A 33-year-old woman, gravida 3 para 0 aborta 2, at 28 weeks gestation comes to the office for a routine prenatal visit. The patient has had no contractions, vaginal bleeding, or leakage of fluid. Fetal movement is normal. Her pregnancy is complicated by type 1 diabetes mellitus that has become increasingly difficult to control with her insulin regimen. During the past month, most of the patient's postprandial blood glucose levels have been above 200 mg/dL. An anatomy ultrasound at 20 weeks gestation was normal; a follow-up growth ultrasound at 24 weeks gestation was at the 30th percentile. Blood pressure is 124/82 mm Hg and pulse is 88/min. Fundal height is 24 cm. Nonstress test is reactive and reassuring. Ultrasound reveals a cephalic fetus measuring at the 4th percentile for gestational age and an amniotic fluid index of 3 cm (normal: 5 cm). Which of the following is the best next step in management?

Question

A 33-year-old woman, gravida 3 para 0 aborta 2, at 28 weeks gestation comes to the office for a routine prenatal visit.  The patient has had no contractions, vaginal bleeding, or leakage of fluid.  Fetal movement is normal.  Her pregnancy is complicated by type 1 diabetes mellitus that has become increasingly difficult to control with her insulin regimen.  During the past month, most of the patient's postprandial blood glucose levels have been above 200 mg/dL.  An anatomy ultrasound at 20 weeks gestation was normal; a follow-up growth ultrasound at 24 weeks gestation was at the 30th percentile.  Blood pressure is 124/82 mm Hg and pulse is 88/min.  Fundal height is 24 cm.  Nonstress test is reactive and reassuring.  Ultrasound reveals a cephalic fetus measuring at the 4th percentile for gestational age and an amniotic fluid index of 3 cm (normal: >5 cm).  Which of the following is the best next step in management?

Quizplus · Accepted Answer

This patient has fetal growth restriction (FGR), an estimated fetal weight at <10th percentile for gestational age. FGR can be a complication of maternal vascular disease (eg, type 1 diabetes mellitus, chronic hypertension), which causes chronic placental vasoconstriction and ischemia with resultant uteroplacental insufficiency. As uteroplacental insufficiency worsens (ie, placental perfusion decreases), fetal oxygenation and nutrition also decrease. In response, fetal growth slows and blood is preferentially shunted from the fetal kidneys to the brain, causing FGR and associated oligohydramnios (ie, amniotic fluid index ≤5 cm), as seen in this patient. Patients with FGR have a high risk for intrauterine fetal demise and require an immediate umbilical artery Doppler ultrasound to assess placental perfusion (Choice D). This test measures intravascular flow and resistance in the umbilical artery, with increasing resistance indicating decreasing placental perfusion and worsening fetal hypoxia. These measurements are used to identify patients who require urgent delivery to minimize the risk of fetal demise. (Choice A) Cervical nucleic acid amplification testing for Neisseria gonorrhoeae and Chlamydia trachomatis is performed at the initial prenatal visit to prevent neonatal infection; however, neither organism causes FGR. In addition, repeat third-trimester testing is indicated only in high-risk patients (eg, age <25). (Choice B) Fetal aneuploidy (eg, trisomy 21) can cause FGR and oligohydramnios; however, presentation is typically at an earlier gestation. This patient's anatomy ultrasound at 20 weeks gestation was normal, making this diagnosis unlikely. (Choice C) Fetal fibronectin testing determines the risk of preterm delivery in patients with preterm contractions. This patient has had no contractions. Educational objective: Maternal vascular disease (eg, type 1 diabetes mellitus) can cause uteroplacental insufficiency, which typically presents with fetal growth restriction (FGR) and oligohydramnios. Due to the high risk of intrauterine fetal demise, patients with FGR require umbilical artery Doppler ultrasound to assess placental perfusion and the need for urgent delivery. References: ACOG practice bulletin no. 204: fetal growth restriction. (http://www.ncbi.nlm.nih.gov/pubmed/30681542) Doppler US in the evaluation of fetal growth and perinatal health. (http://www.ncbi.nlm.nih.gov/pubmed/29019748) Doppler assessment of the fetus with intrauterine growth restriction. (http://www.ncbi.nlm.nih.gov/pubmed/22464066)

A 33-Year-Old Woman, Gravida 3 Para 0 Aborta 2, at 28