What are the effects of Antiphospholipid Antibody Syndrome (APAS) on newborns?

Effects of Antiphospholipid Antibody Syndrome (APAS) on Newborns

Newborns born to mothers with APAS are at increased risk for prematurity (25-35%), intrauterine growth restriction (18-21%), and thrombocytopenia, but with appropriate maternal treatment during pregnancy, the majority (85.7%) achieve live birth with generally favorable long-term outcomes. 1, 2

Primary Neonatal Complications

Prematurity and Growth Restriction

• Preterm delivery occurs in 25-35% of pregnancies with APAS, even with standard treatment using prophylactic heparin and low-dose aspirin 1
• Intrauterine growth restriction (IUGR) affects 18-21% of infants born to mothers with APAS 2, 3
• Birth weights below the 10th percentile occur in approximately 21% of cases, with dual parameter positivity (lupus anticoagulant plus anticardiolipin antibody) conferring higher risk 4
• Mean gestational age at delivery is approximately 36.7 weeks (range 25-40 weeks) in treated pregnancies 5

Hematologic Complications

• Neonatal thrombocytopenia occurs in a subset of infants, particularly when maternal platelet counts are reduced 3
• Thrombocytopenia can lead to serious complications including intracranial hemorrhage, as documented in case reports 3, 6
• The first reported case of extensive fetal intraventricular hemorrhage related to OAPS highlights the prothrombotic and hemorrhagic potential of maternal antiphospholipid antibodies affecting the fetus 6

Maternal Treatment Impact on Neonatal Outcomes

Treatment Efficacy

• Standard treatment with prophylactic heparin and low-dose aspirin dramatically improves live birth rates from 4.6% to 85.7% in women with APAS 1, 2
• Despite treatment, pregnancy loss still occurs in 25% of obstetric APS pregnancies 1
• No APAS-related malformations, thrombosis, or other antibody-related disorders were observed in a cohort of 55 newborns whose mothers received calcium heparin during pregnancy 5

Neonatal Intensive Care Requirements

• Approximately 21.8% of newborns require admission to neonatal intensive care units, with stays ranging from 2 to 120 days (mean 30.3 days) 5
• All complications requiring NICU admission were exclusively due to prematurity, not direct APAS-related pathology 5
• Mean Apgar scores at 5 minutes are reassuring at 9.6 (range 7-10) 5

Long-Term Developmental Outcomes

Neurodevelopmental Follow-up

• Long-term follow-up studies (1.3 to 5.7 years) show generally reassuring outcomes, with children developing normally without APAS-related manifestations 1, 5
• All children examined showed normal neurodevelopmental and physical findings on pediatric review 4
• No developmental abnormalities were detected on follow-up in multiple cohort studies 5, 4

Important Caveat

• Some reports suggest potential neurodevelopmental alterations in offspring of mothers with SLE and/or APS, though these findings require further confirmation before definitively linking them to maternal disease 1
• The diseases observed during follow-up periods did not differ from those of the normal pediatric population 5

Maternal Complications Affecting Neonatal Risk

Preeclampsia and Placental Insufficiency

• Preeclampsia occurs in 10-20% of APAS pregnancies, contributing to prematurity and IUGR 1, 2
• Eclampsia/HELLP syndrome rates approximate 1.0-5.0% depending on whether APS is primary or SLE-related 1
• These complications necessitate strict monitoring and timely delivery even in treated pregnancies 2

Intrauterine Fetal Demise

• Despite treatment, intrauterine fetal death occurs in approximately 4.7-9.1% of cases 2, 3
• Abruptio placentae complicates approximately 7.1% of pregnancies 2

Clinical Monitoring Recommendations

Antenatal Surveillance

• Women with severe or early preeclampsia and/or history of pregnancy loss should be evaluated for OAPS and carefully monitored throughout pregnancy 6
• Serial fetal monitoring is essential given the 25-35% prematurity rate and 18-21% IUGR rate 1, 2

Neonatal Evaluation

• Clinical examination immediately after delivery with neonatological check-up within 24 hours is standard practice 5
• Platelet count monitoring in neonates is warranted, especially when maternal thrombocytopenia is present 3
• Cranial imaging should be considered in cases of idiopathic fetal hemorrhage to evaluate for OAPS-related complications 6

Key Clinical Pitfalls

• Do not assume that maternal treatment eliminates all neonatal risk—complications like preeclampsia and IUGR persist despite optimal anticoagulation 1, 2
• Do not overlook the possibility of neonatal thrombocytopenia and its hemorrhagic complications, even though thrombosis is the hallmark of maternal disease 3, 6
• Do not attribute all prematurity-related complications to APAS itself—most NICU admissions reflect prematurity rather than direct antibody effects 5