A 27-year-old woman, gravida 1 para 0, at 28 weeks gestation comes to the office for a routine prenatal visit. Her initial prenatal laboratory results at 12 weeks gestation were as follows: The patient reports no vaginal bleeding, leakage of fluid, or contractions. There is good fetal movement. She has increasing urinary frequency and nocturia but no dysuria or hematuria. The patient has a history of tension headaches, which have become more frequent but resolve with acetaminophen. She has no other chronic medical conditions or previous surgeries. The patient works in a retirement home and reports leg swelling at the end of her shift. She is a vegetarian and takes a daily prenatal vitamin. She does not use tobacco, alcohol, or illicit drugs. Temperature is 37 C (98.6 F) , blood pressure is 128/76 mm Hg, and pulse is 86/min. BMI is 30 kg/m²; the patient has been gaining 0.5 kg (1.1 lb) a week during the pregnancy. The fetal heart rate is 152/min. Examination shows a uterus consistent with a 28-week gestation. There is trace lower extremity edema bilaterally. The patient has had no laboratory evaluations since her initial prenatal visit. Item 1 of 3
Which of the following is the most appropriate laboratory evaluation to perform at this visit?

Question

A 27-year-old woman, gravida 1 para 0, at 28 weeks gestation comes to the office for a routine prenatal visit. Her initial prenatal laboratory results at 12 weeks gestation were as follows:

The patient reports no vaginal bleeding, leakage of fluid, or contractions. There is good fetal movement. She has increasing urinary frequency and nocturia but no dysuria or hematuria. The patient has a history of tension headaches, which have become more frequent but resolve with acetaminophen. She has no other chronic medical conditions or previous surgeries. The patient works in a retirement home and reports leg swelling at the end of her shift. She is a vegetarian and takes a daily prenatal vitamin. She does not use tobacco, alcohol, or illicit drugs. Temperature is 37 C (98.6 F) , blood pressure is 128/76 mm Hg, and pulse is 86/min. BMI is 30 kg/m²; the patient has been gaining 0.5 kg (1.1 lb) a week during the pregnancy. The fetal heart rate is 152/min. Examination shows a uterus consistent with a 28-week gestation. There is trace lower extremity edema bilaterally. The patient has had no laboratory evaluations since her initial prenatal visit. Item 1 of 3
Which of the following is the most appropriate laboratory evaluation to perform at this visit?

Quizplus · Accepted Answer

Explanation: 11ec2b69_c03b_fcc5_8f63_d16fb854ea5e_MD0005_00 At 24-28 weeks gestation, all pregnant women should undergo screening for anemia with a hemoglobin/hematocrit or a complete blood count (which can be compared to results from the initial prenatal visit). Physiologic anemia occurs in most pregnancies secondary to an expanding plasma volume that is disproportionate to the increase in red blood cell mass. Iron requirements increase in pregnancy; treatment of physiologic anemia is with iron supplementation. Gestational diabetes mellitus screening is also performed at 24-28 weeks due to the rise in human placental lactogen, a hormone secreted by the placenta that increases fetal glucose supply by inducing maternal insulin resistance. Women with a positive 50-g 1-hour glucose challenge test undergo a subsequent confirmatory 100-g 3-hour glucose tolerance test prior to the diagnosis of gestational diabetes mellitus. In addition, Rh(D)-negative women should undergo antibody screening and receive an anti-D immune globulin injection. (Choice A) A 24-hour urine collection for protein is used in the evaluation of preeclampsia. Although this patient has headaches and edema often associated with preeclampsia, she is not hypertensive, so this diagnosis is excluded. (Choice C) This patient requires screening for anemia, gestational diabetes, and, if she is Rh(D)-negative, antibody screening. (Choice D) Thyroid testing is performed in patients with symptoms of hypothyroidism or hyperthyroidism or with known thyroid disease as pregnancy alters thyroxine-binding globulin, free T4, and T3 levels. Universal screening for thyroid dysfunction in asymptomatic pregnant women is not recommended. (Choice E) A urine culture is often sent in early pregnancy to screen for asymptomatic bacteriuria (especially due to group B Streptococcus), as was done in this patient. Subsequently, a urine culture should be sent only when cystitis or pyelonephritis is suspected. This patient has urinary frequency and nocturia, both common symptoms of pregnancy unrelated to urinary tract infection in the absence of dysuria and hematuria. Educational objective: All pregnant women should be screened for anemia and gestational diabetes mellitus at 24-28 weeks gestation secondary to physiologic changes occurring at this time. Testing is performed due to expanding red blood cell mass and relative insulin resistance from secretion of human placental lactogen. References: Update on prenatal care. (http://www.ncbi.nlm.nih.gov/pubmed/24506122) ACOG practice bulletin no. 95: anemia in pregnancy. (http://www.ncbi.nlm.nih.gov/pubmed/18591330) Practice bulletin no. 137: gestational diabetes mellitus. (http://www.ncbi.nlm.nih.gov/pubmed/23969827)

A 27-Year-Old Woman, Gravida 1 Para 0, at 28 Weeks