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PubMed This is a summary of 17 peer-reviewed journal articles Updated
Obstetrics

Prenatal Monitoring and Treatments

At a Glance

For pregnancies at risk of congenital heart block, critical monitoring with fetal echocardiograms happens between weeks 16 and 26. Your doctor may recommend home Doppler checks and prescribe medications like hydroxychloroquine to protect the baby's heart and significantly lower recurrence risks.

When you are at risk for congenital heart block (CHB), your pregnancy journey becomes a process of careful “watchful waiting.” Because the window of risk for heart block typically occurs between weeks 16 and 26 of pregnancy, your medical team will create a structured surveillance plan to monitor your baby’s heart rhythm during this critical time [1][2].

The Surveillance Timeline

The gold standard for monitoring is fetal echocardiography, a specialized ultrasound that looks specifically at the baby’s heart structure and electrical timing.

  • Critical Window: Monitoring usually begins around week 16 and continues weekly or biweekly through week 26 [1].
  • Watching for Hydrops Fetalis: One of the main reasons doctors monitor the baby so closely is to check for hydrops fetalis, which is a condition where the baby’s heart fails to pump effectively, leading to fluid buildup in the baby’s body [3][4]. Catching heart distress early allows the medical team to intervene or deliver the baby safely before hydrops becomes severe.
  • Limitations: Because heart block can sometimes progress from a normal rhythm to a complete block in as little as 24 hours, even weekly ultrasounds might miss the exact moment the rhythm changes [5][6].

Emerging Tools: Home Monitoring

To address the “gaps” between doctor appointments, many specialists now support home fetal heart rate monitoring (FHRM) [5][7]. Parents use a handheld Doppler device to listen to the baby’s heart rate once or twice a day. If you hear a heart rate that is unusually slow or “skipped,” you contact your team for an immediate echocardiogram [5].

  • A Crucial Warning: Home monitoring requires specific, hands-on training from your medical team. It is very common to mistake your own resting heart rate (which is slower) for the baby’s heart rate. If you mistake your pulse for the baby’s, you might receive false reassurance or experience unnecessary panic. Your team will teach you how to tell the difference accurately.

Preventative Treatments

If you have had a previous pregnancy affected by CHB, the risk of it happening again is roughly 18%. However, certain medications can significantly lower this risk.

  • Hydroxychloroquine (HCQ): This is the current standard for “secondary prevention” (preventing a recurrence). Studies show that taking HCQ can reduce the risk of heart block returning by more than 50% [8][9]. It is generally considered safe for the baby and is often started before or early in pregnancy [10][11].
  • Intravenous Immunoglobulin (IVIG): In some high-risk cases, doctors may use IVIG to help “neutralize” the maternal antibodies before they can damage the fetal heart, though this is often used in combination with other treatments [12][13].

The Steroid Controversy

You may hear about fluorinated steroids (such as dexamethasone). Their use is controversial in the medical community [14][15]. Current evidence does not support using steroids for an established 3rd-degree (complete) block. At this stage, the “wiring” is already scarred, and steroids do not improve survival or change the need for a pacemaker [16][17]. Furthermore, long-term steroid use during pregnancy can have side effects for both the mother and the baby’s growth [16].

Looking Ahead: Future Pregnancies

If your current pregnancy is affected by autoimmune CHB, you may wonder what this means for future family planning. While the recurrence risk in a subsequent pregnancy is elevated (up to ~18%), the prophylactic use of medications like HCQ under the guidance of a multidisciplinary team can drastically improve the odds of a healthy outcome in the future [8][9].

Common questions in this guide

When is the most critical time for fetal heart monitoring?
The most critical window for monitoring a baby's heart rhythm is between weeks 16 and 26 of pregnancy. During this time, your medical team will likely recommend weekly or biweekly fetal echocardiograms to closely watch the baby's heart function.
What is hydrops fetalis and why do doctors look for it?
Hydrops fetalis is a serious complication where fluid builds up in the baby's body because the heart is failing to pump effectively. Close prenatal monitoring helps doctors catch early signs of heart distress so they can intervene before severe hydrops develops.
Can I monitor my baby's heart rate at home?
Yes, many specialists support home monitoring using a handheld Doppler to check the baby's heart rate daily. However, you must receive specific, hands-on training from your doctor to ensure you do not mistake your own resting heart rate for the baby's heartbeat.
What treatments can prevent congenital heart block from happening again?
If you had a previous pregnancy affected by congenital heart block, doctors often prescribe a medication called hydroxychloroquine (HCQ). Studies show that taking HCQ can reduce the risk of the condition returning in future pregnancies by more than 50 percent.
Are steroids used to treat complete heart block?
Current medical evidence does not support using fluorinated steroids like dexamethasone for an established complete heart block. At this third-degree stage, the heart's electrical wiring is already scarred, and steroids do not improve outcomes but can cause side effects for both mother and baby.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.How often will I need fetal echocardiograms, and at which weeks of my pregnancy is monitoring most critical?
  2. 2.Are there any signs of 'hydrops fetalis' on the current ultrasound?
  3. 3.Given my history and antibody levels, what is the specific benefit of hydroxychloroquine (HCQ) for me?
  4. 4.If I choose home monitoring, how can I be trained to accurately distinguish the baby's heart rate from my own pulse?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

References

References (17)
  1. 1

    Congenital Complete Atrioventricular Heart Block in a Pregnant Woman with Sjögren Syndrome: Prenatal Care Follow-Up and the Challenge of Intrauterine Treatment.

