Answer:
The pregnant woman and the father of the fetus.
Explanation:
A fetus cannot answer for itself only if it agrees to participate in a research project, therefore, considering that the fetus' parents are healthy and have perfect psychological conditions of discernment, they will be responsible for giving their consent. participation of the fetus in the research project. Based on this, in the case set out in the question, the investigator must obtain consent from the pregnant woman and the father of the fetus.