A 32 week pregnant female diagnosed of having polyhydramnios. The fetus may have the following malformations, EXCEPT:
**Core Concept**
Polyhydramnios refers to an excessive accumulation of amniotic fluid, often associated with fetal anomalies or maternal diabetes. The underlying pathophysiology involves impaired fetal swallowing and/or abnormal fetal urination, leading to an imbalance in amniotic fluid dynamics.
**Why the Correct Answer is Right**
Polyhydramnios is commonly associated with congenital anomalies of the gastrointestinal tract, such as esophageal atresia, duodenal atresia, and gastroschisis. These conditions impair the fetus's ability to swallow and absorb amniotic fluid, resulting in its accumulation. In contrast, most cardiac malformations do not directly impair fetal swallowing or urination.
**Why Each Wrong Option is Incorrect**
**Option A:** Congenital diaphragmatic hernia may not directly impair fetal swallowing or urination, but it can lead to polyhydramnios due to impaired lung development and subsequent respiratory distress postnatally. However, it is not as directly related to polyhydramnios as gastrointestinal tract anomalies.
**Option B:** Esophageal atresia is a classic cause of polyhydramnios, as the fetus is unable to swallow amniotic fluid.
**Option C:** Gastroschisis is another condition that can lead to polyhydramnios due to impaired fetal swallowing.
**Clinical Pearl / High-Yield Fact**
Polyhydramnios is a significant risk factor for preterm labor, fetal distress, and neonatal respiratory complications. It is essential to perform thorough fetal anomaly screening and monitor amniotic fluid levels closely in affected pregnancies.
**Correct Answer: C. Gastroschisis is actually associated with oligohydramnios, not polyhydramnios.**