Why did the number of girls placed in orphanages increase during the one-child policy?

During the implementation of the one-child policy, the number of girls placed in orphanages increased primarily due to a deep-seated cultural preference for male children.12

Traditionally, particularly in rural areas, sons were highly valued because they inherited the family name and property, and they were expected to provide care for their elderly parents. When the government restricted most families to a single child, having a daughter became viewed as undesirable by many, leading to several tragic consequences.2

Beyond the increase in girls being placed in orphanages, this preference resulted in the abandonment of female infants, a rise in the abortion of female fetuses following the availability of ultrasound sex determination, and instances of infanticide. These actions collectively contributed to a significantly skewed sex ratio in China, with a notable surplus of males.123