False positivity of prenatal Down's syndrome and neural-tube tests in SLE

False positivity of prenatal Down’s syndrome and neural-tube tests in SLE Sir—Combination of maternal age plus three biochemical markers, maternal serum fetoprotein (AFP), human chorionic gonadotropin and unconjugated oestriol (uE3), is thought an effective screening protocol for the antenatal detection of fetal Down’s syndrome.1 Sensitivity is 60% and falsepositive rate 5%, at a risk level of one in 250 livebirths or more. Separately, AFP testing is used for detection of neural-tube defects. Some work has shown that AFP increase, in addition to cancer, liver diseases, acute bleeding anaemia, renal agenesis, multiple gestation, and fetal demise,2 can be associated also with rheumatoid arthritis,3 systemic lupus erythematosus (SLE) with and without pregnancy, and other connective-tissue diseases such as underlying placental pathology and fetal damage,4,5 or as an effect of the disease itself. Abnormal maternal serum AFP concentrations with no increase in neural-tube or other birth defects have been associated with higher prednisone dose, preterm delivery, and antibodies to cardiolipin (aCL).4 We have found an increased risk for Down’s syndrome (one per 255) detected by the Wald and colleagues’ screening protocol,1 and of fetal neuraltube defects (one per 897), in a primipara SLE patient aged 28 years on low-dose steroids during pregnancy. Multiple of median for unaffected pregnancies of the same gestational age was 1·71 for AFP, 4·14 for human chorionic gonadotropin, and 0·43 for uE3, respectively. By contrast, normal amniocentesis without chromosome abnormalities, normal ultrasound fetal biometric indices during pregnancy, and healthy babies born at week 40 was seen. Patients, obstetricians, and, overall, physicians must be aware of dual false positivity in SLE pregnancy for Down’s syndrome and neural-tube defects. *Giovanni La Montagna, Antonietta Baruffo, Giovanni Buono, Rosella Tirri Divsione di Reumatologia, Seconda Università degli Studi di Napoli, via Pansini 5, 80131 Napoli, Italy 1 Wald NJ, Cuckle HS, Densem JW, et al. Maternal serum screening for Down’s syndrome in early pregnancy. BMJ 1988; 297: 883–87. 2 Thomas RL, Blakemore KJ. Evaluation of elevation in maternal serum alpha fetoprotein: a review. Obstet Gynecol Surv 1990; 45: 269–83. 3 Andrews LG, Souma JA. Elevated serum alpha-fetoprotein in a pregnant woman with