Women are advised to give up smoking while pregnant, as it can cause low birth weight, and have a negative effect on a child's development.
Now, a new study out of England suggests working past the 8th month of pregnancy can pose similar risks - risks just like smoking.
Katherine Kohari is a doctor at Mount Sinai Medical Center. At nine months pregnant, she is still working, but is ready to give birth any day.
However, a new study by researchers at the University of Essex in England suggests that working up until your baby's due date can have the same effect on newborns as smoking during pregnancy. It may cause low birth weight, which raises the risk of poor health and delayed development in newborns.
Dr. Joanne Stone, a specialist in high-risk pregnancies, who was not involved in the research, argues that smoking is a bad habit. She says that working through pregnancy is something a woman may have to do.
"For many women it is not a choice, and they shouldn't feel like they're putting their child a risk by continuing to work," Dr. Stone says.
In some pregnancies, working through the ninth month may not be causing low birth rates, but rather an underlying medical condition could be the issue.
"If someone works through the ninth month, and they're developing high blood pressure, or have some other complication that might show up later, that might be the reason for the impact we're seeing later in pregnancy," Dr. Stone adds.
The study finds that babies of mothers who worked through the ninth month were half a pound smaller on average than infants whose mothers quit work between 6 months and 8 months.
Katherine Kohari is expecting a baby girl. She says that tests so far show that her baby is developing normally.