If your baby is at the funeral home or the hospital, you can ask the funeral director to take them to the venue of the funeral. If you do not want a hearse, you could ask that your baby be transported in an ordinary car. Some funeral directors have cars that are adapted to carry a small coffin and have space for the family.
You will also have the option of collecting your baby and taking them to the ceremony yourself. If you are using a taxi, make sure that they agree in advance to transport a coffin. If your baby is at home, you can take them directly to the funeral.