What is the cause of increased premenstrual syndrome (PMS) symptoms, including mood swings, in a 41-year-old female with a Mirena (levonorgestrel-releasing intrauterine device (IUD)) over the past 6 months?

Increased PMS Symptoms in a 41-Year-Old with Mirena IUD

The most likely cause of worsening PMS symptoms including mood swings over the past 6 months in this 41-year-old woman with a Mirena IUD is perimenopause-related hormonal fluctuations, though progestin-induced mood effects from the levonorgestrel IUD itself cannot be excluded and warrant evaluation.

Understanding the Clinical Context

At age 41, this patient is entering the typical age range for perimenopause (typically begins in the mid-40s but can start earlier), which causes erratic ovarian hormone production and can trigger or worsen PMS symptoms. 1, 2 The timing of symptom onset after 6 months suggests this is not related to initial IUD adjustment, as bleeding irregularities and hormonal side effects from the Mirena typically occur in the first 3-6 months and then improve. 3, 4, 5

Primary Differential Diagnosis

Perimenopause as the Leading Cause

• Women in their early 40s commonly experience increased PMS symptoms due to fluctuating estrogen and progesterone levels during irregular ovulatory cycles, even with a levonorgestrel IUD in place. 1, 2
• PMS develops when predisposed individuals are exposed to progesterone after ovulation, and the Mirena does not consistently suppress ovulation—it primarily works through local endometrial effects and cervical mucus thickening. 6
• The cyclical nature of mood symptoms tied to the luteal phase strongly suggests ongoing ovulation with perimenopause-related hormonal instability. 1, 2

Progestin-Induced Mood Effects

• Progestin-only contraceptive methods, including the levonorgestrel IUD, have documented potential to negatively affect mood symptoms in women with or without baseline mood disorders, including those with PMS/PMDD. 6
• Progesterone metabolites, particularly allopregnanolone, are neuroactive and can induce adverse mood effects through the GABA system in the brain. 2
• However, if the IUD has been in place longer than 6 months and symptoms only recently worsened, the IUD itself is less likely to be the primary culprit. 3, 4

Essential Diagnostic Evaluation

Before attributing symptoms to either cause, rule out the following:

• Verify IUD position through speculum examination to ensure strings are visible and the device hasn't displaced, as malposition can cause hormonal irregularities. 7, 4, 5
• Obtain pregnancy test (urine or serum) to exclude pregnancy, including ectopic pregnancy, which can present with mood changes and irregular bleeding. 7, 4
• Screen for sexually transmitted infections (gonorrhea and chlamydia) if risk factors present, as pelvic inflammatory disease can manifest with systemic symptoms. 7, 4
• Assess for new uterine pathology through pelvic ultrasound if clinically indicated, particularly if bleeding patterns have changed alongside mood symptoms. 7, 4

Management Algorithm

Step 1: Confirm Diagnosis Through Prospective Tracking

• Have the patient complete the Daily Record of Severity of Problems (DRSP) for at least two consecutive menstrual cycles to confirm the luteal-phase timing of symptoms and distinguish true PMS/PMDD from other mood disorders. 1
• This documentation is essential because symptoms must occur specifically during the luteal phase and resolve within a few days of menstruation to meet PMS criteria. 1

Step 2: First-Line Treatment Options

If PMS/PMDD is confirmed and the IUD is properly positioned:

• Selective serotonin reuptake inhibitors (SSRIs) are the drugs of choice for improving both physical and mood symptoms of PMS/PMDD, with proven efficacy in large bodies of evidence. 1, 2, 6
• SSRIs can be used either continuously or during the luteal phase only, depending on symptom severity and patient preference. 1
• The Mirena IUD can remain in place while treating with SSRIs, as there are no contraindications to this combination. 6

Step 3: Consider IUD Removal if Appropriate

Remove the Mirena IUD if:

• Symptoms persist despite adequate SSRI trial and the patient strongly suspects the progestin is contributing to mood symptoms. 6
• The patient desires to switch to a non-hormonal contraceptive method. 6
• Replace with a copper IUD if non-hormonal contraception is desired, as copper IUDs do not affect mood symptoms related to progestin exposure. 6

Step 4: Alternative Hormonal Approach

If the patient wants to continue hormonal contraception but remove the Mirena:

• Consider switching to a combined hormonal contraceptive pill containing 20 mcg ethinyl estradiol/3 mg drospirenone in a 24/4 extended cycle regimen, which has been shown to significantly improve emotional and physical symptoms of PMDD. 6
• Other monophasic, extended-cycle combined hormonal contraceptive pills with less androgenic progestins may also be helpful. 6
• Avoid other progestin-only methods (progestin-only pill, etonogestrel implant, depot medroxyprogesterone acetate) as these have similar or greater potential to negatively affect mood. 6

Critical Clinical Pitfall

Do not automatically attribute new mood symptoms to the IUD without first investigating potential underlying causes, including perimenopause, thyroid dysfunction, new psychiatric conditions, or life stressors. 4 The CDC specifically warns against this attribution bias, as it can lead to unnecessary IUD removal without addressing the actual cause of symptoms. 4

Counseling Points

• Reassure the patient that PMS affects 30-40% of reproductive-age women and that effective treatments exist. 1
• Explain that if perimenopause is the underlying cause, symptoms may continue or worsen regardless of contraceptive method until menopause is reached. 1, 2
• Discuss that lifestyle modifications (regular exercise, stress reduction, adequate sleep) and cognitive behavioral therapy can provide additional benefit alongside pharmacological treatment. 1