The newborns had a 67% and 133% greater risk of being classified as very and extremely low birth weight, respectively.
Cases are even rising in countries such as Costa Rica and Mexico that typically see dengue rises in the second half of the year.
The territory last declared an emergency owing to dengue in 2012.
Dengue cases in the Americas so far this year are outpacing last year's record activity.
The step frees up more resources for the dengue outbreak, which has sickened more than 31,000 people so far.
In hard-hit Brazil, the health ministry has asked the Fiocruz Institute to double its dengue test production.
Vector-borne illnesses have doubled over the past two decades, as the number of pathogens grows and affected areas expand.
In Brazil, Amazonas state is the hot spot, but health officials are also investigating cases in Acre and Roraima states.
VE was 80.1% for participants aged 2 to 6 years.
At tomorrow's hearing, Senators will hear from long-COVID patients, doctors, and researchers.