    Carrilho MC, Bravo-Valenzuela NJ, Araujo Júnior E

    Revista brasileira de ginecologia e obstetricia : revista da Federacao Brasileira das Sociedades de Ginecologia e Obstetricia 2020; (42(4)):228-232 doi:10.1055/s-0040-1709738.

    PMID: 32330965
  2. 2

    Serial echocardiography for immune-mediated heart disease in the fetus: results of a risk-based prospective surveillance strategy.

    Kan N, Silverman ED, Kingdom J, et al.

    Prenatal diagnosis 2017; (37(4)):375-382 doi:10.1002/pd.5021.

    PMID: 28177533
  3. 3

    Treatment of Fetal Arrhythmias.

    Veduta A, Panaitescu AM, Ciobanu AM, et al.

    Journal of clinical medicine 2021; (10(11)) doi:10.3390/jcm10112510.

    PMID: 34204066
  4. 4

    Complete Heart Block in the Fetus: An Antenatal Complication of Sjögren's Syndrome.

    Videnie M, Poalelungi CV, Chiriac A, et al.

    Life (Basel, Switzerland) 2025; (15(12)) doi:10.3390/life15121890.

    PMID: 41465829
  5. 5

    Home Monitoring for Fetal Heart Rhythm During Anti-Ro Pregnancies.

    Cuneo BF, Sonesson SE, Levasseur S, et al.

    Journal of the American College of Cardiology 2018; (72(16)):1940-1951 doi:10.1016/j.jacc.2018.07.076.

    PMID: 30309472
  6. 6

    Novel approaches to the surveillance and management of fetuses at risk for anti-Ro/SSA mediated atrioventricular block.

    Kaplinski M, Cuneo BF

    Seminars in perinatology 2022; (46(4)):151585 doi:10.1016/j.semperi.2022.151585.

    PMID: 35410713
  7. 7

    Prospective Evaluation of High Titer Autoantibodies and Fetal Home Monitoring in the Detection of Atrioventricular Block Among Anti-SSA/Ro Pregnancies.

    Buyon JP, Masson M, Izmirly CG, et al.

    Arthritis & rheumatology (Hoboken, N.J.) 2024; (76(3)):411-420 doi:10.1002/art.42733.

    PMID: 37947364
  8. 8

    Hydroxychloroquine to Prevent Recurrent Congenital Heart Block in Fetuses of Anti-SSA/Ro-Positive Mothers.

    Izmirly P, Kim M, Friedman DM, et al.

    Journal of the American College of Cardiology 2020; (76(3)):292-302 doi:10.1016/j.jacc.2020.05.045.

    PMID: 32674792
  9. 9

    Hydroxychloroquine in systemic lupus erythematosus, anti-SSA/SSB, and antiphospholipid antibody-positive pregnancies.

    Saleh ZF, Somers EC, Romero VC, Marder W

    American journal of obstetrics and gynecology 2026; (234(1)):7-20 doi:10.1016/j.ajog.2025.09.002.

    PMID: 40930382
  10. 10

    Hydroxychloroquine in lupus or rheumatoid arthritis pregnancy and risk of major congenital malformations: a population-based cohort study.

    Nguyen NV, Svenungsson E, Dominicus A, et al.

    Rheumatology (Oxford, England) 2025; (64(1)):117-125 doi:10.1093/rheumatology/keae168.

    PMID: 38479815
  11. 11

    Systemic lupus erythematosus in pregnancy: high risk, high reward.

    Do SC, Druzin ML

    Current opinion in obstetrics & gynecology 2019; (31(2)):120-126 doi:10.1097/GCO.0000000000000528.

    PMID: 30676534
  12. 12

    A rare case of myocardial bridging as a cause of complete heart block: A diagnostic challenge.

    Fathallah I, Qatza A, Al-Talep A, et al.

    Radiology case reports 2025; (20(4)):1882-1887 doi:10.1016/j.radcr.2025.01.003.

    PMID: 39897757
  13. 13

    Neonatal lupus erythematosus - practical guidelines.

    Derdulska JM, Rudnicka L, Szykut-Badaczewska A, et al.

    Journal of perinatal medicine 2021; (49(5)):529-538 doi:10.1515/jpm-2020-0543.

    PMID: 33470961
  14. 14

    [Clinical characterization of patients with complete fetal atrioventricular block].

    Muralles-Castillo FA

    Archivos de cardiologia de Mexico 2024; doi:10.24875/ACM.24000049.

    PMID: 39536270
  15. 15

    The prevention, screening and treatment of congenital heart block from neonatal lupus: a survey of provider practices.

    Clowse MEB, Eudy AM, Kiernan E, et al.

    Rheumatology (Oxford, England) 2018; (57(suppl_5)):v9-v17 doi:10.1093/rheumatology/key141.

    PMID: 30137589
  16. 16

    Fluorinated steroids are not superior to any treatment to ameliorate the outcome of autoimmune mediated congenital heart block: a systematic review of the literature and meta-analysis.

    Hoxha A, Mattia E, Zanetti A, et al.

    Clinical and experimental rheumatology 2020; (38(4)):783-791.

    PMID: 32573408
  17. 17

    Assessment of fluorinated steroids to avert progression and mortality in anti-SSA/Ro-associated cardiac injury limited to the fetal conduction system.

    Izmirly PM, Saxena A, Sahl SK, et al.

    Annals of the rheumatic diseases 2016; (75(6)):1161-5 doi:10.1136/annrheumdis-2015-208311.

    PMID: 26835701

This page provides educational information about prenatal monitoring and treatments for congenital heart block. It does not replace professional medical advice. Always consult your maternal-fetal medicine specialist or obstetrician for your specific pregnancy care.

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