Módulo 2 Ginecología/Obstetricia Flashcards

Question

A 29-year-old woman comes to the physician for birth control counseling. She is sexually active and has been using condoms, but would like to switch to a different method. She has no medical problems. She had a left ovarian cystectomy 4 years ago. She takes no medications and has no allergies to medications. Physical examination, including pelvic examination, is normal. After a thorough discussion of the birth control options, the patient wishes to start on depot medroxy-progesterone acetate (DMPA). Which of the following is this patient most likely to experience while on this form of contraception? (A) Elevated circulating estrogen levels (B) Increased bone density (C) Increased HDL cholesterol (D) Menstrual abnormalities (E) Pregnancy

Answer 1

Respuesta: D The correct **answer is D**. Depot medroxyprogesterone acetate (DMPA) is an injectable contraceptive given intramuscularly every 3 months. It is a synthetic progestin that provides contraception by inhibiting ovulation and creating an inhospitable environment in the female genital tract for conception (e.g., thickened cervical mucus). The most common side effects are menstrual abnormalities. Irregular bleeding patterns, including spotting, occur frequently in the first few months of use. Amenorrhea is also frequent and increases in incidence as the duration of therapy increases. Another major side effect of DMPA is weight gain, with the average user experiencing gains of approximately 3-5 pounds. Other adverse effects may include headache, decreased libido, tiredness, depression, and hair loss. Women should be counseled regarding these effects prior to starting this contraception. DMPA does not cause an elevation of circulating estrogen levels (**choice A**). On the contrary, DMPA has been shown to cause decreased circulating estrogen levels. These decreased levels are believed to result from the central hypothalamic suppression that DMPA causes, which decreases ovarian activation and estrogen production. DMPA does not cause increased bone density (**choice B**). In fact, DMPA has been shown to lead to decreased bone density over time, likely secondary to the decreased estrogen levels. However, this decreased bone density on DMPA has not yet been proven to lead to an increased rate of fractures. DMPA does not cause increased HDL cholesterol (**choice C**), but rather has been shown to decrease HDL (or “healthy”) cholesterol levels. DMPA is less likely to lead to pregnancy (**choice E**) compared with many other forms of contraception. Administration of 150 mg every 3 months has been shown to prevent pregnancy very effectively, with pregnancy rates approximately 0.3 per 100 women per year.

Answer 2

Respuesta: B The correct **answer is B**. Antibiotic prophylaxis is important for certain operations in obstetrics and gynecology. Vaginal hysterectomy is one gynecologic procedure for which prophylactic antibiotics have been proven to be of benefit in the prevention of infection. The goal of antibiotic prophylaxis in a vaginal hysterectomy is to have the antibiotics present in the tissue prior to the opening of the vaginal cuff, because vaginal organisms can gain entrance to the peritoneal cavity at that point. When antibiotics are administered 30 minutes prior to surgery, there is sufficient time for the antibiotics to reach the appropriate tissues and provide prophylaxis. No medications are needed (**choice A**) during many procedures. However, during vaginal hysterectomy, the risk of infection is increased compared with certain other procedures because there are numerous bacteria within the vagina that are not completely eradicated, even with an aggressive vaginal preparation prior to surgery. A beta blocker 30 minutes prior to surgery (**choice C**) would not be indicated in this patient. First, she has no cardiac history. Second, she has asthma; therefore, beta blockers would not be recommended. Antibiotics prior to closing (**choice D**) are not routinely indicated. In certain cases, e.g., a long operative time, a second dose of antibiotics should be given. Typically, however, one preoperative dose of antibiotics is sufficient. Antibiotics 6 hours after the surgery (**choice E**) would not be indicated. A postoperative antibiotic dose is sometimes needed for endocarditis prophylaxis in patients with cardiac disease. This patient has no cardiac disease

Answer 3

Respuesta: B The correct **answer is B**. The clinical diagnosis is fibroadenoma, which is seen in this age group with exactly the findings described. Fibroadenomas can be diagnosed with fine needle aspiration, which was not offered as a choice, or with ultrasonography. On confirmation of the diagnosis, the woman has the option for excision or continued clinical observation. Most women elect to have the mass removed, but it should be their choice. Clinical observation (**choice A**) is fine, once we know the lesion is a fibroadenoma. Otherwise, when the rare case of cancer comes along in this age group (yes, it can happen), diagnostic and therapeutic delays would be inexcusable. If a mammogram (**choice C**) were ordered, the physicians in the radiology department would have a good laugh. They do not perform mammograms in women younger than 20. The breast tissue is too dense in this population, and the study is not useful. Ultrasonography is a better option. Incisional biopsy (**choice D**) would be too aggressive to make the diagnosis and not complete enough to actually serve as treatment. If one elects a surgical approach for a 2-cm mass, one should take it all out. Excisional biopsy (**choice E**) would be better than incisional biopsy, but it would be an even more aggressive way to confirm the clinical diagnosis and would not allow the patient the choice of therapy

