During childbirth, larger babies have more difficulty passing through the birth canal.

在分娩时，较大的婴儿更难通过产道。

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Patients can be infected by the mother's birth canal or amniotic fluid and.

小患者可以通过母亲的产道或羊水而被感染。

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Babies get their first exposure to bacteria that colonise their guts as they travel down the birth canal.

当婴儿们从产道出生，细菌占据了他们的肠道时，他们就第一次暴露于细菌之下。

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When a baby's head is stuck in the birth canal for an extended period of time, it cuts off the blood supply to the woman's surrounding organs.

VOA: special.2010.08.09

Access to a Caesarean section to relieve the pressure of obstructed labor is the most common way of preventing an unborn child from pressing so tightly in the birth canal that it cuts off blood flow to surrounding tissue.

VOA: standard.2009.12.23

When they go through the birth canal, they get exposed to the entire bacteria population of their mother's vaginal and GI microbiomes.

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One might conclude that this trait evolved to ease their passage through a narrow birth canal, but it seems to result from the way vertebrate skeletons develop.

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In addition, young mothers face terrible threats to their health such as fistula -- a hole in the birth canal caused by prolonged labor without prompt medical intervention.

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