Human IgG are excreted into milk during the first few days after birth. A 2009 case report described two mothers with common variable immunodeficiency who used IVIG 400-700 mg/kg monthly throughout pregnancy. Timing of the last dose prior to milk sampling was not provided. In day 3 colostrum samples, IgG levels were normal and high whereas IgM levels were low and normal. In day 7 milk samples, both IgG and IgM levels were normal. No adverse events were reported (12).

A 2004 retrospective study of 108 women with relapsing remitting multiple sclerosis received IVIG 0.4 g/kg daily for 5 days during the first postpartum week and then 0.4 g/kg at 6 and 12 weeks postpartum (n = 41), 0.4 g/kg daily for 5 days at 6-8 weeks' gestation and then 0.4 g/kg every 6 weeks through 12 weeks postpartum (n = 28), or no therapy (n = 39). No difference was found between gestational age of delivery, birth weight, mode of delivery, or obstetric complications. Breastfeeding continued for 3-12 weeks in 78 infants. No serious maternal or infant adverse event was reported. Postpartum relapse rates were lower in patients who received treatment (13).

A 2000 case series described 43 women with multiple sclerosis who breastfed for at least 4 weeks. IVIG 60 g was initiated within 3 days of delivery and followed by 10 g monthly. The only adverse event observed was a rash in an infant 1 day after the mother received IVIG (14).

Immune globulin IV (IGIV) is a solution of immunoglobulin, primarily immunoglobulin G (IgG), prepared from pooled plasma that, in contrast to the IM preparation, provides immediate serum concentrations of antibodies (1).

Animal Data: No animal reproduction studies have been conducted (1).

Placental Transfer: IgG administered IV was shown to cross the human placenta in significant amounts only if the gestational age was >32 weeks (2). Placental transfer was also a function of dose, as well as gestational age. Four subclasses of IgG and two different antibodies in the preparation also crossed to the fetus in a similar manner (2). Others have found that the placental transfer of exogenous IgG depends on the dose and duration of treatment and, possibly, on the method of IgG preparation (3).

Human Data: A 1988 review of IGIV summarized the clinical indications for the product in pregnancy (4). The indications included hypogammaglobulinemia such as common variable immunodeficiency, autoimmune diseases such as chronic immune thrombocytopenic purpura, and alloimmune disorders such as severe Rh-immunization disease and alloimmune thrombocytopenia. Recent reports have described the use of IGIV for the prevention of intracranial hemorrhage in fetal alloimmune thrombocytopenia (5,6), recurrent abortions caused by antiphospholipid antibodies (7,8), neonatal congenital heart block caused by maternal antibodies to Ro (SS-A) and La (SS-B) autoantigens (9), and severe isoimmunization with either Rh or Kell antibodies (10). No adverse effects were observed in the fetus or newborns in any of the above reports, but caution has been advised in its use to prevent spontaneous abortion (11).