The baby slips in the tub and Mum or Dad grabs their arm, where a bruise soon shows up.
This can be unsettling, says Dr Carmen Escuriola-Ettingshausen, director of Germany's Rhein Main Haemophilia Centre (HZRM). "First-time parents in particular blame themselves, thinking they may have grasped their child too firmly."
The bruise could be a sign of haemophilia, a rare bleeding disorder in which the blood fails to clot properly because it doesn't have enough blood-clotting proteins, called clotting factors. It's almost always caused by certain inherited gene changes and predominantly affects males.
Aside from bruising easily, symptoms include bleeding for a long time after an injury, surgery or dental work, frequent nosebleeds and painful, swollen joints from internal bleeding.
People with serious haemophilia often show symptoms in infancy, while milder cases may go undetected until later in life.
Along with the three main severity levels – mild, moderate or severe – the disorder is classified into three main types depending on the clotting factor that's deficient.
Haemophilia A (clotting factor 8) is by far the most common type, and haemophilia C (clotting factor 11) is extremely rare. The Montreal-based World Federation of Hemophilia estimates a global prevalence of 17.1 cases of type A per 100,000 males, and 3.8 cases of type B (clotting factor 9).
What possible signs of haemophilia should parents be aware of?
The first thing to know is that "there are extremely heavy and less heavy bleeders," says Escuriola-Ettingshausen. Haemophilia "usually becomes noticeable when children move about – when they start to turn around, crawl or learn to walk."
Having an unusually large number of bruises is a red flag.
A poorly healing navel after birth or scratches that constantly bleed could be early warning signs as well, she says.
If you're concerned your child may have haemophilia, a medical examination is advisable. Their blood will be tested for a deficiency of clotting factor 8 or 9. Early detection is important, because left untreated, it can lead to joint damage or dangerous bleeding into the brain after a bump on the head.
Once diagnosed, the disorder is highly treatable, mainly by intravenous supplementation of the deficient clotting factor. This allows the child to grow up nearly normally, Escuriola-Ettingshausen says, "almost as if they didn't have haemophilia." – dpa