Answer 4

Respuesta: B The correct **answer is B**. When an ectopic pregnancy ruptures, there is often a significant amount of bleeding into the peritoneum. When a hemoperitoneum occurs, the blood can track upward and irritate the diaphragm. This diaphragmatic irritation is perceived by the patient as shoulder pain because of the phenomenon of referred pain. Referred pain describes the process by which pain in one area of the body is perceived as pain somewhere else (or referred to somewhere else) because of the nerve pathways that innervate the body. The same phenomenon is seen in myocardial infarction; patients often complain of jaw or arm pain. Thus, in a patient who is at risk for ectopic pregnancy, the complaint of shoulder pain may signal that the ectopic has already ruptured and there is enough of a hemoperitoneum to cause diaphragmatic irritation. This patient has an hCG of 5500 mIU/dL, nothing in the uterus on ultrasound (a pregnancy should be seen at an hCG of approximately 1500 mIU/dL), and significant free fluid (likely blood). She therefore almost certainly has an ectopic pregnancy, and the shoulder pain is caused from diaphragmatic irritation. A diaphragmatic ectopic pregnancy (**choice A**) is extraordinarily rare, if not impossible. Irritation from blood along the diaphragm causes referred pain to the shoulder-the presence of the ectopic on the diaphragm is not necessary. Malingering (**choice C**) should never be assumed until all other possibilities have been explored. The complaint of shoulder pain may, at first glance, seem odd. However, when one understands the phenomenon of referred pain it makes sense, and the patient is not incorrectly labeled a malingerer. A rotator cuff tear (**choice D**) can certainly cause shoulder pain. However, it is unlikely that this patient suddenly tore her rotator cuff halfway through the examination. Much more likely is that diaphragmatic irritation is causing her shoulder pain.

Answer 5

Respuesta: B The correct **answer is B**. This patient has a presentation that is classic for endometriosis. Endometriosis is a condition in which implants of endometrial glands and stroma are found outside of their normal location within the endometrial lining of the uterine cavity. In endometriosis, these implants are often found along several sites in the pelvis, including the anterior and posterior cul-de-sac, the tubes and ovaries, and the pelvic sidewalls bilaterally. Endometriotic implants have also been found in the lung and kidney. The classic triad of findings in endometriosis is dysmenorrhea, dyspareunia, and dyschezia (painful defecation). Definitive diagnosis is made with laparoscopy and biopsy of the lesions. At laparoscopy, the lesions can have a number of appearances, including powder-burn lesions, red and blue lesions, fibrotic lesions, or cystic lesions. There is a strong association between endometriosis and infertility. There is no proven association between endometriosis and basal cell carcinoma (**choice A**). Patients with endometriosis do not tend to have lengthy menstrual cycles (**choice C**). In fact, many patients with endometriosis have short menstrual cycles (<28 days). There is no proven association between endometriosis and lung cancer (**choice D**). Patients with endometriosis typically do not have menorrhagia (**choice E**). In fact, patients with endometriosis tend to have a lighter menstrual flow than do women without the condition.

Answer 6

Respuesta: B The correct **answer is B**. Approximately 20 to 25% of women will have first-trimester bleeding, and the chief concern is with ectopic pregnancy and spontaneous abortion. Of those women, about 50% will go on to have a spontaneous abortion (miscarriage). However, once fetal cardiac activity is seen, the risk of spontaneous abortion is around 10%. This patient has fetal cardiac activity and a normal exam and ultrasound. Therefore, she should be counseled that her risk of miscarriage is approximately 10%. To state that there is no risk of miscarriage (**choice A**) would not be correct. This is never appropriate counseling because in any pregnancy there is a risk of miscarriage, no matter how normal or healthy the pregnancy may seem. To state that there is an approximately 50% (**choice C**) or 75% (**choice D**) risk of miscarriage would be incorrect. As stated above, the risk of miscarriage with vaginal bleeding in the first trimester when fetal cardiac activity is present is approximately 10%. To state that miscarriage is almost certain (**choice E**) would not be correct.

