How safe are monoclonal antibody treatments for pregnant women?

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8321301/#:~:text=Increasingly%2C%20pregnant%20patients%20with%20inflammatory,abnormalities%20in%20the%20exposed%20infant

As we review this article, let us not forget that monoclonal antibodies were also used as treatment for covid in pregnant women.

“Most monoclonal antibody biologics readily cross the placenta, leading to concerns regarding their use during pregnancy and their impact on the fetus and infant, and historical avoidance of their use during pregnancy. However, the last decade has seen a shift in disease management toward tight disease control in pregnant patients and a goal of improving both maternal and fetal outcomes. Achieving clinical remission is recognized as one of the best predictors of favourable pregnancy outcomes, and a stable disease course, especially in the 6 months before conception, has been associated with improved maternal and fetal outcomes. This has resulted in an increased use of biologics before conception, during pregnancy and postpartum, with treat-to-target objectives varying for each disease.” Ok, so this was published in 2021, when monoclonal antibody use for covid was very prevalent. My question is this: if we know monoclonals cross the placenta, why did we suddenly decide over the last 10 years (and during covid) that they were safe to “optimize fetal outcomes”?

• Increasingly, pregnant patients with inflammatory or autoimmune diseases use monoclonal antibody biologics before conception, during pregnancy and while breastfeeding.

• A minority of biologics may lead to immunological and hematological abnormalities in the exposed infant.

• For infants exposed to biologics, most clinical guidelines recommend avoiding live vaccines in the first 6–12 months of life, but emerging evidence suggests that the live rotavirus vaccine may be provided safely to exposed infants if normal immune function can be documented.

Read the bolded points above: “may” lead to immunological and hematological abnormalities in infants. “Most” clinical guidelines recommend AVOIDING live vaccines for the first YEAR of life IF the infant was exposed to biologics in utero. Hmmmm. Are we doing that? How many infants do not get vaccinated during the first year because mom used a biologic during pregnancy?!?! I am guessing very few do not get vaccinated.

Check this out: The highest rate of transfer occurs after 36 weeks of gestation^, and with the following IgG subclass order of transfer efficiency: IgG1 > IgG4 > IgG3 > IgG2. IgG4 is the SECOND highest transferred antibody from mom to the fetus. Much like the placenta transfer article we discussed last week, this one also states “Consistent with studies on maternal–fetal transfer of antibodies, biologic drug levels at birth can often be higher in the infant than the mother. Infliximab levels have been reported to be twofold higher at birth in the infant than in the mother, but are generally undetectable by 3–7 months of age. Infant adalimumab levels are typically 1–1.5 times higher than maternal levels at birth, with most studies showing undetectable levels by 3–5 months of age.

Are we really going to say that these biologics and monoclonal antibodies are safe for use in pregnant women? Are they really safe for the fetus? Do we REALLY delay vaccines for a year in babies born to moms who used monoclonal antibodies during pregnancy? Or who were treated with monoclonals during covid?

This smells fishy. What are the long term effects of monoclonal fetal exposure? What does the use of vaccines in the first year of life in a fetus exposed to monoclonals do?