ANTIPHOSPHOLIPID ANTIBODIES SCREENING IN WOMEN PRESENTING WITH PRETERM DELIVERY DUE TO PREECLAMPSIA OR PLACENTAL INSUFFICIENCY – IS IT WORTH IT?

Problem statement:

Preterm delivery due to preeclampsia or placental insufficiency (PREPI) is one of the clinical criteria for obstetric antiphospholipid syndrome (APS). Although previous case-control studies reported higher prevalence of antiphospholipid antibodies (aPL) in these women (up to 17.8% of cases), due to insufficient evidence, current guidelines give conflicting recommendations regarding testing for aPL in this setting.

We aimed to assess the proportion of women with positive aPL when screening was performed in these circumstances.

Methods:

A retrospective observational study was conducted. Data from deliveries occurring up to 34 weeks (January/2018 to March/2021), due to PREPI, were retrieved. Previous known APS were excluded (Sapporo’s criteria). Postnatal weight percentile was calculated using the Hadlock formula. Statistical analysis was performed using SPSS® 27.0.

Results:

Premature labor due to PREPI occurred in 34 women (mean - 31 weeks of gestation). Preeclampsia was recognized in 15 cases (44.1%), 17 women (50.0%) had fetal growth restriction and 2 cases (5.9%) had other features of placental insufficiency. Most women were nulliparous (67.6%), 26.5% had one previous delivery and 5.8% were multiparous. None had a previous history of spontaneous abortions or fetal death.

Postpartum obstetric consultation occurred in 25 cases (73.5%). Screening for aPL was accomplished in 22 women, of which 7 (20.6%) had a result that was considered positive [4 lupus anticoagulant (LA), 2 anticardiolipin antibody (AC) and 1 anti- 2 glycoprotein-I antibody (AB2)]. All women with a positive first test, repeated it 12 weeks after, with 4 cases (18% of the tested women) presenting a persistently positive result (2 LA, 1 AC and 1 AB2).

Conclusion:

Despite the small sample size, our results show a high proportion of positive aPL in women presenting with PREPI. This is in accordance with previous studies.

Our work confirms the importance of establishing consistent recommendations regarding the criteria for aPL testing in PREPI and maintaining consequent and appropriate follow-up.

Larger studies would be of the upmost importance to better establish the importance of screening these women, given the potential impact in future pregnancies and/or clinical settings with increased thromboembolic risk.