Question 191#

A patient at 17 weeks' gestation is diagnosed as having an intrauterine fetal demise. She returns to your office 5 weeks later and has not had a miscarriage, although she has had some occasional spotting.

This patient is at increased risk for which of the following?

A. Septic abortion

Correct Answer C:
Disseminated intravascular coagulation (DIC) begins with excessive clotting. The excessive clotting is usually stimulated by a substance that enters the blood as part of a disease (such as an infection or certain cancers) or as a complication of childbirth, retention of a dead fetus, or surgery. As the clotting factors and platelets are depleted, excessive bleeding occurs.

DIC may appear to develop suddenly and usually causes bleeding, which may be very severe. If the condition follows surgery or childbirth, bleeding may be uncontrollable. Bleeding may occur at the site of an intravenous injection or in the brain, digestive tract, skin, muscles, or cavities of the body. If DIC develops more slowly, as in people with cancer, then clots in veins are more common than bleeding. 

Blood tests may show that the number of platelets in a blood sample has dropped and that the blood is taking a long time to clot. The diagnosis of DIC is confirmed if test results show diminished amounts of clotting factors and large quantities of proteins that are produced when clots are broken up by the body (fibrin degradation products).

Question 192#

The commonest cause of disseminated intravascular coagulation during pregnancy is:

A. Amniotic fluid embolism

Correct Answer B:

Disseminated intravascular coagulation (DIC) involves abnormal, excessive generation of thrombin and fibrin in the circulating blood. During the process, increased platelet aggregation and coagulation factor consumption occur. DIC that evolves slowly (over weeks or months) causes primarily venous thrombotic and embolic manifestations; DIC that evolves rapidly (over hours or days) causes primarily bleeding.

DIC occurs in the following clinical circumstances:

1. Complications of obstetrics, eg, abruptio placentae (most common), saline-induced therapeutic abortion, retained dead fetus or products of conception, or amniotic fluid embolism. Placental tissue with tissue factor activity enters or is exposed to the maternal circulation.
2. Infection, particularly with gram-negative organisms. Gram-negative endotoxin causes generation of tissue factor activity in phagocytic, endothelial, and tissue cells.

Question 193#

Which of the following physiologic changes occurs during a normal pregnancy?

A. Hyperuricemia

Correct Answer D:

Compared with pre-pregnancy values uric acid concentrations decreased significantly by 8 weeks gestation and this reduced level was maintained until about 24 weeks. Proteinuria changes little during pregnancy and if more than 500mg/24h is lost, a disease process should be suspected. Normally, the patient's blood pressure will not rise in pregnancy.

Glucosuria during pregnancy is not necessarily abnormal, may be explained by the increase in GFR with impairment of tubular reabsorption capacity for filtered glucose. Increased levels of urinary glucose also contribute to increased susceptibility of pregnant women to urinary tract infection. With increased minute ventilation, the gravida will have increased alveolar ventilation, leading to respiratory alkalosis.

Question 194#

At her first obstetric visit, a patient does not remember the date of her last menstrual period. She has not felt fetal motion. The fetal heartbeat is audible with the Doppler fetoscope but not with the DeLee stethoscope. At her second visit one month later she has just felt fetal quickening. The uterine fundus measure 17 cm.

Which one of the following would describe the state of gestation?

A. 10 to 12 weeks

Correct Answer C:

In pregnancy terms, the moment of quickening refers to the initial motion of the fetus in the uterus as it is perceived or felt by the pregnant woman. According to the Oxford English Dictionary, to "quicken" means "to reach the stage of pregnancy at which the child shows signs of life."

A woman pregnant for the first time (i.e. a primiparous woman) typically feels fetal movements at about 20-21 weeks, whereas a woman who has already given birth at least two times (i.e. a multiparous woman) will typically feel movements around 18 weeks.

Since as a rule of thumb, the fundal height (in centimeters) should roughly equal the number of weeks of pregnancy, this patient is probably at 16-20 weeks gestation.

Question 195#

All of the following are cardiovascular adaptations to pregnancy, except:

A. Cardiac output increases 33-45%

Correct Answer C:

The normal physiological changes in pregnancy are as follows:

1. Cardiac output rises 30 to 50 percent above baseline (choice A). It peaks by the end of the second trimester, after which it reaches a plateau until delivery. The change in cardiac output is mediated by 1) increased preload due to the rise in blood volume, 2) reduced afterload due to a fall in systemic vascular resistance, 3) a rise in the maternal heart rate by 10 to 15 beats per minute (statement in choice C is incorrect) .
2. Stroke volume increases (choice B) during the first and second trimesters, but declines in the third trimester due to caval compression by the gravid uterus. The direct effect of pregnancy on cardiac contractility is controversial.
3. Blood pressure typically falls (choice D and choice E), usually reaching a nadir of 10 mm Hg below baseline by the end of the second trimester. The decline in blood pressure is mediated by a fall in systemic vascular resistance induced by hormonal changes and by the addition of a low-resistance circuit through the uteroplacental bed.