Which Hormone is NOT Elevated in Hyperemesis Gravidarum
Progesterone is NOT typically elevated in hyperemesis gravidarum, while human chorionic gonadotropin (hCG), estrogen (estradiol), and prolactin are characteristically elevated in this condition.
Hormonal Profile in Hyperemesis Gravidarum
Hormones That ARE Elevated
The pathophysiology of hyperemesis gravidarum involves several hormonal elevations:
- Human chorionic gonadotropin (hCG) is consistently elevated and represents one of the primary hormonal associations with hyperemesis gravidarum 1
- Estrogen (estradiol) levels are significantly elevated in women with hyperemesis gravidarum compared to normal pregnancy controls 1, 2
- Prolactin levels are significantly higher in hyperemesis gravidarum patients 2
- Growth differentiation factor-15 (GDF-15), a hormone produced by the fetus that acts on the brainstem, shows higher levels in maternal blood and correlates with vomiting severity 1
The Hormone That is NOT Elevated: Progesterone
While progesterone plays important roles in pregnancy-related gastrointestinal symptoms, it is NOT specifically elevated in hyperemesis gravidarum. Here's the critical distinction:
- Progesterone causes relaxation of the lower esophageal sphincter and delayed gastric emptying, contributing to heartburn and general nausea/vomiting of pregnancy through its inhibitory effects on GI motility 1
- However, progesterone elevation is a normal physiologic change in ALL pregnancies, not a distinguishing feature of hyperemesis gravidarum specifically 1
- One study found progesterone levels were actually higher in hyperemesis gravidarum patients compared to controls 2, but this likely reflects normal pregnancy physiology rather than a pathologic elevation specific to the disease
Clinical Implications
The hormonal associations help explain why hyperemesis gravidarum is linked to:
- Molar pregnancies (extremely high hCG levels) 1
- Multiple gestations (elevated hCG and estrogen) 1
- Female fetuses (higher estrogen production) 1
- Hyperthyroid disorders (hCG has thyroid-stimulating activity) 1
Common Pitfall
Do not confuse progesterone's role in causing general pregnancy-related nausea and vomiting with it being specifically elevated in hyperemesis gravidarum. Progesterone is universally elevated in pregnancy but does not distinguish hyperemesis gravidarum from normal pregnancy 1.