Answer 7

Respuesta: B The correct **answer is B**. Sickle cell anemia results when a person has two copies of the sickle gene. This gene is on chromosome 11 and represents a mutation of the normal beta hemoglobin gene. The gene that codes for sickle hemoglobin has a single base pair substitution that results in coding for the amino acid valine rather than the glutamic acid, which is present in the normal beta globin chain. This amino acid substitution results in a hemoglobin that is susceptible to sickling at times of stress, infection, or decreased oxygen tension. These patients have sickle crises, which are acute, painful episodes believed to be associated with sickling in the microcirculation. They also may have increased susceptibility to infection, leg ulcers, autosplenectomy, thromboses, and cerebrovascular accidents. The disease is transmitted in an autosomal recessive fashion and is most common among persons of African descent. This patient has the sickle trait and so does her partner. Therefore, the child has a 25% chance of being born with sickle cell anemia. This disease will not affect the fetus in utero; fetal hemoglobin, which does not have a beta globin chain, is the primary hemoglobin type in the fetus. However, because of the risk of sickle cell anemia, some patients wish to have genetic testing performed. Chance of 0% (**choice A**) is incorrect. With a disease that is transmitted in an autosomal recessive fashion, when both parents have the trait, they have a 25% chance of having offspring affected with the disease. If one parent does not have the trait, then the chance of having offspring with the disease would be 0%. Chance of 50% (**choice C**) is incorrect. This couple has a 50% chance of having a fetus with sickle trait-that is, one normal copy of the beta-hemoglobin gene and one copy for sickle hemoglobin-but only a 25% chance of having a child with sickle disease. Chance of 75% (**choice D**) is incorrect for the above-given reasons. Chance of 100% (**choice E**) is incorrect. With an autosomal recessive disease, only if both partners have the disease is the likelihood 100% that the offspring will have the disease.

Answer 8

Respuesta: A The correct **answer is A**. Exposure to radiation, particularly in the form of an x-ray, is a major cause of anxiety for pregnant patients. There is a generally held belief that exposure to any radiation during pregnancy will lead to miscarriage or birth defects. There is no evidence, however, of any increase in spontaneous abortion or fetal anomalies at doses of radiation less than 5 rad. This dose is above the level of radiation exposure of diagnostic procedures. The fetal exposure from a chest x-ray with 2 views is approximately 0.05 mrad. This amount is several orders of magnitude below the 5 rad limit. Therefore, it is currently believed that x-ray exposure from any single diagnostic procedure will not cause harm to the fetus. This patient has signs and symptoms consistent with pneumonia and could therefore benefit from a chest x-ray. She should be reassured that the exposure to the fetus from a chest x-ray is minimal and has not been shown to cause birth defects or fetal loss. A chest x-ray exposes the fetus to minute amount of radiation compared with the amount needed to cause birth defects (**choice B**). There is no evidence that the exposure of 0.02 to 0.07 mrad of radiation caused by a chest x-ray leads to spontaneous abortion (**choice C**). To state that when chest x-ray has occurred, fetal pneumonia is more common (**choice D**) is incorrect. The presence or absence of a fetal infection is not dependent on a chest x-ray being performed to evaluate for maternal pneumonia. To state that when chest x-ray has occurred, termination should be considered (**choice E**) is incorrect. Exposure to x-ray during pregnancy is not an indication for therapeutic abortion.

Answer 9

Respuesta: E The correct **answer is E**. This patient has signs and symptoms that are suggestive of pulmonary embolism (PE). The most common presenting symptom for PE is shortness of breath, followed by pleuritic chest pain, apprehension, and cough. This patient has shortness of breath and pleuritic chest pain. On physical examination, tachypnea and tachycardia are the most common findings. This patient has tachycardia on the ECG, but not on manual pulse check, and has no tachypnea. However, given her complaints, her tachycardia, the increased likelihood of PE in pregnancy, and the catastrophic outcome that can result from an undiagnosed PE, doing a ventilation-perfusion ( ) scan makes sense in this patient. Many patients are reluctant to undergo a scan during pregnancy because they are concerned about radiation exposure of the fetus. These patients should be reassured that a scan leads to approximately 50 mrad of radiation exposure to the fetus. Exposure to less than 5 rad is not associated with spontaneous abortion or fetal anomalies. Antibiotic therapy (**choice A**) is not indicated in this patient. Although she does have dyspnea and tachycardia, she has no fever. PE must be ruled out prior to presumption of infection and administration of antibiotics. Warfarin therapy (**choice B**) is contraindicated during pregnancy. In the first trimester, warfarin can lead to chondrodysplasia punctata, which includes nasal hypoplasia, bony abnormalities, and mental retardation. In the second and third trimesters, it can also lead to fetal structural abnormalities and clotting difficulties. Heparin therapy (**choice C**) can be used during pregnancy. In this case, however, it is important to first diagnose PE prior to instituting heparin therapy. Pulmonary ultrasonography (**choice D**) is not used to evaluate for PE.

