1. Anatomical abnormalities
Uterine conditions such as polyps, scarring and/or internal fibroids which encroach upon the uterine cavity are often missed, and can be crucial.
In approximately 20% of cases, a dye x-ray (Hysterosalpingogram, or HSG) procedure – involving injection of radio-opaque dyes which x-rays can’t pass through – will obscure small endouterine surface lesions. And even very small lesions can affect implantation.
Many IVF doctors now prefer to use hysteroscopy and/or saline ultrasound (syn., hysterosonogram (HSN)/sonohysterogram) to assess the uterine cavity. A hysteroscopy allows for direct endoscopic visualization of the uterine cavity, while the saline ultrasound involves distention of the uterine cavity with an aqueous solution that allows the passage of sound waves, facilitating clear ultrasound imaging of the inner uterine wall.
An HSN/sonohysterogram is minimally invasive, and less expensive than a hysteroscopy or HSG.
2. Endometrial thickness
Way back in 1989, I published a study looking at the correlation between the thickness of the uterine lining (the endometrium), and the chances of embryo implantation in IVF patients. The study revealed that the ideal endometrial thickness at ovulation or egg retrieval is over 8 mm, and that thinner linings are connected to decreased embryo implantation rates.
Thinner uterine linings are mainly caused by:
- Damage to the basal endometrium (Sher Fertility Solutions examine the potential causes of this in our thin uterine lining deep-dive)
- Over-use of anti-estrogenic drugs, such as clomiphene citrate, without an adequate break between cycles
- Over-exposure of the uterine lining to ovarian male hormones (mainly testosterone)
- Reduced blood flow to the basal endometrium, often involving multiple uterine fibroids, and/or uterine adenomyosis
- Prolonged estrogen deprivation of the uterus, which might occur with premature ovarian failure (POF) or menopause, or result from the indiscriminate and prolonged administration of gonadotropin releasing hormone agonists (GnRHa), such as Lupron, Buserelin, Superfact, Decapeptyl
Viagra suppository, IVF and uterine blood flow
Decades ago, we announced the world’s first Viagra Baby, after reporting on the benefits of using vaginal Sildenafil (Viagra) with women experiencing implantation dysfunction due to thin endometrial lining.
Compounded Viagra administered vaginally (not orally) can improve uterine blood flow. This increases the amount of estrogen delivered to the endometrium, helping it to thicken.
The treatment comes with very few side effects, because the vaginally administered Viagra is so rapidly absorbed into the bloodstream. However, it’s not effective in all cases – a third of women who receive treatment don’t see any improvement, unfortunately. This is usually due to previous and permanent damage to the endometrium, leaving it unresponsive to estrogen.
3. Immunologic Implantation Dysfunction (IID)
Right now, practitioners generally connect unexplained and/or repeated IVF failure to poor embryo quality. And with this, the popular course of action is to change the protocol for ovarian stimulation, and/or gamete and embryo preparation.
But this is over-simplifying a highly complex area.
The implantation process starts six or seven days after fertilization. And at this time, specialized embryonic cells, which later form the placenta, engage in a “cross-talk” with the uterine lining and its immune cells, via hormone-like substances called cytokines. And it’s through this immunologic interplay, that the uterus can support an embryo’s successful growth. It’s the foundation for nutritional, hormonal and respiratory interchange between mother and baby, and central to healthy early pregnancy.
There’s an ever-growing realization, recognition and acceptance of the fact that uterine immunologic dysfunction can lead to immunologic implantation dysfunction (IID). And through this, its connection to “unexplained” infertility, IVF failure and recurrent pregnancy loss (RPL).
Join us next time with Dr Sher, for his expert take on immunologic problems, risk factors, diagnosis, and the connection to implantation failure.