Low incidence of intrauterine growth restriction in pregnant patients with systemic lupus erythematosus taking hydroxychloroquine

Systemic lupus erythematosus (SLE) preferentially affects women of childbearing age. Miscarriages or fetal death, intrauterine growth restriction (IUGR), preterm delivery, preeclampsia and disease flares complicate pregnancy in SLE patients. Treatment is challenging due to the need to prevent disease exacerbations and limit obstetrical complications, while showing an acceptable safety profile for both the mother and the fetus. We collected data from 74 pregnancies in 53 SLE patients prospectively followed in a dedicated ‘Pregnancy at risk’ outpatient clinic from 2003 to 2019. Out of 74, 45 pregnancies patients were treated with hydroxychloroquine (HCQ). Mothers under HCQ therapy (HCQ+ patients) and those who did not receive HCQ (HCQ−) were homogeneous in terms of age and comorbidities. Disease activity prior to conception was slightly higher in HCQ+ patients. No significant difference was observed in terms of obstetrical history. In patients achieving a viable pregnancy, the rate of IUGR (4/39, 10% in HCQ+ vs 8/25, 32%, in HCQ− patients, p <.05) was significantly lower in HCQ+ patients. Conversely, HCQ+ patients displayed a significantly longer time to delivery (37.8 ± 1.72 vs. 36.3 ± 4.11 in HCQ− patients, p <.05). HCQ is safe in pregnant patients with SLE and protects against obstetrical complications.