Answer 10

Respuesta: B The correct **answer is B**. Patients who are diagnosed with gestational diabetes are known to be at increased risk for the eventual development of overt diabetes. In fact, there is an approximately 50% likelihood that a woman with gestational diabetes will develop overt diabetes within the next 20 years. Therefore, women with gestational diabetes should be screened postpartum to determine whether they have diabetes so that prompt intervention can be initiated. To state that no postpartum follow-up is necessary (**choice A**) is incorrect. One of the benefits of screening for gestational diabetes in pregnancy is to identify women who may eventually develop overt diabetes. To start either oral hypoglycemics (**choice C**) or subcutaneous insulin (**choice D**) at the 6-week postpartum visit would be incorrect. This patient may not have diabetes and may never develop diabetes. To start her on oral hypoglycemics or subcutaneous insulin on the basis of her gestational diabetes would therefore not be proper. She should, however, be screened for diabetes at the 6-week postpartum visit. To refer the patient for pancreatic transplantation after her 6-week postpartum visit (**choice E**) would not be correct management.

Answer 11

Respuesta. D The correct **answer is D.** This patient presents with signs and symptoms most consistent with imperforate hymen. With an imperforate hymen, there is no egress for the monthly menstrual flow. Therefore, the patient will often complain of monthly cramping. Because there is no hormonal abnormality, the patient will have normal breast development as well as axillary and pubic hair. Pelvic examination will sometimes show a bulge as the monthly menstrual flow accumulates in the vagina. Rectal examination may reveal an anterior bulge, as the accumulation in the vagina can be palpated through the rectum. Management is with hymenectomy to allow for the egress of the monthly menstrual flow. Colon cancer (**choice A**) is unlikely in an otherwise healthy 14-yearold, and this patient’s signs and symptoms are more consistent with imperforate hymen. Ectopic pregnancy (**choice B**) is extremely unlikely with a negative hCG. Ectopic pregnancies almost never present as a bulge in the vagina, as they are usually located in the fallopian tube. Endometriosis (**choice C**) can present with monthly dysmenorrhea. However, this patient also has a bulge in the vagina, which is more consistent with imperforate hymen. Vaginal cancer (**choice E**) is unlikely in an otherwise healthy 14- year-old. This patient has monthly dysmenorrhea and a bulge in the vagina, both of which are most consistent with imperforate hymen.

Answer 12

Respuesta: E The correct **answer is E**. This patient has fibroids (leiomyomata). Fibroids are believed to be monoclonal tumors arising from uterine smooth muscle cells. Most often they are asymptomatic. When they are symptomatic, the symptoms include pain, pressure, urinary symptoms, or irregular uterine bleeding. This patient has significant menorrhagia causing her to have anemia to a hematocrit of 29%. She does not wish to have any more children; therefore, hysterectomy would be the most appropriate next step in management. Hormone replacement therapy (HRT) (**choice A**) would not be appropriate for this patient. This patient is neither postmenopausal nor estrogen deficient, so HRT would not be indicated. Diagnostic laparoscopy (**choice B**) would not be appropriate for this patient. This procedure is used for diagnosis in cases of acute or chronic pelvic pain or ectopic pregnancy. In this patient, the diagnosis is clear, given her findings on physical examination and ultrasound. Myomectomy (**choice C**) can be used in the treatment of fibroids, but it is usually reserved for patients who wish to preserve their childbearing potential. Myomectomy is usually quite effective in removing the fibroids; however, 25 to 50% of patients will have a recurrence, and as many as 10% of patients will require a second operation. This patient does not wish to preserve her uterus; therefore, hysterectomy would be preferred over myomectomy. Tubal ligation (choice D) would effectively address this patient’s desire not to have any more children; however, it would not address her pelvic pressure and menorrhagia.

Answer 13

Respuesta. D The correct **answer is D**. This patient has the signs and symptoms most consistent with a complete hydatidiform mole, which is one type of gestational trophoblastic disease. Other types include partial mole and choriocarcinoma. Patients with a complete mole often present with complaints of bleeding. Physical examination is typically significant for a uterus that is larger than the dates of the pregnancy would predict. Diagnosis is most often made by ultrasound, with the appearance of multiple echogenic areas. This pattern is usually described as a “snowstorm.” Management of a complete mole is with dilation and evacuation. This effectively removes the molar tissue from the patient. These patients then need close follow-up, with the serum hCG level being followed to ensure that there is no persistent or metastatic molar tissue. Expectant management (**choice A**) is not appropriate for a patient with a complete mole. These patients need therapy to prevent spread of the disease and/or the development of preeclampsia, hyperthyroidism, or other metabolic abnormalities. Folic acid supplementation (**choice B**) is not the next most appropriate step in management for someone with a complete mole. There is some evidence of a link between folic acid deficiency and complete mole. However, once a mole has been diagnosed, treatment is with dilation and evacuation. Methotrexate therapy (**choice C**) can be used to treat a persistent or metastatic complete mole. However, the first step in management is with dilation and evacuation. Laparotomy (**choice E**) is usually not necessary for the treatment of complete mole. Occasionally, some patients will elect or require hysterectomy for definitive treatment, but most cases can be treated with dilation and evacuation.

