Association Between Novel Antiphospholipid Antibodies and Adverse Pregnancy Outcomes

( Obstet Gynecol . 2025;145(1):55-64. doi: 10.1097/AOG.0000000000005729) Antiphospholipid syndrome is a rare but serious autoimmune condition that is defined as macrovascular and microvascular thrombosis or other obstetric complications with the presence of sustained antiphospholipid antibodies (aPL); obstetric antiphospholipid syndrome is defined as 3 or more pregnancy losses before 10 weeks’ gestation, fetal death at or after 10 weeks’ gestation, and delivery before 34 weeks’ gestation that can be attributed to preeclampsia or placental insufficiency in the presence of aPL. Previous literature has established that lupus anticoagulant (LA) is significantly predictive of adverse pregnancy outcomes, and new evidence is increasing showing that antibodies to domain 1 of β2-glycoprotein I (aD1), as well as phophatidylserine-prothrombin (aPS/PT), may be part of the mechanism for this correlation. There are currently no studies examining this possibility, and this study was designed to assess the association of aD1 and aPS/PT with adverse pregnancy outcomes in an at-risk population as well as assess the relationship between aD1, aPS/PT, and LA.