A 24-year-old woman, gravida 1 para 0, at 28 weeks gestation comes to the office for a routine prenatal visit. She feels well and has had no vaginal bleeding, contractions, or leakage of fluid. Fetal movement is normal. The patient has no chronic medical conditions and her pregnancy has been uncomplicated. She previously had heavy menstrual periods that were managed with oral contraceptives. Blood pressure is 126/84 mm Hg and pulse is 78/min. Fundal height and fetal heart tones are normal. Today's third-trimester complete blood count is as follows: Coagulation studies and peripheral smear are within normal limits. The patient's first-trimester platelet count was 160,000/mm³. Urine dipstick today is negative for protein. Which of the following is the most likely cause of this patient's thrombocytopenia?

Question

Quizplus · Accepted Answer

Eductional Objective: Gestational thrombocytopenia is common in the third trimester and is typically mild, asymptomatic, and not associated with other laboratory abnormalities.  It occurs due to hemodilution (ie, maternal plasma volume expansion) and increased sequestration/consumption of platelets in the placenta.

A 24-Year-Old Woman, Gravida 1 Para 0, at 28 Weeks