For clinicians

Hydroxychloroquine

Plaquenil, HCQ, antimalarial

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Bottom lineBottom line: hydroxychloroquine is generally continued throughout pregnancy and lactation and is often actively encouraged in SLE. Discontinuation is associated with increased flare risk. In anti-Ro/SSA-positive pregnancies with a previously affected child, it reduces recurrence of congenital heart block. Considered compatible with breastfeeding and with paternal exposure. Broad agreement across ACR 2020, EULAR 2024, and BSR 2022/23.

By reproductive phase

PhasePositionDetailEvidence
Pre-conceptionContinueContinue. In SLE, established pre-conception use is associated with lower flare risk and improved pregnancy outcomes.[1, 2, 3]●●●○moderate evidencestrong
1st trimesterContinueContinue. In the largest claims-database study (Huybrechts 2021; 2,045 hydroxychloroquine-exposed vs 21,679 reference deliveries, restricted to rheumatic disorders and propensity-score matched), overall major malformations were modestly increased: RR 1.26 (95% CI 1.04 to 1.54). The signal sat in the higher dose band: RR 0.95 (0.60 to 1.50) at <400 mg/day versus RR 1.33 (1.08 to 1.65) at >=400 mg/day. In the all-dose subtype analysis two categories reached significance: oral clefts RR 3.70 (1.55 to 8.82) and urinary malformations RR 2.21 (1.26 to 3.86), both on small event counts (fewer than 11 exposed oral cleft cases). Cardiac, respiratory, gastrointestinal, genital, musculoskeletal, and limb subtypes were not significantly raised. Note the dose-stratified analysis covered overall malformations only and was never broken down by subtype, which is why the EULAR SLR describes the >=400 mg/day finding as showing no specific pattern; the subtype signals come from the separate all-dose analysis. A subsequent prospective cohort (Chambers 2022, MotherToBaby/OTIS) did not confirm any increase, against either disease-matched (OR 1.08, 0.51 to 2.29) or healthy comparators (aOR 0.76, 0.28 to 2.05). The Huybrechts authors state the finding should not necessarily alter the treatment recommendation, and note most study limitations would bias toward the null while live-birth-only ascertainment could understate risk. EULAR 2024 and BSR 2023 both weighed this evidence and still recommend continuation.[1, 2, 3, 6, 7, 8]●●●○moderate evidencestrong
2nd/3rd trimesterContinueContinue through delivery.[1, 2, 3]●●●○moderate evidencestrong
BreastfeedingContinueCompatible with lactation; low relative infant dose.[2, 3]●●●○moderate evidencestrong
PaternalContinueCompatible with paternal exposure on current evidence.[2, 3]●●○○low evidenceconditional

Guideline comparison

GuidelinePositionStrength
ACR 2020Strongly recommend continuing hydroxychloroquine before pregnancy, during pregnancy, and in breastfeeding (Table 3: ++/++/++). If already taking it, strongly continue; if not, conditionally recommend starting when there is no contraindication. All women with SLE are advised to take it in pregnancy if possible. Paternal: strongly recommend continuing.[1]Strong (continue); conditional (start if not already on it)
EULAR 2024Compatible with pregnancy (LoE 2a/GoR B) and lactation (2a/B); continuable in male patients (2c/C).[2]Oxford LoE/GoR as shown
BSR 2022/23Compatible (<=400 mg/day) at peri-conception, first trimester, second/third trimester, breastfeeding, and paternal exposure.[3]Verified against BSR Table 1
=Guideline agreement. VERIFIED AGREEMENT. EULAR 2024 (pregnancy 2a/B, lactation 2a/B, male 2c/C) and BSR 2023 (compatible across all five phases, <=400 mg/day) agree. Hydroxychloroquine is the least contested drug in reproductive rheumatology.
=Guideline agreement. Both guidelines considered the same malformation evidence and both still recommend continuation. EULAR's SLR records no malformation risk at <=400 mg/day and a slight increase at >=400 mg/day without a specific pattern, unconfirmed by a later prospective cohort. That 'no specific pattern' describes the dose-stratified analysis, which covered overall malformations only. In its separate all-dose subtype analysis the same paper did report raised oral cleft and urinary malformation risks, on small event counts. BSR cites the prospective cohort as reassuring at any dose. Neither guideline treats any of this as grounds to stop or withhold the drug.

