HRT FOR UTERUS / NO OVARIES
While some women in Surgical Menopause have had both their uterus and ovaries removed (Hysterectomy), other women elect to keep their healthy uterus and remove their unhealthy ovaries (Oophorectomy). The reason for this being twofold: some women want to avoid having unnecessary surgery and uterus removal as it carries with it risks of damaging your urinary tract, bladder, rectum and other pelvic structures during surgery, which may require further surgical revision and also because women who have frozen their eggs or embryos prior to Oophorectomy still have the ability to carry their own children via In vitro fertilization (IVF).
Although both women who have had a Hysterectomy and an Oophorectomy may face challenges in selecting and balancing HRT, women who have kept their uterus face the added challenge of keeping their uterus healthy and their Endometrium (the mucous membrane than lines the uterus) thin. . Estrogen HRT stimulates the Endometrium to grow thicker, and taken without hormonal opposition this can lead to Uterine Cancer. The way most women keep their Endometrium healthy, thin, and avoid the risks of uterine cancer is through incorporating a Progesterone HRT or an Anti-estrogen such as bazedoxifene, either cyclically or combined continuously with their Estrogen HRT.
Hormone Cycling: Hormone Cycling is when you take your estrogen HRT alone, but every 3-4 months you take a cycle of Progesterone HRT along with your estrogen HRT, which causes your body to bleed and shed the built up Uterine Lining (Endometrium) and thus protect your uterus. Hormone Cycling can even be done once a month, as you would do if you were taking Birth Control Pills, though this method seems to be less common. One of the downsides of Hormone Cycling is that Cyclical bleeds can often cause your hormones to become un-balanced in the process, meaning that your body will have to re-adjust to HRT following each bleed. In addition, There is no substantiated benefit for the body to regularly bleed, so ultimately choosing this method is a personal choice.
Continuous Combined HRT: Continuous Combined HRT is when you continually take both Estrogen and Progesterone HRT. With this method the Progesterone balances out the Estrogen and keeps the uterine lining thin so the Endometirum does not have an opportunity to grow and doing a bleed to clean out your lining is no longer necessary. The downside to Continuous Combined HRT is that one must purposely take a high dose of Progesterone to achieve a thin uterine lining, thus inducing hormone imbalance in the body. Additionally, because of the high dose of progesterone required for this purpose, some women cannot or do not tolerate the effects of high Progesterone well.
The only exception to taking a high dose of progesterone is if a woman opts to have a hormonal IUD such as Mirena or Skyla inserted into her Uterus. An IUD releases progesterone directly into the uterus locally, keeping the lining thin, but it does not impact the systemic estrogen therefore bypassing many of the problems found in taking high doses of progesterone in other delivery forms such as Oral or Creams.