A 25-year-old married white female comes to your office for a routine examination. She expresses some concern because she has not had a menstrual period in 6 months. She has been trying to get pregnant for over 2 years without success. Examination shows an obese woman with a central pattern to her obesity. She has a mild increase in facial hair, but the examination is otherwise normal, although the pelvic examination is difficult to perform because of her obesity. Her blood pressure is 138/90 mm Hg. A CBC, metabolic panel, and thyroid studies are all normal. Other laboratory findings include the following:
In addition to weight loss and exercise, which one of the following would improve her chances for conception?
Correct Answer C:
Polycystic ovary disease is probably the result rather than the cause of amenorrhea. Polycystic ovaries are thought to be the result of anovulation, which in turn is likely due to a combination of hyperinsulinemia and insulin resistance which leads to abnormal hypothalamic secretion of Gn-RH. This results in a high level of estrogen, causing anovulation. Patients have higher levels of LH and low to low-normal levels of FSH. Diagnostic criteria include definite or probable menstrual dysfunction, clinical evidence of increased androgens, and the exclusion of congenital adrenal hyperplasia. Findings which support the diagnosis include perimenarchal onset, insulin resistance, and elevated LH/FSH ratio, and polycystic ovaries on ultrasonography. As many as 25% of normal women may have polycystic ovaries when examined by ultrasonography but ultrasonography alone should not be the sole criterion for diagnosis. The use of metformin reduces insulin resistance and may normalize menstruation and restore ovulation.
A 30-year-old white gravida 2 para 1 who has had no prenatal care presents for urgent care at 33 weeks gestation. Her symptoms include vaginal bleeding, uterine tenderness, uterine pain between contractions, and fetal distress. Her first pregnancy was uncomplicated, with a vaginal delivery at term.
Which one of the following is the most likely diagnosis?
Correct Answer D: Late pregnancy bleeding may cause fetal morbidity and/or mortality as a result of uteroplacental insufficiency and/or premature birth. The condition described here is placental abruption (separation of the placenta from the uterine wall before delivery).
There are several causes of vaginal bleeding occurring in late pregnancy that might have consequences for the mother, but not necessarily for the fetus, such as cervicitis, cervical polyps, or cervical cancer.
Even advanced cervical cancer would be unlikely to cause the syndrome described here. The other conditions listed may bring harm to the fetus and/or the mother.
Uterine rupture usually occurs during active labor in women with a history of a previous cesarean section or with other predisposing factors, such as trauma or obstructed labor. Vaginal bleeding is an unreliable sign of uterine rupture and is present in only about 10% of cases. Fetal distress or demise is the most reliable presenting clinical symptom. Vasa previa (the velamentous insertion of the umbilical cord into the membranes in the lower uterine segment) is typically manifested by the onset of hemorrhage at the time of amniotomy or by spontaneous rupture of the membranes. There are no prior maternal symptoms of distress. The hemorrhage is actually fetal blood,, and exsanguination can occur rapidly. Placenta previa (placental implantation that overlies or is within 2 cm of the internal cervical os) is clinically manifested as vaginal bleeding in the late second or third trimester, often after sexual intercourse. The bleeding is typically painless, unless labor or placental abruption occurs.
A 29-year-old gravida 2 para 1 presents for pregnancy confirmation. Her last menstrual period began 6 weeks ago. Her medical history is significant for hypothyroidism, which has been well-controlled on levothyroxine (Synthroid), 150 mcg daily, for the past 2 years.
Which one of the following would be the most appropriate next step in the treatment of this patient’s hypothyroidism during her pregnancy?
Correct Answer C: Maternal hypothyroidism can have serious effects on the fetus, so thyroid dysfunction should be treated during pregnancy. Because of hormonal and metabolic changes in early pregnancy, the levothyroxine dosage often needs to be increased at 4-6 weeks gestation, and the patient eventually may require a 30%-50% increase in dosage in order to maintain her euthyroid status.
A known hypothyroid patient on thyroxine 100 µg/day presents to her physician with a month history of amenorrhea. With appropriated work-up, pregnancy was confirmed. Her body weight is 85kg.
