typically occurs during the first trimester and early portions of the second trimester. and extend past them. but usually resolves in 2nd trimester.

hCG levels (which peak at the same time as hyperemesis gravidarum symptoms) may be a cause for increased nausea.

| Risk factors | • Young women during their first pregnancy, not those of advanced (>35) maternal age • Hydatidiform mole • Multifetal gestation • History of hyperemesis gravidarum • History of migraines • History of motions sickness | | --- | --- | | Clinical features | • Severe, persistent vomiting • >5% loss of prepregnancy weight • Dehydration (dry pregnancy) • Orthostatic hypotension | | Laboratory abnormalities | • Ketonuria (suggests a more severe disease and indicates admission) • Hypochloremic metabolic alkalosis • Hypokalemia • Hemoconcentration • Elevated serum aminotransfersases | | Treatment | • Admission to hospital ( if severe ex ketonuria) • Antiemetics & intravenous fluids | | Prognosis | •When treated appropriately, there are no long-term adverse effects on the developing fetus |

<aside> 💡 Subtler clinical presentation → HG can be differentiated from typical nausea and vomiting of pregnancy by laboratory evaluation.

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<aside> 💡 Tobacco use protects against hyperemesis gravidarum, likely because it increases the metabolism of estrogen and thereby decreases serum estrogen levels.

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<aside> 💡 Elevated progesterone levels, which relax smooth muscle tone at the lower esophageal sphincter (ie, gastroesophageal reflux) and in the stomach (ie, delayed gastric emptying), can cause increased or persistent vomiting.

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Twin gestations are thought to be at an increased risk for hyperemesis gravidarum due to elevated hCG and progesterone concentrations from a larger placental volume.

• Labs rationale
• Management details

Although the pathophysiology of hyperemesis itself does not affect the fetus, mothers with hyperemesis gravidarum frequently have inadequate gestational weight gain. Low pre-pregnancy BMI and poor nutrient intake during pregnancy increase the risk of fetal growth restriction, low birth weight, and preterm delivery.

Hyperemesis gravidarum can present with transient hyperthyroidism (eg, thyrotoxicosis of hyperemesis) due to stimulation of the thyroid by elevated hCG levels. Thyroid studies are indicated only if there are overt signs of hyperthyroidism (eg, heat intolerance, enlarged thyroid or nodule).

Intrauterine growth restriction (IUGR) is a potential complication of severe HG. Other fetal complications of HG include low birth weight and preterm birth.

• Ddx
• EDUCATIONAL OBJECTIVES

Premature birth (Choice B) is birth that occurs before 37 weeks’ gestation, and its risk is increased by maternal diabetes, extremes of age, placenta previa or abruption, cervical insufficiency, multiple gestations, and maternal tobacco use. If insufficiently treated and unable to gain weight, this patient may be at risk for preterm labor, but this is less likely than no adverse effect if treated appropriately.