator fascia. The broad ligaments begin at the lateral pelvic walls as double reﬂections of the parietal peritoneum, forming large wings, which divide to include the uterus and separate the pelvic cavity into anterior and posterior compartments. They are continuous with the peritoneum of the bladder anteriorly and the rectosigmoid posteriorly. The broad ligaments contain fatty areolar tissue, blood vessels, and nerves, and at their apices invest the round ligaments, which are condensations of smooth muscle and ﬁbrous tissue holding the uterus forward and inserting below and anterior to the fallopian tubes. The left ovary has been lifted up to demonstrate the uteroovarian and infundibulopelvic ligaments, the latter containing the ovarian blood supply. The bladder peritoneal reﬂection has been detached from the uterus, revealing the endopelvic or uterovaginal fascia, which runs laterally to the pelvic wall as the cardinal ligament, and with the associated blood vessels, nerves, and fat forms the parametrium. The uterine arteries and veins extend medially from their origins in the hypogastric vessels to the lateral vaginal fornices. The ureters (cross-sectioned) at this point pass beneath the uterine vessels and then continue in the uterovaginal fascia medially and anteriorly across the upper vagina into the bladder. The close proximity of the ureters to the uterine blood supply and vagina explains why they may easily be injured during hysterectomy and in operations to repair lacerations of the endopelvic fascia.
PELVIC DIAPHRAGM II—FROM ABOVE
The pelvic diaphragm forms a musculotendinous, funnel-shaped partition between the pelvic cavity and the perineum and serves as one of the principal supports of the urethra, vagina, rectum, and pelvic viscera. It is composed of the levator ani and coccygeus muscles, sheathed in a superior and inferior layer of fascia. The muscles of the pelvic diaphragm extend from the lateral pelvic walls downward and medially to fuse with each other and are inserted into the terminal portions of the urethra, vagina, and anus. Anteriorly, they fail to meet in the midline just behind the pubic symphysis, exposing a gap in the pelvic ﬂoor, which is completed by the urogenital diaphragm. This gap is partially ﬁlled by the subpubic ligament that is pierced by the dorsal vein of the clitoris. In this area, the inferior fascia of the pelvic diaphragm fuses with the superior fascia of the urogenital diaphragm.
PELVIC DIAPHRAGM I—FROM BELOW
Removing the superﬁcial muscles and fasciae of the pelvic ﬂoor, the pelvic diaphragm, viewed from below, forms a hammock of muscle from the pelvic brim, investing the urethra, vagina, and rectum and attaching posteriorly to the sacrum and coccyx. The principal muscles of this group are the levatores ani, consisting of both medial and lateral components on each side and supplied by the pudendal nerve. The larger medial component, the pubococcygeus, arises from the posterior surface of the superior ramus of the pubis adjacent to the symphysis, whence the ﬁbers pass downward and backward around the lateral walls of the vagina, with some ﬁbers reaching the coccyx, some terminating in the fascia forming the central tendinous point of the perineum, and others blending with the longitudinal muscle coats of the rectum. The pubococcygei are separated medially by the interlevator cleft through which pass the dorsal vein of the clitoris, the urethra, vagina, and rectum. These organs are supported by musculofascial extensions from the pubococcygei, their inferior fascia being continuous with the superior fascia of the urogenital diaphragm.
The vagina (from Latin, literally “sheath” or “scabbard”) serves as the portal to the internal female reproductive tract and a route of egress for the fetus during delivery. The viscera contained within the female pelvis minor include the pelvic colon, urinary bladder and urethra, uterus, uterine tubes, ovaries, and vagina. These structures surround the vagina and interact with it in the clinical setting. Therefore, the vagina also provides a convenient portal to understanding the female pelvic viscera.
Female circumcision is a culturally determined practice of ritually cutting a female’s external genitals that results in removal of part or all of the external genitalia including the labia majora, labia minora, and/or the clitoris. This activity is illegal in many locations. Female circumcision (female genital mutilation, inﬁbulation) is generally performed as a ritual process, often without beneﬁt of anesthesia and frequently under unsterile conditions, generally near the time of puberty or soon after. The resulting scarring may preclude intromission or normal vaginal delivery should pregnancy be achieved. In rare cases, scarring and deformity may be sufﬁcient to result in amenorrhea or dysmenorrhea. The ritual is often performed to reinforce a woman’s place in her society, to establish eligibility for marriage and entry into womanhood. It is sometimes also performed to safeguard virginity or to paradoxically improve fertility. Although the ritual can have devastating effects on the woman’s sexual pleasure, it is some- times performed to enhance the husband’s pleasure.
Sunday, February 14, 2021
About 5% of the malignant tumors of the female genital organs originate on the vulva. (The incidence of vulvar cancer rose by approximately 20% between 1973 and 2000, likely related to increased exposure to human papillomavirus [HPV].) Primary carcinoma is almost always seen in elderly women with an average age for in situ tumors being 40 to 49 years, and 65 to 70 for invasive lesions. The vast majority of these tumors are of the squamous cell variety. Histologic types include squamous cell (90%), melanoma (5%), basaloid, warty, verrucous, giant cell, spindle cell, acantholytic squamous cell (adenoid squamous), lymphoepithelioma-like, basal cell, and Merkel cell. Sarcoma accounts for approximately 2% of vulvar cancers. Metastatic tumors from other sources are rare but do occur.