This study examined the potential association of maternal serum levels of o,p′-DDT and p,p′-DDE with gestation time and with anthropometric measurements and thyroid-stimulating hormone (TSH) levels of newborns in a Bolivian birth cohort. Two hundred mothers were consecutively recruited between January and March 2013 at the “Hospital de la Mujer Dr. Percy Boland” in Santa Cruz de la Sierra. Potential confounders were derived from an ad hoc questionnaire. o,p′-DDT and p,p′-DDE were quantified in cord serum by high-resolution gas chromatography coupled with mass spectrometry. Multivariable linear regression analyses were performed, with POP concentrations as independent variables and log-transformed newborn birth outcomes (newborn weight, gestational age, head circumference, birth height, ponderal index, and TSH levels) as dependent variables. o,p′-DDT was detected in 82.5% of samples at median concentration of 0.22 ng/mL and p,p′-DDE in 86.5% of samples at median concentration of 1.01 ng/mL. Opposite associations with birth weight were found for p,p′-DDE (β=0.012, p=0.006) and o,p′-DDT (β=−0.014, p=0.039), and these associations were stronger when both chemicals were entered in the same model. p,p′-DDE was negatively associated with gestation time (β=−0.004, p=0.012), and o,p′-DDT was borderline negatively associated with newborn head circumference (β=−0.004, p=0.054). We observed no relevant changes in the magnitude of the coefficients or in statistical significance after adjustment for newborn TSH levels. This study indicates a possible impact of prenatal exposure to o,p′-DDT and p,p′-DDE on newborn anthropometric measurements in a population showing evidence of recent exposure to the pesticide DDT.