FAMILY MEDICINE® COLUMN
By John C. Wolf, D.O.
Associate Professor of Family Medicine®
Ohio University College of Osteopathic Medicine

PREGNANT WOMAN'S RUPTURED DISK NOT LIKELY TO CAUSE PERMANENT DISABILITY

Question: My wife has had serious back pain from a ruptured disk. Now she has become pregnant, and we need to know if this pregnancy will make her back pain worse. We need to know soon so that we can terminate the pregnancy if this back problem and the pregnancy together will make her disabled.

Answer: Let me review for you and my other readers how a ruptured disk (also known as a slipped disk, herniated disk, or herniated nucleus pulposus) can cause back pain. As I suspect you know, the nerves of the spinal cord are surrounded and protected by a series of interlocking bones called the vertebrae. Each of these vertebra, in addition to having an opening for the passage of the spinal nerves, has disks that both support and cushion it in relation to the vertebrae above and below. The disk is constructed of a tough outer layer and a softer gelatinous inner filling called the nucleus pulposus. This is similar to the construction of a jelly-filled doughnut.

Mechanical stress on a disk can cause a tear in the disk's outer layers. As a result, the nucleus pulposus bulges through the tear in a manner similar to what happens when you bite into a doughnut and the jelly squirts out a gash on the other side. Because of the mechanical forces on a disk, the bulge always occurs toward the spinal canal. Thus the ruptured gelatinous material (and swollen adjacent tissue) press on the nerves at that level of the spine. This often causes back pain as well as pain in the areas served by the nerves. For instance, a herniated disk in the low back typically causes pain not only in the back but also in the buttocks and legs.

Pregnancy causes considerable stress on the back. Ask any mother if you don't believe me. Most women gain at least 30 pounds with a pregnancy, and the back must carry this additional load. In addition, the majority of the weight is on the front side of the body. This requires leaning backward to keep the center of gravity over the feet. These changes result in the characteristic gait, or walking pattern, of a woman who is about to deliver.

It is uncommon for a herniated disk to result in a permanent disability. Most who have this condition have one or more temporary periods where their back pain limits their activity. Most often, non-surgical treatment consisting of medicine, exercise, and decreased demand upon the back produces healing. In some cases surgery may be necessary to remove the herniated disk material that is pressing on the nerves. Of the select group who need surgery, a small segment require repeat surgery. Only about 2 to 3 percent of these repeat surgery types become permanently disabled from their back problems. That represents a very small sub-group of all of those with herniated disks.

Fortunately, it is very unlikely that your wife's pregnancy will affect the prospects of recovery from her disk problem. This means that you will not have to face the question of pregnancy termination, which is one of the toughest moral/ethical decisions in our society today. Placed in perspective, then, your wife's herniated disk is a painful annoyance that will not overshadow the great joys before you as you prepare for parenthood.

Family Medicine® is a weekly column. To submit questions, write to John C. Wolf, D.O., Ohio University College of Osteopathic Medicine, Grosvenor Hall, Athens, Ohio 45701.