Tuesday, October 17, 2017

Preventing Fetal Membrane Rupture

Given my history, I'm quite interested in pPROM, and what might be done to reduce the risk of pPROM. The obvious answer is to prevent bacteria from ascending into the uterus, which we're hoping to accomplish via the TAC and clearing out my chronic endometritis. Beyond that, though, I wanted to learn more about fetal membranes.

Below are a selection of research articles I found. I've mostly included those that found consistent results. This is why you won't see any studies on Vitamin C below, as C has mixed results with respect to FM rupture. The caveat: read these and make your own decision, and note that the researchers are often the same across these studies. I will say that if I"m ever pregnant again, I intend to stay on progesterone (P4) and take Alpha-lipoic acid.

Fetal Membrane structure (FMs):
Fetal membranes are composed of two layers, the chorion and the amnion. During pregnancy, a weak zone in the fetal membranes typically develops over the cervix. This is the spot that typically ruptures during a normal labor.

In various modeling and testing, the amnion is the most important component of FM with respect to strength. Thinner amnion and chorion are correlated to lower strength and greater risk of rupture.

See: Function and Failure of the Fetal Membranes, (2017) Verbruggen, et. al.

Etiology of FM rupture:
When looking at the weak zone that appears over the cervix in a healthy term pregnancy, researchers find remodeling of the collagen that makes up the FM. Inflammation/infection and bleeding/abruption both produce the same collagen remodeling effect, when modeled using TNF (for infection) and Thrombin (for abruption).

See: The physiology of fetal membrane weakening and rupture: Insights gained from the determination of physical properties revisited. (2016) Kumar, et. al.

Correlates with FM strength:

"The dietary supplement α-lipoic acid and progestogens (P4, MPA and 17α-hydroxyprogesterone) have been shown to inhibit both TNF and Thrombin induced FM weakening. The progestogens act at multiple points by inhibiting both GM-CSF production and GM-CSF action."

See: The physiology of fetal membrane weakening and rupture: Insights gained from the determination of physical properties revisited. (2016) Kumar, et. al.

Alpha-lipoic acid moderates the impact of both TNF and thrombin on FM. "Treatment of FM with 0.25 mM LA completely inhibited thrombin-induced FM weakening and MMP expression (all p < 0.001). Thrombin treatment of cultured FM induces mechanical weakening and increased MMP3 and 9. Treatment of FM with LA inhibits these thrombin-induced effects. We speculate LA may prove clinically useful in prevention of PPROM associated with abruption."

See: Alpha-lipoic acid inhibits thrombin-induced fetal membrane weakening in vitro. (2010), Moore, et. al.

"TNF and thrombin both weakened fetal membranes and elevated media GM-CSF levels on the choriodecidua side of the fetal membrane. Pretreatment with progesterone, MPA (medroxyprogesterone acetate), or HP (17α-hydroxyprogesterone) inhibited both TNF- and thrombin-induced fetal membrane weakening and also inhibited the induced increase in GM-CSF. GM-CSF decreased fetal membrane rupture strength by 68%, which was inhibited by progestogen pretreatment with a potency order: progesterone <MPA <HP"

See: Progesterone inhibits in vitro fetal membrane weakening. (2015). Kumar, et. al. 

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