What are the treatment options for a pregnant patient with melasma (Chloasma)?

Treatment of Melasma (Chloasma) During Pregnancy

The primary management of melasma during pregnancy is strict photoprotection with broad-spectrum sunscreen (SPF 50+ with high UVA protection) starting from the first trimester, as active treatment with depigmenting agents should be avoided until after delivery.

Photoprotection: The Cornerstone of Management

Rigorous sun protection is the only evidence-based intervention safe and effective during pregnancy 1, 2:

• Apply broad-spectrum sunscreen daily with SPF 50+ and UVA-PF ≥28 starting in the first trimester 1
• Physical blockers (titanium dioxide, zinc oxide) are preferred over chemical blockers due to broader protection and minimal systemic absorption 3
• Reapply sunscreen every 2 hours during sun exposure 1
• Use additional physical barriers: wide-brimmed hats, protective clothing, and seek shade 3, 4
• Avoid peak sun hours (10 AM to 4 PM) 2

Clinical evidence demonstrates that proper photoprotection reduces melasma incidence from 53% to 2.7% in pregnant women 1. In one controlled trial, only 5 out of 185 pregnant women using broad-spectrum sunscreen developed new melasma, compared to historical rates exceeding 50% 1.

What NOT to Use During Pregnancy

Hydroquinone is contraindicated during pregnancy 5:

• Hydroquinone is Pregnancy Category C with unknown fetal harm potential 5
• Animal reproduction studies have not been conducted with topical hydroquinone 5
• Despite being the mainstay treatment for melasma outside pregnancy, it should NOT be used until after delivery 3

Avoid all systemic and most topical depigmenting agents during pregnancy 3:

• Tretinoin and other retinoids are teratogenic 6
• Medium-depth chemical peels carry unpredictable results and potential adverse effects 3
• Laser treatments should be deferred until postpartum 3

Safe Topical Options (Limited Evidence)

Azelaic acid 20% may be considered if treatment is deemed absolutely necessary 6, 7:

• Pregnancy Category B with no teratogenic effects observed in animal studies 7
• Provides comedolytic, antibacterial, and anti-inflammatory effects 6
• Particularly beneficial for darker skin types due to lightening effect on post-inflammatory hyperpigmentation 6
• However, embryotoxic effects were observed in animals at very high oral doses (2500 mg/kg/day in rats) within toxic dose ranges 7
• Should only be used if clearly needed, as there are no adequate well-controlled studies in pregnant women 7

Vitamin D Supplementation

Oral vitamin D supplementation should be recommended to prevent deficiency while avoiding UV exposure 4:

• Strict photoprotection can lead to vitamin D deficiency 4
• Supplementation allows continued sun avoidance without nutritional consequences 4

Patient Counseling and Expectations

Educate patients that melasma during pregnancy is self-limited but requires patience 3, 2:

• Spontaneous resolution typically occurs postpartum but may take months 3
• Up to 30% of cases persist after delivery, even up to 10 years later 2
• Recurrence and aggravation are common in subsequent pregnancies 2
• Prevention through photoprotection is far more effective than treatment 1, 2

Risk Factors to Discuss

Identify patients at higher risk who need more aggressive photoprotection 8:

• Skin types I-II (lighter skin) show significantly better response to photoprotection 8
• History of melasma in previous pregnancies increases recurrence risk 2
• Use of cosmetics may influence melasma development 8
• UV-B, UV-A, and visible light all stimulate melanogenesis 3

Common Pitfalls to Avoid

• Do NOT prescribe hydroquinone during pregnancy, even though it is the standard treatment outside pregnancy—wait until postpartum 5, 3
• Do NOT delay photoprotection until melasma appears—start broad-spectrum sunscreen from the first trimester for prevention 1, 2
• Do NOT use destructive modalities (cryotherapy, medium-depth peels, lasers) during pregnancy due to unpredictable results and potential adverse effects 3
• Do NOT reassure patients that all melasma resolves quickly postpartum—up to 30% of cases persist long-term, so prevention is critical 2
• Do NOT forget vitamin D supplementation when recommending strict sun avoidance 4

Postpartum Treatment Planning

Defer active treatment with depigmenting agents until after delivery and lactation 5, 3:

• Hydroquinone can be initiated postpartum but exercise caution during breastfeeding 5
• Topical tretinoin and combination therapies become options after pregnancy 3
• Laser and procedural treatments can be considered postpartum 3