Studies (or why Googling is bad for you)

I have been a busy Googler. It seems the few years since I started my IF journey, there have been a few more studies now that have started to focus on the impact of radiation and chemo on fertility, and some even specifically look at the impact pediatric radiation has on fertility and uterine function. So I thought I would share the information I have collected so far. So here is what I know so far. And let me warn you, this will be depressing (for me).

Problem No. 1: POI (or POF) is an almost certainty after total body irradiation (TBI) or pelvic irradiation. I am almost certain I had both. Although my records from the bone marrow transplant are not clear on this point, and do not show exactly how much radiation I received. I plan on asking my parents if they recall the actual treatment regimen I was on and discuss this at my next RE appointment.

Ok, so nothing new here. We knew my ovaries were dunzo. So we will overcome the lack of viable eggs with a donor egg from my sister. So far so good.

Problem No. 2: “The lack of oocytes may be compensated for by oocyte donation but these patients also seem to have a uterine factor” Doh!

A paper published in 2000 in the Oxford Journals studied three women who had overcome childhood cancer with a bone marrow transplant which included TBI. Only two out of the three had a successful pregnancy, and only one of those resulted in a live birth.

Essentially it boils down to what age you had TBI and the size of the uterus at the time. For those who were exposed to TBI pre-puberty the uterus remains relatively small. While after puberty the size of the uterus is more normal and seems to have a better chance of carrying a fetus to term.

“An adult size uterus measures about 7.5 cm in length, 5 cm in breadth at its upper part, and about 2.5 cm in thickness”. A further paper on Biomed Research International in 2014 looked at the impact of uterine radiation on subsequent fertility.

“The irradiated endometrium is atrophic, with thickened and smaller blood vessels. Hence, radiation may reduce reproductive potential by damaging the myometrium, the endometrium, and the uterine vasculature. The uterine volume in women with premature ovarian failure (POF) is often reduced, with poor blood flow and a thin endometrium. Radiation exposure may induce further damage, resulting in a reduced uterine volume and decreased elasticity of uterine musculature.”

Quick health class lesson: During puberty, the uterus continues to grow until the age of about 20. So at age 12, I was in the very early stages of puberty, and if I remember correctly I had just stated to develop outwards signs of puberty. Tanner stage 2 or 3 at the time of transplant. I did continue to develop externally after the transplant, but the question remains how did this impact my uterus?

Time for a picture break:

uterus

Illu_cervix

“Direct high dose radiation (>25 Gy) in children commonly leads to irreversible damage to both vasculature and muscular function of the uterus.” Darn.

Lets assume I received a decent amount of radiation. Maybe not >25Gy, but maybe half that. It still looks rather bleak. The paper also refers to another study where women with spontaneous POI were compared against women with radiation related POI. It was noted that the women with radiation related POI had a significantly smaller uteri than the other women (4.1 cm v. 7.3 cm respectively of mean uterine length). Additionally 70% of the women who had irradiated uteri had almost no detectable blood flow to the uterine arteries, compared to the other women who retained normal blood flow.

“[Hormone] Replacement therapy of 3 months or more increases uterine volume, increases midluteal endometrial thickness, and restores uterine vascular supply in women exposed to TBI in childhood or adolescence.” But what it does not do is fix any issues with uterine size. Also a longer period of HRT does not seem to improve the results beyond what the first 3 months could achieve. So there does seem to be a limit in how much HRT can improve some of the issues caused by radiation.

So what is my uterine size and how does this compare to the average adult female uterus? Another question for my RE follow up next month.

Problem No. 3: Those pesky 37 weeks of gestation. So even if we were to find an embryo, and sufficiently boost blood flow to build an endometrial lining for it to stick, there is a high likelihood of very serious complications during pregnancy due to the damage done to the uterus. These include:

  • Spontaneous abortion/Miscarriage/Stillbirth – in many cases women would experience this loss in the second trimester, around the 17 to 20 week mark.
  • Preterm delivery
  • Low birth weights
  • Premature labour
  • Placental hemorrhage
  • Preeclampsia

The complications seem to be more common in those that get pregnant with ART. And the chances are significantly higher like in the third to a half times more likely range.

So there it is. I not only have to focus on building a lining, but also, even if we are successful at implanting an embryo, the chances that I will see a baby born are limited at best. Almost feels like it isn’t worth the effort.

Sigh.

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