This case report describes the effects of bimonthly long-acting injectable cabotegravir (CAB)/RPV before and throughout pregnancy. CAB concentrations were comparable to those in nonpregnant individuals; RPV concentrations were 70%-75% lower. No virologic failure or vertical transmission occurred. Despite placental transfer, no congenital malformations were noted. Bimonthly long-acting injectable CAB/RPV may not be suitable for pregnant women, and monitoring of exposed infants is warranted.