I recently attended a beautiful, straightforward birth center birth. SROM, onset of contractions shortly after ROM. No varying fetal heart tones, high leak of amniotic fluid until mom started feeling an overwhelming urge to push, when the forebag released. After the placenta was birthed (20 minutes later, presenting Dirty Duncan). We found this:
"Marginal (Battledore) insertion. The cord implants along the placental margin rather than central to the body of the placenta"...And what might have gone wrong in a more 'managed' birth (i.e. what had a high probability of happening in a hospital setting, or with a more 'managing' midwife)?
"Velementous insertions are not implanted in the body of the placenta but rather traverse the extraplacental membranes"...
"Furcate insertion (insertio funiculi furcata), - the cord vessels lose their protective coating of Warton's Jelly prior to inserting into the body of the placenta." - Patricia Edmonds, The Placenta: A Guide To Examination
Battedore Insertion... "the cord is less mobile and therefore more prone to compromise. Stresses that may cause complications include the use of labor stimulating drugs and herbs. Forced third stage of the birth i.e. cord traction. The vessels are not exposed, being protected by membranes and surrounded by Warton's Jelly."AROM, induction, labor stimulation, and active management of 3rd stage is much less likely to occur in out-of-hospital births. Additionally, active management of 3rd stage labor could easily have torn the cord and/or the velamentously inserted vessels prior to complete separation and/or complete delivery of the placenta - resulting in either a hemorrhage or necessitate a manual extraction of the placenta and/or D&C.
Velamentous Insertion... is "definitely associated with increased risks for the baby due to hemorrhage as the unprotected vessels are at much greater risk of thrombosis and tearing. They are also at greater risk for compression. They are more likely to occur with "advanced" maternal age, diabetes mellitus, smoking and SUA (single umbilical artery)" [none of which this mama had]. Additionally, depending on implantation site, AROM has a higher chance of nicking/tearing through one of the vessels, causing massive hemorrhage. AROM is less likely to occur in out-of-hospital birth.
Furcate insertion (insertio funiculi furcata)... "These exposed vessels are prone to thrombosis and injury".
Birth works - if we trust mom and baby, their innate knowledge of what they need, their intuition and nature's design, birth works in nearly all circumstances. And for the rest, thank God for hospitals and skilled surgeons and physicians.