If OI is moderate or severe, health care providers usually diagnose it during prenatal ultrasound at 18 to 24 weeks of pregnancy.
If a parent or sibling has OI, a health care provider can test the DNA of the fetus for the presence of an OI mutation. In this case, a health care provider obtains a sample of fetal cells by chorionic villus (pronounced KOHR-ee-on-ik VILL-uhs) sampling (CVS) or amniocentesis (pronounced am-nee-oh-sen-TEE-sis). The fetal cells can also be tested for the presence of abnormal collagen.
For amniocentesis, a health care provider takes a small amount of fluid from the sac surrounding the fetus for testing. He or she takes the sample by inserting a thin needle into the uterus through the abdomen. For CVS, a health care provider uses a similar procedure to take a sample of tissue from the placenta for testing.
If OI is not detected prenatally, parents or a health care provider may notice symptoms in an infant or child. The health care provider may perform the following:
- Physical exam, which includes:
- Measuring the length of limbs
- Measuring the head circumference
- Examining the eyes and teeth
- Examining the spine and rib cage
- Personal and family medical history, which include questions about:
- Broken bones
- Hearing loss
- Brittle teeth
- Adult height
- Racial background
- Whether close relatives have had children together
- Bone density test
- Bone biopsy, in some cases
Health care providers may send blood or skin samples to a lab for collagen or genetic testing. These tests usually confirm whether a person has OI.1,2,3