Pregnant women should not give up daily coffee, because not only do they not endanger the health of the baby, but they can also be protected from various diseases.

But experts warn that expectant mothers should never consume more than 200mg of caffeine a day, which is equivalent to two cups of coffee or two teas and a can of cola.

Researchers at the University of Pennsylvania looked at 2,529 pregnant women who participated in a study between 2009 and 2013. At the start of the study, each woman reported how much caffeine they drank per day.

Caffeine was also measured in blood tests at 10 and 13 weeks of pregnancy. Next, the team looked at diagnoses of a variety of illnesses that could occur during pregnancy. They found that drinking 100 mg of coffee a day, about one cup of coffee, reduced the risk of developing diabetes by up to 47 percent.

Gestational diabetes occurs when a pregnant mother has high blood sugar that usually disappears after delivery. It is treatable and normally mothers have healthy babies.

However, because of it, expectant mothers may be at risk of developing type 2 diabetes in the future, a chronic condition that needs lifelong management with diet, exercise and sometimes medication.

It can also cause problems with the delivery of the baby. Mothers can go into labor prematurely, they can give birth by caesarean section because the baby is growing too much or because there is too much fluid in the uterus.

The baby may also be born with jaundice, a liver problem that causes yellowing of the skin and eyes, requiring hospital treatment. In very rare cases, gestational diabetes can cause the baby to be stillborn.

"Our findings may offer some reassurance to women who are already consuming low to moderate levels of caffeine," said Dr. Stefanie Hinkle, an assistant professor of epidemiology at Penn and lead author of the study.

However, she added: "It is not advised that women who do not drink alcohol start drinking caffeinated beverages in order to reduce the risk of gestational diabetes."

If caffeine is consumed at high levels, research has shown that it can cause miscarriage or the baby is born under normal weight.

Panorama