Risk Factors for Birth Injuries

Baby's HeadA birth injury generally refers to some type of serious physical damage and injury inflicted on an otherwise healthy baby during the labor and delivery process. A birth "injury" is therefore different from a birth "defect" in that birth defects are genetically inherited abnormalities that are written into a baby's DNA. Birth defects are not caused by any sort of trauma during birth.

The reported incidence rate of birth injuries in most studies is approximately 9-12 per thousand. This means that 1 out of every 100 newborn babies will have a birth injury of some type. Birth injuries are an unpredictable occurrence in the labor and delivery room, usually in connection with some type of obstetric complication or difficult delivery process. There are, however, various condition and factors that have been linked to an increased risk of birth injury. Just because one of these conditions is present in a pregnancy does not necessarily mean that a birth injury is likely to occur. They do increase the statistical chances of that occurrence.

Size of Mom and Baby

This risk factor is very simple. During a vaginal delivery the baby has to squeeze and twist through the mother's extremely narrow birth canal all while being pushed from behind by uterine contractions. The larger the baby and/or the smaller the mother the more potentially hazardous the passage through the birth canal will be. Some babies, particularly males, grow abnormally big during pregnancy. The medical term for a baby that is overly large for its gestational age is fetal macrosomia. Any baby that exceeds 9 lbs. will be classified as macrosomic and vaginal delivery should not be attempted. This is exactly why tracking fetal growth and estimating fetal size and weight is a crucial part of good prenatal care. Fetal macrosomia is actually a very common condition, occurring in an estimated 10% of all pregnancies. The incidence rate of fetal macrosomia skyrockets to 50% for mothers with gestational diabetes. Even when fetal size and weight is normal, very small mothers may have a birth canal that is simple too small or not shaped properly creating another risk of birth injury. The medical term for this particularly condition involving the mother's birth canal is cephalopelvic disproportion (CPD).

Conditions involving the size of the mother and the baby can significantly increase the risk of all type of birth injuries during a vaginal childbirth. The reason for this increase risk is very obvious. If the mother is too small or the baby is too big, the baby is very likely to get stuck in the birth canal during delivery. One of the most common examples of this is shoulder dystocia, a complication where the baby's head comes down but its shoulder gets snagged behind the pelvic bone of the mother. A baby getting stuck in the birth canal is an extremely dangerous situation because there oxygen supply will likely be disrupted which means that could die or suffer serious brain injury if not delivered immediately. This situation is what prompts OB-GYNs to resort to using assistive tools such as obstetrical forceps or vacuum extractor pumps. Once this situation is present the baby is at risk of brain injury, head trauma from the instruments, or nerve/bone damage.

Preeclampsia

Preeclampsia is a situation that very commonly occurs towards the end of some pregnancies where acute maternal hypertension (high blood pressure) suddenly occurs and rapidly gets worse. Preeclampsia is triggered by certain abnormalities in the placenta and it is a condition that is diagnosed it approximately 9% of all pregnancies. Preeclampsia will always create an increased risk of various types of birth injuries, particularly those related to oxygen deprivation. One of the immediate reasons preeclampsia increases the chances of a birth injury is that it usually requires immediate or early delivery of the baby.

Maternal Infections

Most people do not automatically associated maternal infections with birth injuries, but mothers who have various types of infections before or during delivery have a higher birth injury occurrence rate. There are actually several related reasons for the link between maternal infection and birth injuries. For starters, an untreated maternal infection during pregnancy can sometimes affect the placental and fetal membranes. This can potentially disrupt the fetal oxygen supply which can injure the baby's developing brain and result in major birth injuries such as cerebral palsy. Infections can also complicate the actual labor and delivery process by triggering maternal fever and interfering with fetal oxygen supply during labor.

Abnormal Presentation

Abnormal presentation refers to babies that have not maneuvered into the normal head-first position in advance of labor and delivery. There are various abnormal presentation positions that babies can end up it such as breech position or face-first position. All of these abnormal presentations (particularly breach) will significantly increase the chances of a birth injury occurring during vaginal childbirth.

Pitocin

Pitocin is the most widely and frequently used drug in the labor and delivery room. Pitocin is an artificial copy of a naturally occurring hormone called oxytocin. At the end of a pregnancy, the release of oxytocin by the mother's body is what stimulates the uterus to start contracting and initiate the labor and delivery process. The drug Pitocin has the same stimulating effect on the uterus when administered to pregnant mothers. Doctors use it to induce labor and also to speed up labor that has already begun. For certain women, however, Pitocin can be very problematic because their bodies over respond to the synthetic form of the hormone. This over sensitive response to Pitocin hyper stimulates the uterus creating contractions that are too strong and too frequent. Hyper stimulation of contractions can disrupt the delivery of oxygen to the baby and/or force the baby through the birth canal too fast. Both of these results will increase the possibility of a major birth injury.

Epidurals

The epidural has become the most commonly utilized form of pain management for women in labor. Epidurals are a particular method of administering pain relief medications to mothers in labor. A needle is tapped into the epidural space around the mother's spine for direct administration of anesthesia that numbs the lower body. The medications given through the epidural are entirely safe. However, studies have demonstrated that epidurals increase the statistical likelihood of a birth injury occurring. The reason for this increased risk is that the epidural works too well. The medication given through the epidural is so effective at numbing the lower body that it significantly limits the mother's ability to push the baby out. Mothers who get an epidural have less feeling and less control over the muscles that are used to push during delivery. The net result is that vaginal deliveries with an epidural invariably take a lot longer than deliveries where an epidural is not given. An extended delivery process increases and prolongs the stress on the baby creating a higher chance of oxygen deprivation or other complications. Moreover, as the delivery continues to drag doctors are more likely to employ delivery assistance tools such as forceps or vacuum pumps. The use of operative delivery instruments more than doubles the potential for a birth injury.

Gestational Diabetes

Gestational diabetes is specific form of diabetes that sometimes occurs during pregnancy in certain women. When a woman becomes pregnant her body releases increased amounts of various hormones to facilitate fetal development. One of these hormones has the side effect of making the mother's body more resistant to the effects of insulin. In certain women with a pre-disposition this insulin resistance eventually makes them diabetic. If timely diagnosed, gestational diabetes can be managed very effectively so as not to increase the risk of birth injury. When not diagnosed, however, gestational diabetes can lead to a number of complications including fetal macrosomia, preeclampsia, and premature birth. All of these conditions are strongly associated with heightened birth injury.

  • Blood clots in the mother also create a grave risk to the mother and child