the short interval pregnancies is associated with some adverse outcome of perinatal, pregnancy may poorly end up.

don't you know that having short pregnancy interval can increase the risk of sudden infant death syndrome? yes it is true.

there is an evidence showing that those babies who are born to women with a less interval pregnancy will increase the risk of preterm birth

some are just still theories like the maternal nutritional depletion hypothesis that suggests the mother to have an ample time to recover. this is done because most of those women with short interval pregnancy tends to have nutritional deficiency.