Every year, more than 200,000 African children are born with sickle-cell anemia -- around 150,000 of those in Nigeria.

At the Lagos University Teaching Hospital (LUTH), rows of young women line up inside the antenatal clinic. Many of them suffer from sickle-cell anemia, the world's most common hereditary blood disorder. They are here to see Dr Bosede Afolabi, a specialist practitioner who has dedicated much of her working life to studying the disease and how it affects pregnant women and their babies.

"We have the highest number of people suffering from sickle-cell disease in the world," explains Afolabi, an associate professor of obstetrics and gynecology who consults twice a week at LUTH.

Her mission is to use her knowledge to cut maternal mortality in Nigeria. Around one in four people in the West African country carries the sickle cell gene -- around 40 million people -- and virtually everyone has lost a relative or a close friend to the disease.

Sickle-cell anemia, which is also referred to as SS disease, is an inherited form of anemia -- a condition in which there aren't enough healthy red blood cells to carry adequate oxygen throughout the body.

Normally, red blood cells are flexible and round, moving easily through blood vessels. In sickle-cell anemia, however, the red blood cells become rigid and sticky and are shaped like sickles or crescent moons. These irregularly shaped cells can get stuck in small blood vessels, which can slow or block blood flow and oxygen to parts of the body.

Poor blood oxygen levels and blood vessel blockages can result in chronic acute pain syndromes, severe bacterial infections and tissue death, according to the World Health Organization. The sickle-cell trait has a partial protective effect against malaria, and this could explain its high prevalence levels in tropical parts of Africa.

For a child to be born with the condition, both parents must carry a sickle-cell gene, which is passed from one generation to the next. "If somebody with a trait marries another person with a trait, there's an one in four chance that the offspring will have SS," explains Afolabi.

At LUTH, she sees patients and passes on her knowledge to duty registrars as well as conducting key research on a disease that affects both women and children before, during and after birth.

"Very few people are doing research in pregnancy in SS women," says Afolabi. "What I'm doing is adding to the body of knowledge that exists and putting on some more, especially since physiological research in pregnancy is not very common.