Residency · Residency · Rheumatology

Pregnancy in Rheumatic Disease

Introduction

Pregnancy planning is an essential component of comprehensive care for women with rheumatic diseases, as many commonly used medications are teratogenic and disease activity during pregnancy significantly impacts maternal and fetal outcomes. The key principle guiding management is that disease control before conception is the strongest predictor of favorable pregnancy outcomes. Active disease during pregnancy increases the risk of disease flare, preeclampsia, intrauterine growth restriction, preterm birth, and fetal loss. The 2020 ACR reproductive health guideline provides comprehensive evidence-based recommendations for managing the intersection of rheumatic disease and pregnancy. Optimal care requires multidisciplinary collaboration among the rheumatologist, maternal-fetal medicine specialist, and neonatologist.

Preconception Counseling

Disease Control

Achieving disease remission or at minimum low disease activity for at least 6 months before conception is fundamental to optimizing pregnancy outcomes. Active systemic lupus erythematosus at conception confers a 2- to 3-fold higher risk of disease flare during pregnancy. Active rheumatoid arthritis is associated with preterm birth and low birth weight. Lupus nephritis demands particular attention: nephritis should be in remission for at least 6 months before pregnancy, as active nephritis substantially increases the risk of preeclampsia and fetal loss.

Medication Review (ESSENTIAL Pre-conception)

A thorough medication review is essential prior to conception. Teratogenic medications must be discontinued with adequate washout periods. Methotrexate should be stopped at least 3 months before conception in both men and women per the 2020 ACR guideline. Mycophenolate mofetil and mycophenolic acid must be stopped at least 6 weeks before conception, with transition to azathioprine for maintenance immunosuppression. Leflunomide requires cholestyramine washout (8 g three times daily for 11 days) followed by confirmation of undetectable serum levels due to its extremely long half-life. Cyclophosphamide is both teratogenic and gonadotoxic and must be stopped well in advance of conception. Thalidomide and lenalidomide are absolutely contraindicated. JAK inhibitors, including tofacitinib, baricitinib, and upadacitinib, have demonstrated teratogenicity in animal studies and should be stopped before conception. The transition to pregnancy-compatible medications should be completed before conception occurs, not after pregnancy is discovered.

Antibody Assessment

Specific antibody testing prior to pregnancy provides critical risk stratification. Anti-Ro/SSA and anti-La/SSB antibodies should be screened in all women with SLE, Sjogren syndrome, mixed connective tissue disease, and undifferentiated connective tissue disease. Anti-Ro positivity confers a risk of neonatal lupus, most significantly congenital heart block, which occurs in approximately 2 percent of anti-Ro positive pregnancies and recurs in approximately 18 percent of subsequent pregnancies after a prior affected child. Antiphospholipid antibodies, including anticardiolipin antibodies, anti-beta2-glycoprotein I, and lupus anticoagulant, should be assessed because their presence increases the risk of pregnancy loss, preeclampsia, intrauterine growth restriction, and placental insufficiency. Baseline anti-dsDNA and complement levels (C3/C4) should be established for SLE patients to enable meaningful monitoring during pregnancy.

Medications in Pregnancy

Compatible (Safe to Continue)

Hydroxychloroquine should be continued throughout pregnancy and breastfeeding without interruption. It reduces SLE flares during pregnancy, reduces neonatal lupus risk including congenital heart block, and has no teratogenicity. The PATCH trial provided pilot data that HCQ at 400 mg daily reduced recurrence of congenital heart block in anti-Ro positive women with a prior affected pregnancy. The evidence for both safety and benefit makes hydroxychloroquine one of the most important medications in rheumatologic pregnancy management.

Azathioprine is compatible with pregnancy at doses up to 2 mg/kg/day. A protective metabolic feature is that the fetal liver lacks inosinate pyrophosphorylase, the enzyme required to convert azathioprine to its active metabolite, limiting fetal drug exposure. It is used for maintenance therapy in SLE, vasculitis, and myositis during pregnancy.

Sulfasalazine is compatible with pregnancy but requires supplementation with folic acid at 5 mg daily rather than the standard prenatal dose. It is used for rheumatoid arthritis and inflammatory bowel disease management during pregnancy.

Colchicine is compatible with pregnancy and should be continued for familial Mediterranean fever, as discontinuation risks both disease flare and amyloidosis progression.

Low-dose aspirin at 81 to 150 mg daily, initiated at 12 weeks of gestation, is recommended for preeclampsia prevention in women with SLE and antiphospholipid antibody-positive patients.