Answer 14

Respuesta: D The correct **answer is D**. In an adolescent, many of the initial menstrual cycles will be anovulatory. Anovulatory cycles put the woman at greater risk for menorrhagia, as there is often an excess build-up and loss of synchronicity of the endometrium when compared with an ovulatory cycle. As long as the episode of bleeding is not too excessive or causing any hemodynamic compromise, the oral contraceptive pill (OCP) is appropriate treatment. However, one should not immediately assume that acute vaginal bleeding in an adolescent is due to an anovulatory cycle. It is most important to check an hCG to establish the patient’s pregnancy status. History should focus on any bleeding disorder, history of trauma, or medications taken. This patient most likely has excessive bleeding from an anovulatory cycle. Her hematocrit is low (30%), and she still has some oozing; therefore, treatment is warranted. Treatment with the OCP should help to stabilize her endometrium and stop her bleeding. Blood transfusion (**choice A**) would not be indicated in this patient. Blood transfusions should be reserved for patients with very low hematocrits and signs of hemodynamic compromise. This patient has a hematocrit of 30% and stable vital signs. The risks of blood transfusion (e.g., infection and transfusion reaction) outweigh any benefit to be gained in this case. Fresh frozen plasma (**choice B**) is indicated in situations in which clotting factors are needed. This patient has a normal PT and PTT and no history of a bleeding disorder; therefore, fresh frozen plasma would not be indicated. IV conjugated estrogens (**choice C**) is the correct management in cases of acute bleeding caused by anovulation when the hematocrit is very low or when there are signs of hemodynamic compromise. IV conjugated estrogens work at both the capillary level and the level of the endometrium to stop bleeding. This patient, with her stable vital signs and stable hematocrit, would not need IV conjugated estrogens. Platelet transfusion (**choice E**) would not be the most appropriate next step in management, as this patient has a normal platelet count. She also has no history of a bleeding disorder to suggest that her platelets are functionally ineffective

Answer 15

Respuesta: A The correct **answer is A. **This patient has the constellation of signs and symptoms consistent with severe preeclampsia: hypertension, edema, and proteinuria. Her headache, visual changes, and epigastric pain indicate that her condition is severe and troublesome, because these symptoms often precede the development of convulsions (eclampsia). The management of severe preeclampsia is delivery of the fetus, as this is the only way the disease process will resolve. Magnesium sulfate should be started immediately and continued for 24 hours postpartum to prevent eclampsia. Hepatitis (**choice B**) can present with epigastric or right upper quadrant pain. However, this patient has a variety of other signs and symptoms that make severe preeclampsia the diagnosis, and eclampsia the most immediate concern. Migraine (**choice C**) can present with headache and visual changes. Again, however, this patient also has elevated blood pressure, edema, proteinuria, and epigastric pain. This constellation of symptoms is more consistent with preeclampsia than with migraine. Myocardial infarction (**choice D**) occurs during pregnancy at a rate of less than 1 in 10,000. This would not be of most immediate concern in this patient. Systemic lupus erythematosus (**choice E**) can present with hypertension and proteinuria. However, this patient has these findings as well as other signs and symptoms that make eclampsia a more immediate concern.

Answer 16

Respuesta: A The correct **answer is A**. Women with type 1 diabetes mellitus are at increased risk of having offspring with congenital malformations. Various studies have shown that these fetuses are at a two- to six-fold increased risk compared with normal pregnancies. Anomalies commonly found in infants of diabetic mothers (IDM) include those of the cardiac, renal, and central nervous systems. Sacral agenesis, the most characteristic anomaly of diabetic embryopathy, is found 200-400 times more commonly in IDM. Most of these anomalies arise during the first 7 weeks of gestation as the fetal organs are forming. Women at this stage of pregnancy often do not yet know that they are pregnant. Therefore, it is essential that women with type 1 diabetes be counseled regarding fetal anomalies prior to conception. Good glycemic control prior to conception decreases the risk of spontaneous abortions and congenital malformations and increases the likelihood of good pregnancy outcomes. Folic acid (4 mg/day) may help prevent neural tube defects in overt diabetics. If women with type 1 diabetes are given management and counseling in the first trimester (**choice B**) regarding fetal anomalies, then it is likely that the window of opportunity to attain good glycemic control during organogenesis will be missed. Again, organ formation and development occur during the first 7 weeks of pregnancy. Many patients do not realize they are pregnant until after 7 weeks’ gestation. Also, those who do present prior to 7 weeks may have difficulty in achieving good glycemic control in a short time span. Therefore, good glycemic control will ideally be achieved preconceptionally. A woman with type 1 diabetes should have an ultrasound at around 18 weeks to evaluate for anomalies. However, waiting until just prior to (**choice C**) or after (**choice D**) an 18-week ultrasound or until the third trimester (**choice E**) is too late to counsel the patient regarding fetal anomalies

