The court justified the lenient sentence to the "state of fury" that led to the killing of the woman.
According to the court, when the man's sister revealed to her brother that she was five-month pregnant with her former husband's child, he began chasing her in the house and pulled on her scarf to strangle her. He then put a pillow on her head and sat on it until she died.
The court considered that the woman's confession angered her brother and pushed him to act in an irrational way. The court also said the woman's "shameful behavior" deviated from the traditions of Jordanian society and harmed her family's honor.
The court acquitted the brother from the responsibility of killing the unborn baby, saying that he did not intend to kill the baby when he suffocated his sister.
In Jordan, an average of 20 women are killed in "honor killings" by male relatives each year. Men have the final say in all family matters in the largely conservative Muslim society, where many consider sex out of wedlock an indelible stain on a family's reputation.
Some women in conservative circles of society have been killed simply for dating.
Courts and authorities do not release the names of people involved in honor killing cases.
International human rights organizations have condemned honor killings in Jordan and appealed to the country's ruler, King Abdullah II, to put an end to the practice.
The government urged judges to consider honor killings equal to other homicides, punishable with up to 15 years in prison. But many judges still hand down lenient punishment to such killers.
Attempts to introduce harsher sentences for honor killings have been blocked in Jordan's parliament, where the predominantly conservative lawmakers argue that lesser penalties would lead to tolerating promiscuity.