Hypertension In Pregnancy

Blood Volume Changes in Pregnancy

• Blood Volume Increase:

  • Increases during pregnancy alongside plasma and red cell volume.

  • Hemoglobin (H) and hematocrit (Hct) may decline as pregnancy progresses.

  • Mild dilutional anemia is common as plasma volume increases, diluting red blood cells.

• Anemia Considerations:

  • If hemoglobin (H) drops to 11 or below, iron supplementation is recommended to boost red blood cell production.

  • Normal anemia can occur in pregnancy, but levels below 11 require education and intervention.

• Importance of Treating Anemia:

  • Hemoglobin is crucial for oxygen transport, benefiting both mother and fetus.

  • Severe anemia increases risk of complications during delivery (e.g., hemorrhage).

  • Women with anemia are at higher risk for requiring blood transfusions postpartum.

Gestational Diabetes

• Testing for Gestational Diabetes:

  • Conducted in the second trimester via a one-hour glucose tolerance test (GTT).

  • Normal range for the one-hour test is less than 135 mg/dL; failures lead to a three-hour GTT.

• Three-Hour GTT Parameters:

  • Fasting: Less than 95 mg/dL.

  • One Hour: Less than 180 mg/dL.

  • Two Hour: Less than 155 mg/dL.

  • Three Hour: Less than 140 mg/dL.

  • Diagnosis of gestational diabetes requires failing one or more of these values.

• Gestational Diabetes Pathophysiology:

  • Insulin resistance occurs as a normal response during pregnancy.

  • Higher glucose levels can lead to larger-than-average (macrosomic) babies due to excess sugar intake.

  • Fetus produces insulin but does not receive maternal insulin; thus, post-birth hypoglycemia risk exists.

• Monitoring Neonates:

  • Newborns of diabetic mothers require blood sugar monitoring within the first 12-24 hours postpartum.

  • Normal blood sugar for infants is at least 40 mg/dL at birth; normal increases to at least 45 mg/dL afterwards.

Effects of Gestational Diabetes on Infants

• Surfactant Production:

  • Insulin reduces surfactant production, increasing respiratory distress risk in newborns.

  • Transient tachypnea of the newborn (TTN) may be common due to fluid retention.

• Polyhydramnios:

  • Associated with gestational diabetes due to increased urine production in the fetus.

  • Risk of umbilical cord prolapse during delivery due to excess fluid.

Hypertension in Pregnancy

• Types of Hypertension:

  • Chronic Hypertension: Present before pregnancy or diagnosed before 20 weeks gestation.

  • Gestational Hypertension: Diagnosed after 20 weeks, with blood pressure ≥ 140/90 on two occasions at least 6 hours apart.

• Preeclampsia:

  • Secretion of protein in urine (≥ 2+ on dipstick) and elevated blood pressure (≥ 140/90).

  • Can progress to severe preeclampsia with symptoms like headache, vision changes, and elevated liver enzymes.

• Magnesium Sulfate in Preeclampsia:

  • Used to prevent seizures in severe cases.

  • Monitor for signs of magnesium toxicity (e.g., decreased respiratory rate, decreased urine output).

  • Calcium gluconate as an antidote for magnesium toxicity.

Fetal Monitoring

• Non-Stress Test (NST):

  • Measures fetal heart rate and contractions to assess well-being.

  • Reactive NST requires at least two accelerations of fetal heart rate within a 20-minute monitoring:

    • 15 beats above baseline for 15 seconds in > 32-week fetuses.

• Biophysical Profile (BPP):

  • Combines NST with ultrasound evaluation for fetal well-being, scoring out of 10.

  • Assesses amniotic fluid volume, fetal movements, fetal tone, and breathing movements.

Nutritional Considerations During Pregnancy

• Maternal Weight Gain Recommendations:

  • Underweight (BMI < 18.5): Gain 28-40 pounds.

  • Normal weight (BMI 18.5-24.9): Gain 25-35 pounds.

  • Overweight (BMI 25-29.9): Gain 15-25 pounds.

  • Obese (BMI ≥ 30): Gain 11-20 pounds.

• Dietary Recommendations:

  • High protein intake reduces the risk for gestational hypertension and preeclampsia.

  • Limit caffeine intake to below 200 mg/day.

  • Focus on high-fiber foods and adequate hydration to combat constipation.