Answer 17

Respuesta: B The correct **answer is B**. This patient has a history that is most consistent with cervical incompetence, which is defined as painless cervical dilation in the second trimester. This definition is meant to distinguish cervical incompetence from preterm labor, in which there is progressive cervical dilation with painful contractions. In actual practice, many women present with a history of cervical dilation and some “cramping.” In these cases, it can be difficult to determine whether the process was cervical incompetence or preterm labor. When a patient has a history of cervical incompetence, a cerclage may be placed. This cerclage is a suture that is placed at the level of the internal os (a Shirodkar cerclage) or a purse string suture that is placed as high as possible (a McDonald cerclage). The idea is that the suture will support the cervix and maintain its “competence.” Timing of cerclage placement is important. There are two kinds of cerclages to consider when discussing timing. One is a prophylactic cerclage that is placed based on the woman’s history. The second is an emergency cerclage that is placed based on findings of cervical dilation with bulging membranes. This patient would qualify for a prophylactic cerclage, as she is at 6 weeks’ gestation. To place a cerclage immediately (**choice A**) runs the risk of performing a procedure on a patient who may have a spontaneous abortion. It is better to wait until the pregnancy is well established (e.g., late first or early second trimester, or 10-14 weeks) so that there is less likelihood of performing a cerclage on a woman who was going to miscarry anyway. To wait until 20-24 weeks (**choice C**) would not be correct because this may be too late. The process of incompetence may be under way at this point in the pregnancy. To wait until 24-28 weeks (**choice D**) or 32-36 weeks (**choice E**) would also be incorrect. Again, the process of incompetence may have already started. Also, performing a cerclage this late in the pregnancy runs the risk of iatrogenic prematurity by stimulating preterm labor or rupturing the membranes. A woman, regardless of her history, who makes it to 24 or 32 weeks has a good chance of not delivering prematurely. Cerclage placement carries the risks of ruptured membranes, infection, or preterm labor.

Answer 18

Respuesta: C The correct **answer is C**. This patient is at increased risk for developing a postcesarean wound infection because of her obesity. The main risk factors are poor surgical technique, low socioeconomic status, extended duration of labor and ruptured membranes, chorioamnionitis, obesity, type 1 diabetes mellitus, immunodeficiency, corticosteroid therapy, and immunosuppressive therapy. Postcesarean wound infections are usually caused by staphylococci or streptococci. Treatment should be directed against gram-positive organisms, with nafcillin or vancomycin if the patient is allergic to penicillins. This patient has a distant history of asthma (**choice A**) and she has taken no medications for many years. Thus, her asthma does not increase her risk for postcesarean wound infection. However, if she were to have more active asthma and had been taking steroids, this immunosuppression would place her at greater risk of wound infection. Low socioeconomic status, not high socioeconomic status (**choice B**), is a risk factor for postcesarean wound infection. Short duration of ruptured membranes (**choice D**) is not a risk factor for wound infection. When the membranes are ruptured for a long time, there is a greater risk for the development of both endometritis and wound infection. Short operative time (**choice E**) is not a risk factor for wound infection. Certain studies have shown that long operative times make the patient more likely to develop postoperative infections.

Answer 19

Respuesta: A The correct **answer is A.** One of the most serious complications of the oral contraceptive pill (OCP) is deep venous thrombosis (DVT). OCPs, particularly the estrogen component, are known to make some patients hypercoagulable. Patients who are especially at risk are those with an inherited resistance to activated protein C and those with the factor V Leiden mutation. However, even in patients without these traits, the OCP can lead to an increased risk of DVT, pulmonary embolus, and cerebral thrombosis. All patients who are started on an OCP should be warned and educated regarding the symptoms of a blood clot. If leg pain and swelling develop, the main concern is DVT, and that patient must be evaluated, e.g., with duplex Doppler studies. To prescribe acetaminophen (**choice B**) over the phone without first evaluating the patient would not be appropriate. As noted above, DVT is a major concern in women taking the OCP with leg pain and swelling. Delay could lead to propagation of a thrombus, embolism, and even death. To recommend warm soaks and evaluation in 1 week (**choice C**) would not be appropriate. Again, this patient may have a DVT, and delay in diagnosis and treatment could result in significant morbidity or mortality. To schedule a pelvic ultrasound (**choice D**) would be improper management. Although this patient is a woman, her complaint is leg pain and swelling. The appropriate study would be ultrasound of the leg, or another study, to evaluate for the presence of a thrombus in the lower extremities. Prescribing Coumadin (**choice E**) would not be appropriate. The patient must be evaluated first to determine whether she has a DVT. If a thrombus is discovered, then anticoagulation would be appropriate.

