Adenomyosis

Adenomyosis is the growth of tissue similar to the uterine lining into the myometrium, the muscle wall of the uterus. This tissue contains glands and supporting cells (stroma). The uterus may enlarge. The junctional zone, the inner layer of the myometrium, may thicken. Adenomyosis can cause heavy menstrual bleeding and painful periods (dysmenorrhea). It can also cause pain during intercourse (dyspareunia) and bleeding between periods. Some women have no symptoms, and the condition is discovered by chance.¹²

Adenomyosis has two main types: diffuse and focal. The two types differ in their features and in their treatment.¹²³

Diffuse adenomyosis is the more widely recognized type. The tissue spreads throughout the muscle wall. The uterus becomes enlarged and soft (boggy). This type is more common in women who have had several pregnancies. A firm diagnosis requires a microscope examination of uterine tissue. In the past, that tissue usually came from a hysterectomy, the surgical removal of the uterus. Today, clinicians usually diagnose diffuse adenomyosis from symptoms together with imaging. A thickened junctional zone on imaging strongly suggests the condition, but it cannot confirm it.²³ Diffuse adenomyosis does not necessarily reduce fertility. It is often found in women who have already had children, and many conceive without difficulty. Diffuse disease is more strongly linked to heavy bleeding and pain than to infertility. One meta-analysis, a combined analysis of many studies, found that the type alone, focal or diffuse, did not significantly change pregnancy outcomes.⁴

Focal adenomyosis has a different appearance. It includes adenomyomas, which are discrete masses that can resemble fibroids on imaging. Focal changes can also form within a cesarean scar. This finding is distinct from an isthmocele, a defect where the cesarean scar did not heal completely. Ultrasound works somewhat better for focal disease than for diffuse disease. It still cannot confirm the diagnosis.¹² Focal disease also follows a different treatment path. A surgeon can remove the lesion and preserve the function of the uterus. For women who want to conceive, excision of focal disease is the restorative surgical path that preserves the uterus.¹³ When diffuse disease is severe and other care has failed, hysterectomy may be the only lasting treatment.²

Some studies link adenomyosis to poorer pregnancy outcomes. One meta-analysis found that women with adenomyosis had lower odds of clinical pregnancy (odds ratio 0.69). They also had more than twice the odds of miscarriage (odds ratio 2.17) compared with women without the condition.¹ These women came from assisted-reproduction programs. In that setting, the disease is often more severe and other conditions are common. The figures show an association. They do not predict the outcome for any individual woman. They also do not show that diffuse adenomyosis, by itself, reduces fertility.

Improved ultrasound now detects adenomyosis far more often. Published estimates of its prevalence (how common it is) range from 5% to 70%. This wide range reflects how much diagnostic criteria and imaging methods vary.⁴ When imaging attributes infertility to the uterus too quickly, couples may be steered toward care that leaves the actual disease in place. IVF is not a treatment for adenomyosis. It does not remove or shrink the disease. IVF tries to start a pregnancy in a uterus that still carries the disease. For focal adenomyosis, surgical removal of the lesion treats the disease itself. For diffuse disease, when a woman wants to keep her uterus and conceive, care focuses first on controlling heavy bleeding and pain.

Restorative reproductive medicine regards adenomyosis as a distinct condition. Each type requires its own evaluation. Adenomyosis is one finding to weigh within a full search for the cause of infertility. NaProTechnology-trained clinicians assess adenomyosis in the context of the whole cycle. Their assessment includes cycle charting and hormone patterns in the luteal phase, the phase of the cycle after ovulation. Heavy bleeding and low progesterone patterns often occur together. Neither is simply the cause of the other. Suppressive medications mask symptoms without addressing disease progression. The restorative goal is to find and treat the actual lesion behind the symptoms.