Glucocorticoids are compatible with pregnancy at the lowest effective dose. Prednisone and prednisolone are preferred because they are extensively metabolized by placental 11-beta-hydroxysteroid dehydrogenase type 2, resulting in minimal fetal exposure. Dexamethasone and betamethasone cross the placenta and are used only when a fetal effect is specifically intended, such as treatment of congenital heart block or promotion of fetal lung maturity. Glucocorticoid risks during pregnancy include gestational diabetes, hypertension, preeclampsia, premature rupture of membranes, and cleft palate with first-trimester high-dose exposure.

Tacrolimus is compatible with pregnancy and is used for lupus nephritis maintenance when mycophenolate is contraindicated. Drug levels should be monitored, as dose adjustment may be required during pregnancy.

Certolizumab pegol is the preferred biologic for use during pregnancy because it lacks an Fc region and therefore does not cross the placenta. The CRIB study confirmed minimal to no placental transfer, with no drug detected in infant blood. Other TNF inhibitors, including infliximab, adalimumab, golimumab, and etanercept, can be continued through the first and second trimesters but cross the placenta through FcRn-mediated IgG transport. Consideration should be given to stopping these agents at 20 to 30 weeks of gestation to minimize neonatal drug exposure. Infants exposed to biologics in utero should have live vaccines delayed until 6 to 7 months of age.

Rituximab, if administered before pregnancy, may produce persistent B cell depletion; if given during pregnancy, neonatal B cell depletion is possible. It should be avoided during pregnancy when possible.

Contraindicated (Must Stop Before Conception)

Methotrexate is FDA category X and causes neural tube defects, limb defects, and craniofacial anomalies. It must be stopped at least 3 months before conception in both women and men. Inadvertent exposure requires high-dose folic acid supplementation and perinatology consultation.

Mycophenolate mofetil causes ear and facial malformations, cleft palate, and cardiac defects. It must be stopped at least 6 weeks before conception with transition to azathioprine. An FDA Risk Evaluation and Mitigation Strategy program is in place for pregnancy prevention.

Leflunomide is teratogenic, causing craniofacial and skeletal defects in animal studies. Its very long half-life necessitates cholestyramine washout, with verification that serum levels are below 0.02 mg/L on two tests separated by at least 14 days.

Cyclophosphamide is teratogenic during the first trimester and gonadotoxic, potentially causing premature ovarian failure. GnRH agonist co-treatment may help preserve ovarian function. Sperm banking should be offered to men before cyclophosphamide therapy.

JAK inhibitors have demonstrated teratogenicity in animal studies at therapeutic doses and must be discontinued before conception. Thalidomide, the most potent known human teratogen, causes phocomelia and is absolutely contraindicated.

<image>A comprehensive medication safety chart for pregnancy in rheumatic disease, organized as a traffic light system. GREEN (compatible/continue): Hydroxychloroquine, azathioprine (≤2 mg/kg), sulfasalazine + folic acid, colchicine, prednisone/prednisolone (lowest dose), certolizumab pegol, tacrolimus, low-dose aspirin, acetaminophen. YELLOW (limited data/use with caution): TNF inhibitors other than certolizumab (continue through 2nd trimester, consider stopping at 20-30 weeks), rituximab (avoid during pregnancy; plan timing), cyclosporine (compatible but monitor), IVIG (compatible for specific indications). RED (contraindicated/must stop before conception): Methotrexate (stop ≥3 months), mycophenolate (stop ≥6 weeks), leflunomide (washout required), cyclophosphamide, JAK inhibitors, thalidomide. For each drug, include the fetal risk and washout period. Include a note: "Certolizumab pegol is the ONLY biologic that does not cross the placenta."</image>

Disease-Specific Considerations

SLE in Pregnancy

Lupus flare risk during pregnancy and the postpartum period ranges from 25 to 65 percent, with higher rates in women with active disease at conception. One of the most challenging diagnostic dilemmas in obstetric rheumatology is distinguishing an SLE flare from preeclampsia, as both can present with hypertension, proteinuria, and thrombocytopenia. Key differentiating features include rising anti-dsDNA and falling complement in SLE flare versus normal or rising complement and elevated sFlt-1/PlGF ratio in preeclampsia. Active urinary sediment and extra-renal lupus features favor flare, while elevated uric acid and liver enzymes favor preeclampsia. SLE flare responds to immunosuppression, while preeclampsia resolves with delivery. These two conditions can coexist, making differentiation particularly challenging. Active lupus nephritis at conception portends poor outcomes; patients should be in remission for at least 6 months. Those on mycophenolate for nephritis maintenance must be switched to azathioprine before conception, with tacrolimus as an alternative. Monitoring during pregnancy should include monthly visits with complete blood count, basic metabolic panel, urinalysis, urine protein-to-creatinine ratio, complement levels, and anti-dsDNA at each visit.