Answer 20

Respuesta: D The correct **answer is D**. A patient with a prior cesarean delivery is at increased risk of uterine rupture. When the prior uterine scar is from a classic cesarean delivery (i.e., a vertical uterine incision involving the upper, contractile portion of the uterus), the risk of uterine rupture with labor is approximately 12%. With such a high risk of uterine rupture, patients who have had a previous classic cesarean delivery are not allowed to have a VBAC (vaginal birth after cesarean). Vaginal birth is contraindicated. In contrast, patients with a prior low transverse uterine incision or low vertical uterine incision have a much lower rate of uterine rupture (around 1 to 2%); these patients are allowed a trial of labor. To state that cesarean delivery is contraindicated (**choice A**) is incorrect. Cesarean delivery is, in fact, mandated in patients with a prior classic cesarean delivery, and it is vaginal delivery that is contraindicated. To state that forceps-assisted vaginal delivery is recommended (**choice B**) or that vacuum-assisted vaginal delivery is recommended (**choice C**) is not correct. Vaginal delivery of any type is contraindicated in a woman with a prior classic cesarean delivery. To state that vaginal birth is not contraindicated (**choice E**) is incorrect. As explained above, vaginal birth is contraindicated after a prior classic cesarean delivery

Answer 21

Respuesta: E The correct **answer is E**. Newborns delivered by cesarean have a higher rate of transient tachypnea compared with newborns delivered via vaginal delivery. One hypothesis for this finding is that vaginal delivery leads to compression of the fetal thorax and removal of pulmonary fluid, which can cause transient tachypnea of the newborn. Also, some would argue that other factors in the process of vaginal delivery better prepare the newborn for extrauterine life from a pulmonary standpoint. Most of these cases resolve without serious sequelae. Fracture of the fetal clavicle (**choice A**) and fracture of the fetal femur (**choice B**) can occur during a cesarean delivery but are more common with a vaginal delivery. However, when obtaining consent from a patient for cesarean delivery, it is important to inform her that there is a risk of injury to the baby. Many patients are under the mistaken assumption that cesarean delivery implies no risk whatsoever of injury. Maternal perineal trauma (**choice C**) is far more likely to occur with a vaginal than with a cesarean delivery. An uncomplicated cesarean delivery should lead to no perineal trauma at all. Some physicians argue that because the perineal trauma that women experience with a vaginal delivery can lead to incontinence and pelvic organ prolapse in the future, women should be allowed to choose cesarean delivery as an elective procedure. However, this is not the standard of care for most practitioners or institutions. Shoulder dystocia (**choice D**) is far more likely to occur with a vaginal delivery than with a cesarean delivery. However, there is still some risk of shoulder dystocia and fetal injury during a cesarean delivery.

Answer 22

Respuesta: A The correct **answer is A**. This patient has two issues that must be addressed when considering a birth control option. The first is birth control. All of the options would address birth control, although the rhythm and withdrawal methods are not recommended because of their high failure rates. The second is prevention of sexually transmitted diseases (STDs). Of these options, only condoms can prevent the transmission of STDs. Along with the emphasis on condoms, this patient needs to be advised that her sexual behavior places her at risk for a number of STDs, including HIV, hepatitis B and C, herpes, Chlamydia, gonorrhea, syphilis, and trichomoniasis. The intrauterine device (IUD) (**choice B**) would be absolutely contraindicated in this patient. Her prior history of pelvic inflammatory disease (PID) and current sexual behavior place her at increased risk for contracting an STD. STDs (most notably Chlamydia and gonorrhea) in the setting of an IUD can lead to severe PID, sepsis, and even death. The oral contraceptive pill (OCP) (**choice C**) is an option for this patient. However, although use of the OCP will prevent pregnancy, it will do nothing to prevent STDs. Therefore, even if this patient does use the OCP, she must also use condoms. The rhythm (**choice D**) and withdrawal (**choice E**) methods are both associated with high failure rates. The rhythm method relies on timing intercourse during the period of the woman’s cycle in which ovulation is unlikely. The withdrawal method relies on the male partner withdrawing from the vagina prior to ejaculation. Both have prohibitively high failure rates and do not provide good protection from STDs.

Answer 23

Respuesta: C The correct **answer is C**. This patient is considered to have an appropriate weight, with a BMI of 20.6. BMI is calculated by dividing the prepregnant weight in kilograms by the height in meters squared. Thus, with a BMI of 20.6, she is neither overweight nor underweight. In a patient of normal weight, pregnancy should be associated with a weight gain of 25-35 lb. This weight gain is composed of fetal weight, amniotic fluid, uterine growth, placenta, breast enlargement, volume expansion, and increased fat stores. Patients usually gain about 5-10 pounds in the first 20 weeks of pregnancy and then roughly 1 pound per week for the final 20 weeks, although a wide range of weight changes in pregnancy are still compatible with good maternal and fetal outcomes. Several studies, however, do show increased complications with weight gains that are at the extreme high or low ends. A weight gain of 5-15 pounds (**choice A**) or 15-25 pounds (**choice B**) is considered less than recommended for a woman of normal body weight. Certain studies have shown that too low a weight gain is associated with low birthweight infants and preterm labor. However, for women who enter the pregnancy overweight (BMI of 26-29), the recommended gain is 15-25 pounds. For obese women (BMI greater than 29), the recommended gain is 15 pounds. A weight gain of 35-45 pounds (**choice D**) or 45-55 pounds (**choice E**) is considered more than recommended for a woman of normal body weight. Excessive weight gain has been linked to large-forgestational age infants and increased risk of cesarean delivery. However, for patients who enter the pregnancy underweight (BMI less than 19.8), the recommended gain is 28-40 pounds.

