Which features are more likely to occur in a male fetus?

Pyloric stenosis is a condition that is indeed more commonly observed in male infants than in females, with a male-to-female ratio reported to be as high as 4:1. This condition involves the narrowing of the pylorus, which is the opening between the stomach and the small intestine, and leads to projectile vomiting, dehydration, and metabolic imbalances.

Factors contributing to the increased incidence of pyloric stenosis in males could be genetic predispositions or hormonal influences, although the exact cause remains unclear.

In contrast, the other conditions listed (anencephaly, congenital hip dislocation, and isolated congenital pulmonary issues) do not exhibit the same strong male predominance. For example, anencephaly occurs with a more balanced sex ratio, while congenital hip dislocation is somewhat more common in females. Isolated congenital pulmonary conditions can also occur in both sexes with no notable bias. Understanding these differences is essential for genetic counseling and management, as they provide insights into the risk factors and prevalence associated with various congenital disorders.