Common Discomforts in Pregnancy Caused by Increased Progesterone Levels
The correct answer is A. Constipation, as increased progesterone levels directly slow gastrointestinal motility throughout pregnancy.
Progesterone-Mediated Gastrointestinal Effects
Constipation is the primary discomfort directly caused by elevated progesterone levels. Progesterone slows GI motility throughout the gastrointestinal tract, affecting 20-40% of pregnant women 1. The mechanism is well-established: increased progesterone levels reduce intestinal transit time and bowel movement frequency 1.
Why Constipation is Progesterone-Related
- Direct hormonal mechanism: Progesterone acts as a smooth muscle relaxant, decreasing peristalsis and prolonging transit times throughout the intestinal tract 1
- Onset timing: Effects begin in the first trimester when progesterone levels start rising and persist throughout pregnancy 1
- Physiologic basis: The American Gastroenterological Association (AGA) 2024 guidelines explicitly state that "increased levels of progesterone can slow GI motility" as the primary hormonal cause of pregnancy-related constipation 1
Why Other Options Are Not Primarily Progesterone-Related
B. Bleeding Gums
- Not progesterone-mediated: Bleeding gums result from increased blood volume, vascular changes, and altered immune response to oral bacteria during pregnancy
- No evidence links progesterone directly to gingival bleeding in the provided guidelines
C. Lower Back Pain
- Mechanical, not hormonal: Lower back pain primarily results from the physical weight of the gravid uterus, postural changes, and relaxin effects on ligaments
- While progesterone has some musculoskeletal effects, it is not the primary cause of lower back pain
D. Nasal Stuffiness
- Vascular, not progesterone-specific: Nasal congestion results from increased blood volume and vascular engorgement
- The American Heart Association notes that "upper airway edema and friability occur as a result of hormonal effects" 1, but this is a general hormonal effect, not specifically progesterone-mediated
Additional Progesterone Effects on the GI Tract
Beyond constipation, progesterone causes other gastrointestinal changes:
- Gastroesophageal reflux: Progesterone relaxes the lower esophageal sphincter and prolongs gastric emptying, predisposing to reflux and aspiration risk in the second and third trimesters 1
- Increased ventilation: Elevated progesterone increases minute ventilation by 20-40% above baseline by term, though this is a respiratory rather than discomfort effect 1
Clinical Implications
The AGA 2024 guidelines recommend managing progesterone-induced constipation with 1:
- Dietary fiber intake increased to approximately 30 g/day
- Adequate fluid consumption
- Bulk-forming agents (psyllium, methylcellulose) as first-line therapy
- Osmotic laxatives (polyethylene glycol, lactulose) as safe alternatives
- Avoidance of stimulant laxatives due to conflicting safety data