Fetal membranes help
The sac of fetal membranes that surround baby are essentially a zip-lock container that protects baby from lots of exposures.
The only entrance to this is through the placental blood vessels. Once the bag opens, all external germs have a chance to start moving up to baby. Prolonged rupture
(> 18hrs) starts to show an uptick of infection rate in babies during long labor
& may show need for c section.