There are so many concubines of Emperor Xianfeng, why is there only one child?
In the first aspect, Xianfeng was born weak. At that time, Quanfei and ChristianRandPhillips were pregnant. After the death of Yi Wei, the eldest son, if one of them gave birth to a child, it was the eldest son. Since ancient times, it always takes a long time to be a saint. Therefore, Quanfei took a bet on oxytocin and gave birth to Xianfeng in advance. Being born as the eldest son paved the way for Xianfeng's later life, but at the cost of Xianfeng's premature constitution.
Second, Xianfeng's acquired habits are not good. Legend has it that Xianfeng is lewd and loves to smoke and drink. At that time, smoking opium would reduce his physical fitness. Xianfeng's own poor health is even worse. In fact, it makes sense for modern eugenics to ban smoking. If Xianfeng can fight for breath the day after tomorrow, practice martial arts diligently and exercise more, maybe his physique will be stronger. Unfortunately, Xianfeng himself does not cherish it.
Third, the court struggle made it difficult for future generations to survive. It is not right to say that Cixi killed her. Xianfeng actually had three children, one of whom died young, probably a victim of court battles. Another daughter left at the age of 22. Comrades can't live past twenty. The child who may be born is in poor health. It may also be caused by palace fighting.
The above is my view on this matter. Xianfeng is a typical example of not deliberately running its own business because of internal and external troubles. Otherwise, it would not be the turn of the blue noble to return to the palace to be the Empress Dowager Cixi, which directly put Cixi in power and accelerated the demise of the Qing Dynasty.