A large proportion of patients with systemic lupus erythematosus (SLE) are women of reproductive age. Their fetal outcome is undoubtedly less favourable than in healthy women. Although there is no evidence of an increase in congenital anomalies, increased frequencies of miscarriage, stillbirth, growth retardation, and preterm delivery are recognized. It mainly depends on the compromise of uteroplacental circulation such as renal disease, hypertension and thrombopoietic action of antiphos-pholipid antibody. Besides a small proportion of the newborn infants get a neonatal lupus sydrome, the most serious component being congenital heart block. This complication occurs almost exclusively in the offspring of women with anti-Ro/SSA antibodies. In order to find out the effect on fetus and newborn infants born to SLE mother, we reviewed clinical records of 11 infants born to 9 mothers with confirmed or suspected SLE at Seoul National University Hospital between June 1981 and May 1991. The results obtained were as follows: 1) Seven mothers among 9 were confirmed as SLE and 2 were suspected. 2) There were 6 spontaneous abortions (20.0%) and 5 stillbirths (16.7%) in 5 mothers among thirty pregnancies of 9 mothers. 3) Among 11 newborns, 4 (36.4%) were premature and 2 (18.2%) were small for gestational age. 4) Six mothers had proteinuria, over 4+, in Albustix. Four of these, including 3 preeclampsia mothers, delivered preterm babies. Two of premature babies were born through Cesarean section due to fetal distress and expired of hyaline membrane disease and its complications. The other 2 had thrombocytopenia and leukocytopenia at birth. One of these had intracranial hemorrhage at birth and seizure. 5) There were 2 mothers who had positive anticardiolipin antibody with SLE or without SLE. One with SLE was continuing positivity of the antibody during pregnancy and delivered premature baby who expired of HMD and PDA. The other who had seroconversion to negativity during the first trimester developed intermittently sinus bradycardia without apnea for 3 days. 6) Two of 11 newborns had only talipes equinovarus. 7) One mother who had anti-Ro/SSA antibody delivered monozygotic twin. The first baby was neonatal lupus erythematosus with complete heart block and skin pigmentation. All of them were suspected to right aortic arch and Kommerell's diverticulum on echocardiogram. As the above results, SLE mothers can cause serious effect on fetus and newborn when accompanied with active renal impairment, hypertension and positive antiphospholipid antibody. So we should treat mother with SLE even during pregnancy and it may give better outcome to mother and fetus. It will be useful for diagnosis and treatment of neonatal lupus erythematosus that the prenatal test for anti-Ro/SSA antibody, fetal monitoring, fetal echocardiogram and postnatal close observation for skin are taken.