But we do know that 90 percent of patients are female, and that the condition is more common in blacks (one in 250 women of childbearing age), Hispanics, and Asians, and somewhat less common in caucasians (one in 800). Typical symptoms, which follow no set pattern and can appear singly or in groups, include arthritis, rash, inflammation of the tissues that surround the heart and lungs, fever, sensitivity to light, enlarged lymph nodes, and hair loss. Up to half of patients develop kidney and neurologic disorders. Symptoms often flare up between periods of remission.

No one knows for sure whether pregnancy causes SLE to flare up. Depending on the factors they took into account, different studies have found that pregnancy can increase, decrease, or have no effect on how likely a flare-up is. But despite the lack of agreement on this issue, it's clear that many women do well during pregnancy as long as their doctors monitor them carefully for evidence of recurring symptoms.

 The symptoms of severe forms of (SLE) — high fever, hypertension, kidney failure — and some of the treatments used to combat them can seriously complicate pregnancy. Women with mild, uncomplicated lupus involving only their skin and joints often have no problems being treated during pregnancy. If anything, they're given nonsteroidal anti-inflammatory drugs (like Advil or Motrin), which are safe to take while expecting. Steroids are also safe to take in small doses, but pregnant women should avoid antimalarial drugs (such as Plaquenil), which are sometimes used to manage SLE. If you have lupus and are planning to get pregnant, consult your rheumatologist and possibly a perinatologist (a specialist in high-risk pregnancy) to better understand your specific risks.