For exposure-response array data display purposes, the following results were coded (control and no effect findings were coded as "0", treatment-related increases were coded as "1", and treatment-related decreases were coded as "-1".

"In the 30 mg/kg NBP2 dose group, all pups except for one were stillborn. In the remaining dose groups (≤10 mg/kg) there was no effect J.M. Conley et al. Environment International 160 (2022) 107056 5 of treatment on birthweight (Fig. 1A). In the 10 mg/kg NBP2 dose group there was no stillbirth but by 14:00 EST on PND1 there was 47% mortality and remaining live pups were significantly smaller than control (13% reduction, p = 0.03, Table S1). Histopathological evaluation of newborn pup liver reported significantly reduced hepatic glycogen accumulation scores for animals exposed to ≥ 10 mg/kg NBP2 (Figure S2) and clinical chemistry identified significantly reduced serum triglycerides (ANOVA p = 0.0066) with ~50% reductions at 3 mg/kg (p = 0.0016) and 10 mg/kg (p = 0.0061) (Table 1; no serum collected in 30 mg/kg dose group) indicating metabolic alterations associated with prenatal NBP2 exposure.

At 09:20 EST on PND1 one dam in the 3 mg/kg group had not started delivering and lost 17.3 g BW from PND0 and was euthanized by decapitation and found to have 10 dead fetuses in the uterus. By PND2 in the 10 mg/kg group, half of the litters (2/4 litters) had 100% pup mortality and 1 litter had 87.5% mortality with only a single live pup remaining. Mean BW of live pups on PND2 was significantly reduced (p = 0.02) by 20% compared to controls at 10 mg/kg NBP2 (Table S1). There was no effect on pup bodyweight, absolute liver weight, or relative liver weight in the 0.3–3 mg/kg dose groups compared to controls (only a single pup liver weight was recorded at 10 mg/kg due to low surviving pup numbers; Table S1, Fig. 1B). Overall, on PND2 pup survival and post-implantation survival were significantly reduced at 10 and 30 mg/kg compared to controls (Fig. 1C, Table S1).

By PND13 only one litter at 10 mg/kg NBP2 had live pups remaining (25% within litter mortality; 81% dose level mortality). There was no effect of treatment on nipple retention or body weight in male or female pups on PND13 (Table S1). Similarly, at weaning there was no effect of treatment on male or female body weight compared to controls (Table S1). There was no effect of treatment on age at vaginal opening, bodyweight at VO, or bodyweight on PND38 in females (Table S1). In males, there was no effect of treatment on age at PPS, bodyweight at PPS, or bodyweight on PND45 (Table S1)."

F1 Male and Female Sprague-Dawley Rats exposed GD8-PND2