Key points

PointEvidence
Discontinuation is associated with increased SLE flare risk; continuation is protective. BSR 2023 notes that stopping hydroxychloroquine in pregnancy may increase the risk of disease flares and fetal loss, and that flares in turn drive the need for drugs with greater potential risk.[1, 3, 4]●●●○moderate evidencestrong
BSR 2023 recommends continuing hydroxychloroquine in pregnancy at 400 mg/day (GRADE 1B, 100% SOA). The 400 mg/day ceiling derives from general ophthalmic-risk dosing guidance outside pregnancy, not from a fetal safety signal, because pregnancy pharmacokinetics reduce the reliability of weight-based dosing. EULAR's SLR reports no congenital malformation risk at doses up to 400 mg/day, consistent with Huybrechts (RR 0.95, 95% CI 0.60 to 1.50, below 400 mg/day).[3, 6, 7]●●●○moderate evidencestrong
In anti-Ro/SSA-positive pregnancies with a prior child affected by congenital heart block, hydroxychloroquine 400 mg daily started by 10 weeks reduced recurrence of advanced (2nd/3rd degree) block to about 7.4%, versus a historical rate near 18% (PATCH, single-arm).[5]●●●○moderate evidenceconditional
Observational signal for reduced pre-eclampsia and adverse pregnancy outcomes; evidence is of lower quality.[4]●●○○low evidenceconditional

Special populations

Monitoring

References

  1. Sammaritano LR, et al. 2020 ACR Guideline for the Management of Reproductive Health in Rheumatic and Musculoskeletal Diseases. Arthritis Rheumatol. 2020;72(3):529-556. https://acrjournals.onlinelibrary.wiley.com/doi/10.1002/art.41191
  2. Ruegg L, et al. EULAR recommendations for use of antirheumatic drugs in reproduction, pregnancy, and lactation: 2024 update. Ann Rheum Dis. 2025;84(6):910-926. https://ard.eular.org/article/S0003-4967(25)00818-0/fulltext
  3. Russell MD, et al. BSR guideline on prescribing drugs in pregnancy and breastfeeding: immunomodulatory anti-rheumatic drugs and corticosteroids. Rheumatology (Oxford). 2023;62(4):e48-e88. https://academic.oup.com/rheumatology/article/62/4/e48/6783012
  4. Tarter L, Bermas BL. Expert Perspective: Lupus and Pregnancy. Arthritis Rheumatol. 2024;76(3):321-331. https://acrjournals.onlinelibrary.wiley.com/doi/10.1002/art.42756
  5. Izmirly P, et al. Hydroxychloroquine to Prevent Recurrent Congenital Heart Block in Fetuses of Anti-SSA/Ro-Positive Mothers (PATCH). J Am Coll Cardiol. 2020;76(3):292-302. https://www.jacc.org/doi/10.1016/j.jacc.2020.05.045
  6. Pluma A, Hamroun S, Ruegg L, Cecchi I, Kramer M, Perez-Garcia LF, et al. Antirheumatic drugs in reproduction, pregnancy, and lactation: a systematic literature review informing the 2024 update of the EULAR recommendations. Ann Rheum Dis. 2025. doi:10.1016/j.ard.2025.02.021. https://doi.org/10.1016/j.ard.2025.02.021
  7. Huybrechts KF, Bateman BT, Zhu Y, Straub L, Mogun H, Kim SC, et al. Hydroxychloroquine early in pregnancy and risk of birth defects. Am J Obstet Gynecol. 2021;224(3):290.e1-290.e22. (Figures 1 and 2 and the Discussion, pages 290.e6-290.e7, read directly; remainder of the full text not read.)
  8. Chambers CD, Johnson DL, Xu R, Luo Y, Felix R, Fine M, et al. Birth outcomes in women who have taken hydroxychloroquine during pregnancy: a prospective cohort study. Arthritis Rheumatol. 2022;74(4):711-724. (Cited via the EULAR 2024 SLR and BSR 2023; primary text not yet read.)