Which of the following management options is most appropriate?
Correct Answer B: Immediate step-up of the dose of thyroxine (choice B) is recommended when hypothyroid patients get pregnant because pregnancy is known to increase thyroxine requirement. Maternal thyroxine transferred through the placenta is essential for normal development of the fetal brain. The fetal thyroid gland starts functioning only later towards the end of the first trimester when the hypothalamo-pituitary-thyroid axis starts working. For this reason, the dose of thyroxine should immediately be increased to 2 µg/kg body weight or 170 µg for this patient.
→ Immediate replacement of thyroxine (T4) with triiodothyronine (T3) (choice A) is the incorrect answer. The fetal brain uses only thyroxine produced locally by deiodination of T4 and cannot use maternal T3. Thus, T3 is not used for treatment of hypothyroidism in pregnancy.
→ Immediate decrease of the dose of thyroxine (choice C) is not an appropriate management option for this patient. Pregnancy increases thyroxine requirement and the dose of thyroxine should be increased rather than decreased.
→ Continuation of current thyroxine dose till the end of the first trimester (choice D) is not an appropriate management option. Thyroxine is most needed during the period of organogenesis i.e. during the first trimester.
→ Continue the same dose of thyroxine throughout pregnancy (choice E) is not the appropriate management option. Pregnancy increases thyroxine requirement and the dose of thyroxine should be increased during pregnancy.
Key point:
An obstetric clinic is screening pregnant women for gestational diabetes mellitus with the 1-hour 50g Oral Glucose Challenge Test (OGCT). Patients who test positive on OGCT are further tested by the standard 3-hour Glucose Tolerance Test (OGTT) to confirm or exclude the diagnosis of GDM. For the screening test, OGCT, the clinic decided to use 7.2 mmol/L as a cut-off value of the 1-hour plasma glucose for defining a positive test instead of 7.7 mmol/L. Such change in cut-off value is known to increase sensitivity and decrease specificity of the test.
Which of the following outcomes is expected from this change in cut-off point?
When the cut-off point is lowered and test sensitivity increases, the number of patients expected to be left undiagnosed will decrease (choice C). The higher the test sensitivity, the higher is the number of true positives and the lower the number of false negatives. Thus, fewer patients with GDM will be left undiagnosed (false negatives). The table below further illustrates this change in outcome.
GDM is gestational diabetes mellitus; OGCT is oral glucose challenge test; OGTT is Oral Glucose Tolerance Test.
Sensitivity = a / (a + c): an increase in sensitivity increases “a” and decreases “c”.
Specificity = d / (b + d): a decrease in specificity decreases “d” and increases “b”.
→ The number of patients that will be tested by the definitive OGTT is expected to increase rather than decrease (choice A). Patients who will be tested by the OGTT are those who test positive with the screening OGCT. This includes the true positive and the false positive patients. Both of these categories will increase. The increase in sensitivity would increase the number of true positives and the decrease in specificity would increase the number of false positives. Thus, we will end up testing more patients with the definitive OGTT, a price that we pay to decrease the number of those patients with GDM who will be left undiagnosed.
→ The number of patients that will not be tested by the definitive OGTT is expected to decrease rather than increase (choice B). Patients who will not be tested by the OGTT are those who test negative with the screening OGCT. This includes the true negative and the false negative patients. Both of these categories will decrease. The increase in sensitivity would decrease the number of false negatives and the decrease in specificity would decrease the number of true negatives. Thus, fewer patients will not be tested by the definitive OGTTT.
→ The number of patients without the disease who are expected to test positive with the screening OGCT is expected to increase rather than decrease (choice C). Patients without the disease who test positive with screening test represent the false positive patients and their number is expected to increase due to the decrease of test specificity. The lower the specificity of a test, the higher is the number of false positive results.
→ The number of patients without the disease who are expected to test negative with the screening OGCT is expected to decrease rather than increase (choice E). Patients without the disease who test negative with screening test represent the true negative patients and their number is expected to decrease due to the decrease of test specificity. The lower the specificity of a test, the higher is the number of false positive results and the lower is the number of true negatives.
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