Chapter VII - Obstetric Procedures
Alpha-fetoprotein is a globulin produced by liver and other tissues of the fetus and the newborn. Its level normally declines after one year of age. An elevation of alpha-fetoprotein may suggest hepatocellular carcinoma, viral hepatitis, hepatic cirrhosis, and various teratocarcinomas and embryonal carcinomas of gonadal origin. Elevation of alpha-fetoprotein (AFP) occurs in neural tube defects (anencephaly, spina bifida).
Amnion is the innermost membrane enveloping the embryo. Sometimes, to test the fetal abnormalities, a hollow needle is inserted into the uterus of a pregnant woman and tissue samples are drawn out. This puncture of amniotic sac and removal of amniotic fluid is known as amniocentesis. The tissue samples are cultured for biochemical and cytological studies.
Chorionic villus sampling
Chorionic villus sampling or CVS is used to detect chromosomal abnormalities and biochemical disorders of the fetus. A catheter is inserted into the cervix and in the outer portion of the cervix, and a sample of chorionic villi is obtained.
Colposcope is a stationary low-power microscope used in conjunction with a vaginal speculum to inspect the cervix. Colposcopy facilitates the identification of cervical dysplasia in women with abnormal Pap smears and as an aid in biopsy and excision procedures.
C-section is carried out in cases of cephalopelvic disproportion, presence of STDs, fetal distress, and breech presentation. The abdomen and the uterus are incised (abdominal hysterotomy) to remove the fetus.
An endoscopic inspection of the cul-de-sac or the pouch of Douglas is known as culdoscopy. Cul-de-sac is the lowermost part of the peritoneal cavity and lies between the uterus and the rectum. Culdoscopy is performed under anesthesia, and the instrument, culdoscope, is inserted vaginally.
Dilatation and Curettage
The cervical canal is widened with a graded dilator, and the uterine endometrium is scraped with a curette. This procedure is resorted to in cases of cytologic examination, abnormal uterine bleeding, and as a therapeutic measure for incomplete abortion. This procedure is generally done in the operating room under anesthesia.
Endometrial smear/endometrial biopsy
Endometrial smear or endometrial biopsy refers to the microbiologic study of tissue samples from the endometrium. This histological study detects any abnormality or malignancy in the high-risk patients. Endometrial smear is performed during a gynecologic examination. This procedure is performed under local anesthesia and a thin, hollow curette is used to extract the endometrial tissue, which is then sent for laboratory studies.
Exfoliative cytology is the microscopic examination of the stained cells, which are usually brushed or scraped from the uterine cervix or the interior of the stomach. This cytology detects any malignant or premalignant changes.
Laparoscopy implies inspection of the abdominal cavity. An incision is made through the abdominal wall and an endoscope is inserted. This endoscope, which is a tubular instrument with illumination and magnification facility, is inserted though the incision, and the pelvic viscera are explored for any abnormality.
Papanicolaou test or Pap test
In this test, superficial cells are removed from the vagina and cervix for a cytologic examination. Hormonal effects are determined and abnormal cell changes detected. The reasons are generally traced to inflammation, infection, dysplasia, and sometimes actual malignancy. The samples of the exfoliative cells are taken from the following areas: the vaginal vault, the squamocolumnar junction, and the endocervical canal. Squamocolumnar junction refers to the transition line between the squamous epithelium of the vagina and the columnar epithelium of the endocervical canal. The specimens from the vaginal vault and the squamocolumnar junction are taken with the help of a wooden spatula (Ayre spatula in case of squamocolumnar junction). A bristle brush is used to secure the sampling of the columnar cells from the endocervical canal. The results are explained as per the Bethesda system. The adequacy of the specimen is assessed and effects of estrogen and progesterone are determined. Inflammatory, degenerative, dysplastic, and malignant changes in cells are identified. Other infections, like candida, trichomonas, herpes simplex, are detected.
The detection of chorionic gonadotropin in the serum is the basis for most serum pregnancy tests in current use. The result of this qualitative test may be reported as simply positive or negative. Urine pregnancy test depends on identification of chorionic gonadotropin in urine. Serum hCG levels rise rapidly in early gestation. Human chorionic gonadotropin can be measured by the following tests: bioassay, agglutination immunoassay, radioimmunoassay, radioreceptor assay, and immunometric assay. Immunoassay is one of the most important, rapid, inexpensive, and relatively reliable tests for pregnancy.
Tubal ligation is a contraceptive method (sterilization surgery) in which the continuity of uterine tubes or oviducts is interrupted by cutting, cautery, or by a plastic or metal device to prevent a future conception.
Ultrasonography is a radiographic procedure, during which ultrasonic waves are used to produce an image or photograph of a tissue or organ. Ultrasonic waves are passed through the tissues having different densities and resultant images are recorded. This is a non-invasive technique to evaluate the female reproductive system and the fetus.
Contraceptives (steroidal, chemical)
Contraceptives inhibit ovulation and thereby act as a deterrent against pregnancy. They are available in the form of steroids and chemicals. Steroids are generally oral contraceptive pills (OCPs), a combination drug of estrogen and progesterone. On the other hand, chemical contraceptives come as foam, gel, cream, or other spermicidals, which are placed in the vagina before the intercourse. They prevent pregnancy by killing the sperms. Some of the oral contraceptives used are ethinyl estradiol and levonorgestrel, mestranol and norethindrone.
Estrogen hormones are used as oral contraceptives as well as in the treatment of postmenopausal osteoporosis. They act by binding the estrogen nuclear receptors. However, prolonged use of this hormone can lead to skin rash, thromboembolism, and endometrial cancer. Estradiol (Estrace), estrogens and medroxyprogesterone (Prempro) are some examples.
Oxytocin is a neurohypophyseal hormone that causes myometrial contractions at term and promotes milk release during lactation. Oxytocin is used for induction or stimulation of labor. They are also used to manage the postpartum hemorrhage and atony, e.g. Pitocin.
Important things to know:
· Female reproductive organs lie inside the bony pelvis, while male organs lie mainly outside the pelvis.
· Menstruation occurs due to loss of functional layer of the endometrium if conception does not take place. It lasts for an average of 3 to 6 days.
· The study of female reproductive system is called gynecology and the physician who specializes in it is called a gynecologist.
· In females, the reproductive cycle is called a menstrual cycle and is of approximately 28 days' duration; the ova is released in mid cycle.
· Obstetrics is the specialty concerned with pregnancy, parturition, or delivery of fetus and physician who specializes in this branch is known as obstetrician.
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Chapter VII - Obstetric Procedures