In October of last year, the journal Obstetrics and Gynecology published the results of a study that was funded by the Centers for Disease Control and Prevention. This study showed that the possibility of a fetal neural tube defect doubled with the consumption of opiate pain medications in early pregnancy, specifically in the first thirty days. The study used data from the Sloane Epidemiology Center Birth Defects Study coupled with telephone interviews, and compared the incidence of opioid use among mothers of 305 children with neural tube defects and mothers of 7,125 children without deformities. 3.9% of mothers of children with neural tube defects reported using opioid medications, compared with opioid use among 1.6% of the mothers of children without neural tube deformities.
Opiate painkillers are not the only medication associated with neural tube defects. Significant and well-known contributory factors include medications like the acne drug Accutane® or the anti-epilepsy medications valproic acid and carbamazepine, and inadequate maternal folic acid is also a predisposing factor. Because early pregnancy is a critical time for the coalescence of embryonic tissues into their ultimate form, doctors who prescribe any potentially teratogenic medication to women of childbearing age typically display an abundance of caution.
Neural tube defects are usually picked up in prenatal screening. During formation of the nervous system and epidermis, the structure known as the neural tube is open at both ends for a short period of time. While open, specific fetal substances like alpha-fetoprotein are released into the amniotic fluid. If the neural tube fails to close properly, the substances remain in the amniotic fluid and elevated levels in the mother’s serum can be used as a marker of a neural tube defect. This test is usually done between 15 and 20 weeks gestation, although the test results are most sensitive at 16 to 18 weeks. Ultrasound examination should routinely be performed during the second trimester, between week 16 and week 20, to look for deformities in the fetus. This may reveal deformities of the spine, the skull, or a reduction in movement in the fetal legs.
Neural tube defects are congenital defects that result from the failure of closure of the embryonic structure that becomes the central nervous system. Resulting neurologic deficits correlate with the level of the injury within the central nervous system, and the amount of neural tissue involved.
Three main neural tube defects are known as anencephaly, encephalocele and spina bifida. Anencephaly is characterized by the absence of the brain and the calvarium, which is the portion of the skull that covers the brain. This defect is obviously incompatible with life. Encephalocele refers to the protrusion of portions of brain tissue through the skull, and results in death or severe disability. Surgery can improve the outcome if undertaken quickly.
The most commonly seen neural tube defect is spina bifida, which is a class of defects in the bony spine, known as the vertebral column. The spine is made up of 24 bones, called vertebrae. The vertebrae protect the spinal cord by creating a bony canal through which the spinal cord travels from the brain. In spina bifida, the posterior portion of one or more vertebrae, known as the posterior arch, does not close properly, and depending upon the extent of the failure and size of the breech, the range of outcomes is widely variable.
Spina bifida occulta is both the mildest and most common type of neural tube defect, with most patients remaining asymptomatic. In spina bifida occulta, other tissues cover the bony defect and there is often no damage to the spinal cord or its roots. However, spina bifida cystica, open spina bifida, includes both menigocele and myelomeningocele, referring to protrusions of the covering of the spinal cord or of both the covering and cord itself, through the bony spinal defect. There may be coverage by skin, which results in the appearance of a cystic appearance.
Myelomeningocele results in varying degrees of disability in 99% of affected patients, depending upon the level of the spinal cord that is protruding. Multi-organ dysfunction may occur, and associated disorders include tethering of the spinal cord, hydrocephalus, and syringomyelia, a disorder that can result in motor and sensory dysfunction in the periphery.
There are many factors that are associated with failure of the neural tube to develop properly. This is not the first study that suggests an association with opioid use. It is important for all mothers to exercise all precautions during any time periods in which they might become pregnant. If, however, you do give birth to an infant with a neural tube defect, it is important to consider the potential cause and whether it was preventable. The costs of care for a surviving child with a neural tube defect can be tremendous.
If you were the victim of negligence or malpractice that resulted in a congenital neural tube deformity, you may have recourse to compensation and should contact an expert medical practice attorney at Passen & Powell. Call us at 312-527-4500.