What is the obstetric management for a 29-year-old woman, gravida 2 para 1, at 20 weeks gestation with a history of gestational diabetes mellitus (GDM), chronic hypertension requiring antihypertensive medications, and a previous cesarean delivery, presenting with normal fetal movement, no contractions, vaginal bleeding, or pelvic pain, and ultrasound findings of a single cephalic fetus at the 40th percentile for growth, cervical length of 4.4 cm, a posterior placenta extending over the cervix, and an amniotic fluid index of 18 cm, with a blood pressure of hypertension and a body mass index (BMI) of 38 kg/m², indicating obesity?

Differential Diagnosis

• Single most likely diagnosis
  • Gestational hypertension or chronic hypertension with superimposed gestational hypertension: The patient's history of chronic hypertension, current blood pressure of 144/96 mm Hg, and the presence of a fetus at the 40th percentile for growth suggest that her chronic hypertension may be contributing to her current condition, and the possibility of superimposed gestational hypertension cannot be ruled out.
• Other Likely diagnoses
  • Placenta previa: The ultrasound finding of a posterior placenta extending over the cervix is concerning for placenta previa, which can cause bleeding and other complications.
  • Fetal growth restriction: Although the fetus is currently at the 40th percentile for growth, the patient's history of gestational diabetes and chronic hypertension increases her risk for fetal growth restriction.
  • Preterm labor: The patient's history of preterm labor in her previous pregnancy increases her risk for recurrence.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Preeclampsia: Although the patient's blood pressure is elevated, she does not currently have proteinuria or other symptoms of preeclampsia. However, preeclampsia can develop rapidly and is a leading cause of maternal and fetal morbidity and mortality.
  • Placental abruption: The patient's history of chronic hypertension and previous cesarean delivery increases her risk for placental abruption, which can cause severe bleeding and fetal distress.
  • Uterine rupture: The patient's history of previous cesarean delivery increases her risk for uterine rupture, which can be life-threatening for both the mother and the fetus.
• Rare diagnoses
  • Chronic hypertension with superimposed preeclampsia and fetal growth restriction: This diagnosis is less likely but possible, given the patient's history and current presentation.
  • Intrauterine growth restriction due to uteroplacental insufficiency: This diagnosis is less likely but possible, given the patient's history of gestational diabetes and chronic hypertension.