Objective To explore the relationship between the stress during pregnancy and the NMDA-induced spasm. MethodsThe pregnant rats were divided into two groups: pregnant control group(PC group)and pregnatal stress group(PS group). The rats in PS group were forced to swim in cold water of 4℃ for five minutes. Pups of the two groups were injected NMDA 7mg/kg intraperitoneally on postnatal day 13 to induced infantile spasm-like attacks. Then the clinical behavior of pups of the two groups were observed and recorded. The ultrastructure of mitochondria was detected with scanning electron and appearance of neurons was observed with HE staining. NMDA receptor and its subuniforms (NR2A, NR2B) in hippocampus, cerebral cortex, hypothalamus and raphe nucleus of brainstem were estimated by immunohistochemistry. Results The average score of pups in PS group is higher than in PC group(7.84 ±1.01 vs 5.90 ± 1.12). There were swelling neurons and no cytonecrosis in hippocampuss of both two groups. The uhrastructure of mitochondria in hippocampuss and raphe nucleus of brainstem showed great changes in pups of PS group as membrane in mitochondria of pups in PS group. NR1, NR2A and NR2B distributed mainly on the membrane and also in cytoplasm and cellular nucleus. The NR1 expressions in hippocampus, cerebral cortex, hypothalamus and raphe nucleus in pups of PS group were elevated than those of PC group and the P value is 0.001, 0.009, 0.015, 0.001 respectively. The NR2B expressions in hippocampus, cerebral cortex hypothalamus and raphe nucleus in pups of PS group were elevated than those of PC group and the P value is 0.004, 0.002, 0.003, 0.002 separately. NR2A expressed more in hippocampus in pups of PS group than that in PC group,but there was no difference in cerebral cortex, hypothalamus and raphe nucleus between two groups and the P value is separately 0.006,0.067, 0.7, 0.5. Conclusions The mitochondria of neurons in rat pup were hurt by maternal severe stress daring pregnancy, which made the energy metabolism of neurons changed. Maternal stress can also elevate the expression of NR1, NR2A and NR2B in cerebral cortex, brainstem and hippocampus and increase the morbidity of infantile spasm-like attacks.