A 28-year-old woman, gravida 1 para 0, comes to the office for an initial prenatal visit. The patient has had no vaginal bleeding or abdominal pain and has not yet felt fetal movement. Menarche occurred at age 13. She sometimes has heavy menstrual bleeding with passage of clots, and other times she skips her menses. The patient's estimated gestational age based on her last menstrual period is 16 weeks. She has type 1 diabetes mellitus that is controlled with insulin. She smokes a pack of cigarettes daily. As part of her prenatal laboratory screening, a second-trimester maternal serum quadruple screen is performed and reveals an elevated alpha-fetoprotein level. Which of the following is the most likely etiology of this patient's abnormal screening result?

Question

A 28-year-old woman, gravida 1 para 0, comes to the office for an initial prenatal visit.  The patient has had no vaginal bleeding or abdominal pain and has not yet felt fetal movement.  Menarche occurred at age 13.  She sometimes has heavy menstrual bleeding with passage of clots, and other times she skips her menses.  The patient's estimated gestational age based on her last menstrual period is 16 weeks.  She has type 1 diabetes mellitus that is controlled with insulin.  She smokes a pack of cigarettes daily.  As part of her prenatal laboratory screening, a second-trimester maternal serum quadruple screen is performed and reveals an elevated alpha-fetoprotein level.  Which of the following is the most likely etiology of this patient's abnormal screening result?

Quizplus · Accepted Answer

Eductional Objective: The maternal serum quadruple screen assesses for risk of congenital defects and fetal aneuploidy and includes measurement of alpha-fetoprotein levels, which are dependent on gestational age.  An abnormal alpha-fetoprotein level is most commonly due to a dating error (eg, inaccurate gestational age).

A 28-Year-Old Woman, Gravida 1 Para 0, Comes to the Office