Introduction: Anti-Ro/SSA and anti-La/SSB antibodies are associated with neonatal lupus and congenital heart block. Controversial results regarding perinatal outcomes are found and less is known about aneuploidy screening. The hypothesis is that the presence of anti-Ro and/or anti-La antibodies influences the levels of PAPP-A and ß-HCG, thus interfering in the calculation of risk of aneuploidies.
Material and methods: Fifty-five anti-Ro/SSA positive pregnant women were included. The demographic characteristics and laboratory variables were studied. Data concerning chromosomopaties screening were also recorded.
Results: PAPP-A and β-HCG levels were calculated (as well as NT and CRL) and compared with a healthy cohort of 12971 pregnant women. PAPP-A levels in mg/mL were lower significatively. In anti-La/SS-B cohort, significant differences were found in PAPP-A in mg/mL and in MoM. Combined risks for Down syndrome (DS) in both groups were higher but the differences were due to age.
Conclusions: Serum levels of PAPP-A were significative lower but not confirmed when adjusted to MoM. This will have to be confirmed in studies with a larger number of patients and to check whether there is an impact in the calculation of DS risk or not. They could represent a group of pregnant women with significantly a higher risk of adverse perinatal outcome. Key Points • Pregnant patients with anti-Ro/SS-A ant/or anti-La/SS-B antibodies have low PAPP-A levels compared with pregnant women without antibodies. • PAPP-A levels are used in obstetrics for aneuploidies screening in the first trimester, so in these patients, there could be more false positive screening. • In these findings are verified in trials with a larger number of patients, a correction variable would have to be applied for the aneuploidies screening calculation. • Also, low PAPP-A levels are correlated with poor placentation, that is to say, more risk of miscarriages, small fetus for gestational age, and preeclampsia. This is another topic to take into consideration in this population.
Keywords: Aneuploidies screening; Anti-La/SS-B antibodies; Anti-Ro/SS-A antibodies; Pregnancy.