This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Medical Illness Complicating Pregnancy, Subject name: Gynaecology & Obstetrics
Which of the following perinatal infections has the highest risk of fetal infection in the first trimester 
Select and explain. 
A. Hepatitis B virus, B. Syphillis, C. Toxoplasmosis, D. Rubella
D: Rubella
Answer: D: Rubella 
Explanation: RUBELLA Possibility of fetal infection is almost 90% when maternal transmission occurs during 1st trimester. its around 50% in the second trimester. Some of the possible effects are: Sensorineural Hearing loss, eye defects like cataracts and micro ophthalmia, Hea diseases like septal defects, Pulmonic stenosis, mental retardation. Also seen are Neonatal purpura, radiolucent bone disease & hepatospleenomegaly