Answer 24

Respuesta: A The correct **answer is A**. Methotrexate, an inhibitor of the enzyme dihydrofolate reductase, can be used in certain cases to treat ectopic pregnancy. This enzyme is essential for the eventual production of purine and pyrimidine subunits of nucleic acid. By blocking this enzyme, methotrexate destroys the rapidly dividing cells of the ectopic pregnancy. However, certain patients are not considered eligible for methotrexate treatment. Many physicians consider this therapy contraindicated if the ectopic pregnancy has a certain size (e.g., greater than 3.5 cm), has an elevated hCG value (e.g., greater than 15,000 mIU/dL), or has cardiac activity. However, these criteria do vary depending on the institution and physician. Also, methotrexate can cause bone marrow depression as well as hepatotoxicity and nephrotoxicity. Therefore, patients with anemia, leukopenia, thrombocytopenia, elevated liver function tests, or elevated creatinine levels are also considered ineligible for methotrexate treatment. This patient has an elevated liver function test: her aspartate aminotransferase level is 110 U/L. A blood pressure of 110/70 mm Hg (**choice B**), a creatinine of 0.7 mg/dL (**choice C**), a hematocrit of 40% (**choice D**), and a platelet count of 200,000/mm3 (**choice E**) are all normal, and would not constitute a contraindication to methotrexate treatment in this patient.

Answer 25

Respuesta: A The correct **answer is A**. This patient, although she cannot remember having varicella, has evidence of prior infection and natural immunity. Most women who have no known history of varicella infection will have detectable antibodies. This patient’s immunity will protect her fetus from infection, and no further treatment is needed. Avoidance of possible infection (**choice B**) is a strategy for women without natural immunity. However, this patient has been shown to have immunity. In addition, this patient has a documented exposure. If she were without immunity, she would need to be treated with varicella zoster immunoglobulin in an effort to prevent infection or severe manifestations of infection. The incubation of varicella ranges from 10 to 20 days, with a mean of 14 days. This patient’s exposure does fall in the incubation stage, but she has documented immunity. Further immunologic testing (**choice C**) is not indicated. Fetal infection is usually very severe and may lead to fetal death. Elective termination should be offered to those who have evidence of fetal infection. Fortunately, fetal infection is very rare, occurring in less than 5% of infected mothers. Fetal infection is likely to have the worst outcome in those affected earlier than 20 weeks’ gestation. Ultrasound is used to look for signs of fetal infection, such as hydrops, microcephaly, limb anomalies, cardiac malformations, and intrauterine growth restriction. However, this mother has signs of immunity as discussed previously, and there is no risk of fetal infection. Termination of pregnancy (**choice D**) or an ultrasound (**choice E**) is not needed.

Answer 26

Respuesta: B The correct **answer is B**. This patient has preterm labor. This diagnosis can be made on the basis of her regular contractions and cervical change. The magnesium sulfate is a tocolytic designed to quiet the uterus and halt the preterm labor. The penicillin is given to prevent group B streptococcal (GBS) disease of the newborn should the patient deliver. Dexamethasone should also be given to reduce the risk of respiratory distress syndrome (RDS), intraventricular hemorrhage (IVH), and perinatal mortality. A large amount of data have accumulated over the past 3 decades, demonstrating that antenatal corticosteroids are effective in the prevention of RDS, IVH, and neonatal mortality. The two corticosteroids used are betamethasone and dexamethasone. They are similar in structure, have a half-life of approximately 72 hours, and cross the placenta in an active form. It is not necessary to add ampicillin (**choice A**) to this patient’s pharmacologic regimen. This patient is already on penicillin for GBS prophylaxis and further treatment with ampicillin is therefore not needed. Gentamicin (**choice C**) should not be added to this patient’s regimen. There is no evidence that this patient has chorioamnionitis, but if she did, she should be treated with gentamicin. However, in that case the fetus should also be delivered and tocolysis should not be given. Terbutaline (**choice D**) should not be added to this patient’s regimen. This patient is already on magnesium sulfate for tocolysis. The addition of another tocolytic would only place this patient at greater risk of complications. Tetracycline (**choice E**) is not used during pregnancy because of its effects on fetal teeth and bone.