Obstetrics and gynecology

Obstetrics is the branch of medicine concerned with pregnancy and childbirth. Because most pregnancies are not problematic, the main role of an obstetrician is to monitor the health and progress of mother and fetus and to help deliver the baby during childbirth. Gynecology deals with the medical and surgical treatment of disorders of the female reproductive organs.

A common complication of pregnancy is a breech birth (A), in which the baby is bom buttocks first, rather than head first About 1 in 80 pregnancies results in twins, of which there are two types. In identical, or maternal, twins (B and right} both babies derive from a single egg and share the same placenta in the mother’s womb. Nonidentical, or fraternal, twins (C) originate from two separate eggs and each has its own placenta. Nearly all twins are born normally.

Gynecological disorders

Abnormalities of the menstrual cycle include amenorrhea (absence of periods); dysmenorrhea (painful periods); menorrhagia (heavy bleeding); irregular periods; and premenstrual syndrome (PMS), also known as premenstrual tension (PMT).

Although patient history and a physical examination including a pelvic examination reveal most abnormalities of vagina, uterus, and ovaries, blood tests may be necessary to identify specific hormonal abnormalities. In some cases, further evaluation may be necessary. This could include procedures such as colposcopy, endometrial biopsy, or dilatation and curettage (D and C).
A hysterectomy (surgical removal of the uterus) may be necessary if the womb is the site of a cancerous growth or if fibroids (benign tumors) are growing in the uterine muscle, or to treat otherwise uncontrollably heavy periods.

Cancer of the cervix of the uterus is among the easiest neoplasm (tumor) to detect, by means of a cervical smear test called a PAP test. This involves examining microscopic cells scraped from the cervix for precancerous cells. If present, precancerous tissue can be removed or destroyed to prevent its development into malignant cancerous tissue.

The commonest malignant tumor in women affects the breast. Usually breast cancer is first evident as a small, hard, painless lump. To treat it, the lump and the surrounding tissue must be removed. In certain cases, this extends to removal of the whole breast (mastectomy). Because the spread of the disease can be rapid and extensive, surgery may be followed by drug and radiation therapy. Eighty per cent of women in whom the disease is treated early are perfectly well five years after treatment. Cysts are another common cause of breast lumps. These are harmless, but must be distinguished from potentially dangerous growths by medical examination and mammography.

Infertility

Male infertility is usually caused by absent or decreased numbers of sperm in the semen, or by abnormalities in the sperm. Infertility in a woman may be hormonal or physical. The most common cause of the latter occurs if the Fallopian tubes are scarred or blocked, usually as a result of infection, which prevents the ovum passing to the uterus. Polyps or fibroids in the womb may also cause infertility by preventing implantation. The use of “fertility drugs,” which stimulate ovulation, may cure infertility. Alternatively, some cases of infertility can be treated by removing an ovum and fertilizing it outside the body, then implanting it when the developing embryo is viable. This is the technique known as in vitro fertilization.

Infertility is a problem that faces many couples who want to have children. Usually it is caused by faulty ovulation or imbalances in the complex cycle of hormonal changes in the woman. It can also occur if the man produces dead, unhealthy, or insufficient sperm. These two photographs show a healthy (left) and an unhealthy sperm.

Prenatal screening

During pregnancy, regular visits to a prenatal clinic are necessary to monitor weight gain, blood pressure, and ankle edema (swelling). Urine is tested for sugar, which may indicate diabetes, and for protein, which may suggest infection or preeclampsia. The growth of the uterus is regularly checked against the expected size, and if there is a rapid increase, an examination using ultrasound may detect twins or an excess of fluid. This technique is harmless to mother and baby.

Blood is tested for Rhesus factor incompatibility and immunity to various viral infections, including rubella (German measles). The latter is ordinarily a mild infection, but if a woman contracts it in the first four months of pregnancy, fetal abnormalities, such as deafness or blindness, can occur. Further monitoring includes tests for anemia and syphilis. A test for the presence of alphafetoprotein is usually also carried out to detect spina bifida. Amniocentesis in which a small amount of amniotic fluid is taken from the sac surrounding the fetus may be carried out whether or not there are signs of fetal abnormality. Cells in the fluid may indicate the possibility of hemolytic disease (from an untreated Rhesus negative mother), and chromosomal abnormalities such as Down’s syndrome (mongolism).

Other aspects of pregnancy

Iron and folate tablets are commonly prescribed for the mother, but other drugs should not be taken without medical supervision. Sometimes a miscarriage (spontaneous abortion) occurs for no apparent reason, although it may be a reaction to fetal abnormality or placental insufficiency.

An ectopic pregnancy occurs when a fertilized ovum implants outside the uterus, usually in a Fallopian tube. At about 10 weeks, the tube ruptures and an emergency operation must be performed.

A cervical smear test to detect the possible presence of precancerous cells is carried out on a sample of tissue from the neck of the womb. The cells in the sample are stained and examined using a microscope; a healthy sample has the appearance shown here. The presence of abnormal but precancerous cells allows the physician to begin treatment—with drugs or minor surgery—before the onset of a malignant cancer.

Complications of childbirth

During labor, the child is at risk from hypoxia (shortage of oxygen), and the baby’s heart rate is usually monitored to assess this risk. If there is severe fetal distress, or for certain other reasons, such as a misplaced placenta, or if the mother is ill, a Caesarean section may be performed as an emergency. In this, an incision is made in the abdomen and the baby is delivered through the lower section of the womb. Fortunately, however, such complications are rare.