What are the next steps for a 28-year-old pregnant female in her third trimester with a due date in May, who had a recent blood pressure (BP) reading of 143/90 one week ago, but currently has a BP of 100/71, and is in contact with her healthcare provider and undergoing necessary laboratory tests?

Management of Recent Elevated Blood Pressure in Third Trimester Pregnancy

Given the current normal blood pressure (100/71 mmHg) and single elevated reading one week ago (143/90 mmHg), this patient requires close outpatient monitoring with specific laboratory evaluation to screen for preeclampsia, but does not need immediate hospitalization or urgent treatment at this time. 1

Immediate Next Steps

Laboratory Evaluation Required

The patient needs comprehensive laboratory testing to evaluate for preeclampsia, including: 1, 2

• Complete blood count (to assess platelet count for thrombocytopenia)
• Liver enzymes (AST, ALT, LDH to detect hepatic involvement)
• Serum creatinine and uric acid (to assess renal function)
• Urine protein assessment via spot protein:creatinine ratio or 24-hour urine collection 2

A urine dipstick showing ≥1+ proteinuria should be followed immediately with albumin-to-creatinine ratio (ACR) in a spot urine sample; ACR <30 mg/mmol reliably excludes significant proteinuria. 2

Blood Pressure Monitoring Protocol

The single reading of 143/90 mmHg requires repeat confirmation and ongoing surveillance: 2

• Repeat blood pressure measurements should be obtained using a validated device for pregnancy 2
• The measurement should be repeated with proper technique (the initial reading may have been falsely elevated due to the arm injury) 1
• Home blood pressure monitoring or ambulatory blood pressure monitoring using pregnancy-validated devices is reasonable for ongoing assessment 2

Risk Stratification

Current Clinical Status

This patient's blood pressure of 143/90 mmHg falls into the non-severe hypertension range (systolic 140-159 mmHg or diastolic 90-109 mmHg). 3, 4 The current reading of 100/71 mmHg is normal, suggesting the elevated reading may have been transient or related to the arm injury.

When to Escalate Care

Same-day hospital assessment is mandatory if: 1, 2

• Blood pressure reaches ≥160/110 mmHg on repeat measurement (15 minutes apart) 2, 1
• Development of symptoms including severe headache, visual disturbances, right upper quadrant or epigastric pain, nausea/vomiting, or decreased urine output 2
• Laboratory abnormalities suggesting preeclampsia (thrombocytopenia, elevated liver enzymes, rising creatinine) 2, 1

Treatment Thresholds

If Persistent Non-Severe Hypertension Develops

Antihypertensive medication should be initiated if blood pressure persistently measures ≥140/90 mmHg on multiple occasions, particularly if: 2, 3

• Gestational hypertension with or without proteinuria develops 2, 3
• Any evidence of preeclampsia emerges 2
• The patient has chronic hypertension with superimposed gestational hypertension 2, 4

The most recent guidelines from the American College of Obstetricians and Gynecologists, based on the CHAP trial, support treating chronic hypertension to a goal BP <140/90 mmHg to reduce preeclampsia risk without compromising fetal growth. 2

First-line oral antihypertensive agents for non-urgent treatment include: 3, 4, 5

• Methyldopa (traditional first choice) 6, 4
• Labetalol (comparable efficacy to methyldopa) 3, 5
• Long-acting nifedipine (calcium channel blocker) 3, 5

If Severe Hypertension Develops (≥160/110 mmHg)

This constitutes a hypertensive emergency requiring urgent treatment within 30-60 minutes to prevent maternal stroke and intracerebral hemorrhage. 2, 1 First-line agents include: 2, 1

• Oral immediate-release nifedipine
• Intravenous labetalol
• Intravenous hydralazine

Delivery Planning

Timing of Delivery

At 37 weeks gestation or beyond, delivery is recommended for any confirmed hypertensive disorder of pregnancy rather than expectant management. 2, 1 The optimal delivery time for gestational hypertension without preeclampsia features is 38-39 weeks. 1

Earlier delivery (<37 weeks) is indicated if: 2, 1

• Inability to control blood pressure with ≥3 antihypertensive classes
• Progressive thrombocytopenia or deteriorating liver/renal function
• Severe persistent symptoms (headache, visual changes)
• Placental abruption
• Non-reassuring fetal status 2, 1

Critical Pitfalls to Avoid

• Do not dismiss a single elevated reading – it may represent the onset of gestational hypertension or preeclampsia, which can progress rapidly 2
• Do not delay laboratory evaluation – preeclampsia can develop without severe hypertension, and organ dysfunction may occur at relatively mild BP elevations 2
• Ensure proper BP measurement technique – the arm injury may have affected the initial reading, but this must be verified with repeat measurements using proper technique 2
• Do not wait for proteinuria to diagnose preeclampsia – current definitions include preeclampsia with evidence of other maternal organ dysfunction even without proteinuria 2

Ongoing Surveillance Until Delivery

• Weekly blood pressure checks minimally; more frequent if any elevation persists 2
• Repeat laboratory testing if hypertension persists or symptoms develop 2, 1
• Patient education on preeclampsia warning signs requiring immediate evaluation 2
• Fetal surveillance with assessment of fetal growth and well-being 2, 1