Neonatal Lupus

Neonatal lupus is caused by transplacental passage of maternal anti-Ro/SSA antibodies, and less commonly anti-La/SSB antibodies. Congenital heart block is the most serious manifestation, occurring in approximately 2 percent of pregnancies in anti-Ro positive mothers, with an 18 percent recurrence rate in women with a previously affected child. Complete heart block usually develops between 18 and 24 weeks of gestation, corresponding to the period of increasing maternal IgG transfer. Once established, complete heart block is usually irreversible; approximately 65 percent of affected infants require permanent pacemaker placement, and mortality is approximately 20 percent. Fetal echocardiography should be performed weekly or biweekly from 16 to 26 weeks of gestation for surveillance. Fluorinated glucocorticoids, specifically dexamethasone at 4 mg daily, may be administered for incomplete heart block (first-degree or second-degree) to prevent progression, though their use for established third-degree block is controversial. Hydroxychloroquine reduces the risk of congenital heart block and should be continued throughout pregnancy in all anti-Ro positive women. Intravenous immunoglobulin is under investigation for prevention in high-risk pregnancies with prior affected children. Neonatal lupus rash presents as annular polycyclic erythematous lesions appearing weeks after birth with sun exposure and resolves by 6 to 8 months as maternal antibodies are cleared. Hepatic and hematologic manifestations, including transient cytopenias and hepatitis, are self-limited.

Antiphospholipid Syndrome in Pregnancy

Obstetric antiphospholipid syndrome manifests as recurrent early miscarriage, late fetal loss, preeclampsia and HELLP syndrome, and placental insufficiency. The standard of care treatment protocol consists of low-dose aspirin at 81 to 150 mg daily from the first trimester combined with prophylactic-dose low-molecular-weight heparin (enoxaparin 40 mg subcutaneously daily). Therapeutic-dose LMWH is used in patients with prior thrombotic events. LMWH is continued throughout pregnancy and for 6 weeks postpartum, at which point patients can transition to warfarin if indicated; LMWH rather than warfarin must be used during pregnancy. For refractory obstetric APS with recurrent losses despite standard therapy, additional interventions include hydroxychloroquine at 200 to 400 mg daily, low-dose prednisone at 10 mg daily during the first trimester, and intravenous immunoglobulin, though data supporting the latter are controversial. Pravastatin is under investigation in the IMPACT study for refractory obstetric APS.

RA in Pregnancy

Rheumatoid arthritis naturally improves during pregnancy in approximately 50 to 75 percent of patients, a phenomenon that may relate to the immune tolerance required to sustain pregnancy. However, postpartum flare is common in the first 3 to 6 months after delivery, and plans for resumption of DMARDs should be established in advance. Compatible medications during pregnancy include hydroxychloroquine, sulfasalazine, low-dose prednisone, certolizumab pegol, and azathioprine. TNF inhibitors can be continued through the second trimester, with certolizumab preferred due to its lack of placental transfer. During breastfeeding, hydroxychloroquine, sulfasalazine, prednisone, certolizumab, and infliximab (which has minimal breast milk transfer) are all compatible. Methotrexate must be stopped at least 3 months before conception and can be resumed postpartum when the patient is not breastfeeding or after breastfeeding ends.

Vasculitis in Pregnancy

Vasculitis during pregnancy is rare but poses significant management challenges. For ANCA-associated vasculitis, azathioprine should be used for maintenance therapy in place of cyclophosphamide and mycophenolate. Glucocorticoids manage flares, and rituximab may be considered in critical situations. Takayasu arteritis may worsen during pregnancy, requiring glucocorticoids and azathioprine with close monitoring for aortic complications. Blood pressure, renal function, and proteinuria should be monitored closely throughout pregnancy.

Male Fertility and Paternal Medication Exposure

The 2020 ACR guideline made an important revision regarding methotrexate and male fertility: men do not need to stop methotrexate before conception. Low-dose methotrexate does not affect sperm quality or increase the risk of birth defects. Sulfasalazine causes reversible oligospermia, and consideration should be given to stopping it 2 to 3 months before conception or switching to an alternative. Cyclophosphamide is gonadotoxic and can cause azoospermia in a dose-dependent manner; sperm banking should be offered before treatment. GnRH agonist co-treatment has less evidence for fertility preservation in males compared to females. TNF inhibitors, azathioprine, and hydroxychloroquine have no evidence of adverse paternal effects and can be continued. Mycophenolate and JAK inhibitors have limited data, and current guidelines generally recommend discontinuation before paternal conception.

Breastfeeding Compatibility

Medications compatible with breastfeeding include hydroxychloroquine, prednisone at doses up to 20 mg daily, azathioprine, sulfasalazine, colchicine, certolizumab pegol (which lacks an Fc region and has minimal milk transfer), and NSAIDs with ibuprofen preferred. Medications with limited data but likely compatible include infliximab, adalimumab, etanercept, and rituximab, all of which are large molecules with minimal milk transfer. Medications to avoid during breastfeeding include methotrexate, mycophenolate, cyclophosphamide, leflunomide, and JAK inhibitors due to insufficient safety data.

Contraception in Rheumatic Disease

Estrogen-containing oral contraceptive pills should be avoided in SLE patients with antiphospholipid antibodies, those with active SLE, and patients with antiphospholipid syndrome due to increased thrombosis risk. The SELENA trial demonstrated that oral contraceptive pills are safe in women with stable, antiphospholipid antibody-negative SLE. Progesterone-only methods are safe in SLE and APS and are the preferred hormonal option. Intrauterine devices, both levonorgestrel-releasing and copper, are safe and highly effective, with no increased infection risk in immunosuppressed patients. Emergency contraception is safe and carries no specific contraindications in rheumatic diseases.

<image>A pregnancy management timeline for a woman with SLE and positive anti-Ro/SSA antibodies. Show a horizontal timeline from preconception through postpartum. Preconception (≥6 months before): Achieve disease remission, switch MTX/MMF to AZA, start/continue HCQ, check anti-Ro/SSA, anti-La/SSB, aPL, complement, anti-dsDNA, baseline labs. First trimester: Continue HCQ + AZA + low-dose aspirin (if aPL+ or SLE), start LMWH if obstetric APS history, monthly rheumatology visits (CBC, BMP, complement, anti-dsDNA, UPCR). Weeks 16-26: Fetal echocardiography weekly/biweekly (anti-Ro+ monitoring for CHB). Second trimester: Continue monitoring, consider stopping non-certolizumab TNFi at 20-30 weeks. Third trimester: Monitor for preeclampsia vs SLE flare (sFlt-1/PlGF ratio, complement trends), plan delivery timing and LMWH management. Postpartum: Resume full DMARDs when no longer breastfeeding (or use compatible medications), monitor for SLE flare (first 3-6 months highest risk), continue HCQ. Mark key decision points and monitoring tests at each stage.</image>

Key Clinical Pearls

• Hydroxychloroquine should NEVER be stopped during pregnancy in SLE; it reduces flares, prevents CHB, and is proven safe
• Certolizumab pegol is the only biologic that does not cross the placenta and is the preferred biologic during pregnancy
• Distinguish SLE flare from preeclampsia using complement levels (falling in SLE, stable/rising in preeclampsia) and anti-dsDNA trends
• Men on low-dose methotrexate do NOT need to stop before conception (2020 ACR guideline change)
• Mycophenolate must be switched to azathioprine at least 6 weeks before conception
• Anti-Ro/SSA positive women need fetal echocardiography from 16-26 weeks to monitor for congenital heart block

References

1. Sammaritano LR, et al. 2020 American College of Rheumatology Guideline for the Management of Reproductive Health in Rheumatic and Musculoskeletal Diseases. Arthritis Care Res. 2020;72(4):461-488.
2. Clowse ME, et al. The impact of increased lupus activity on obstetric outcomes. Arthritis Rheum. 2005;52(2):514-521.
3. Izmirly PM, et al. Hydroxychloroquine to prevent recurrent congenital heart block in fetuses of anti-SSA/Ro-positive mothers (PATCH trial). J Am Coll Cardiol. 2020;76(3):292-302.
4. Mariette X, et al. Lack of placental transfer of certolizumab pegol during pregnancy (CRIB study). Ann Rheum Dis. 2018;77(2):228-233.
5. Andreoli L, et al. EULAR recommendations for women's health and the management of family planning, assisted reproduction, pregnancy and menopause in patients with systemic lupus erythematosus and/or antiphospholipid syndrome. Ann Rheum Dis. 2017;76(3):476-485.

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