Vacuum Assisted Delivery and Birth Injuries
In some cases during a difficult vaginal childbirth, the baby may require more than just normal pushing to pass through the birth canal. When this difficulty is encountered OB/GYNs have various delivery assistance tools at their disposal. One of the most widely used obstetrical tools is what is known as a vacuum extractor or vacuum pump. The vacuum is an assistive device that is meant to augment maternal expulsive efforts by gently guiding the fetal vertex through the birth canal.
How does it work? A vacuum extractor has a soft suction cup attached to a leverage handle. The suction cup is designed to grip onto the baby's head and it is connected to a vacuum pump to create a suction seal on the head. The doctor basically places the suction cup over the accessible portion of the baby's head, turns on the pump to create a sealed grip, and then uses the handle attached to the cup to pull and maneuver the baby out.
Whenever the doctor uses tools, such as a vacuum extractor or obstetrical forceps, the procedure is referred to as an "operative vaginal delivery." Current research suggests that approximately 1 out of every 20 (or 5%) live births in the U.S. are the result operative vaginal deliveries. However, in certain regions of the country operative delivery rates are as high as 20-25%. Vacuum extractors have extensively replaced obstetrical forceps as the tool of choice for operative vaginal deliveries. Over 80% of all operative deliveries are done with some type of vacuum extractor pump rather than forceps. Part of the reason for this trend has been the high rate of injuries associated with the use of forceps. Outside the obstetrical community, forceps have become notorious for causing head injuries to babies. Even though vacuum devices are generally considered safer than forceps, vacuum pump extractors actually causes thousands of birth injuries every year.When is Vacuum-Assisted Delivery Appropriate?
Because vacuum extractors increase the risk of injury, doctors are only supposed to use them under certain circumstances. The American College of Obstetricians and Gynecologists (ACOG) published guidelines in 2000 setting forth a list of circumstances in which vacuum extractor may be appropriate. The ACOG guidelines list the following circumstances as indications for vacuum-assisted delivery:
|Prolonged 2nd Labor Stage||Prolonged labor in the 2nd phase is generally defined as no progress after 3 hours (with epidural anesthesia) or 2 hours (without epidural)|
|Fetal Stress||Indicators of potential fetal stress (e.g., abnormal fetal heart rate) may call for vacuum assisted delivery - but only if delivery with vacuum assistance can be accomplished faster than C-section.|
|Shortening of 2nd Labor Stage||For mothers with health conditions that make pushing difficult or problematic (e.g., maternal cardiovascular disease), vacuums can be used to electively shorten the 2nd labor stage and help them along.|
|Maternal Exhaustion||Vacuum extraction may be appropriate when the mother has become physically exhausted from pushing. This is a highly subjective indication with no universal definition.|
It is important to note that all of these indicators are far from absolute because in each of these situations an emergency C-section might also be an appropriate and possibly better response than vacuum extraction.How Vacuum Extractions Go Wrong
If everything goes right and the doctor employs the required level of skill and technique, vacuum extraction is a perfectly safe way to facilitate a difficult vaginal delivery. Unfortunately, the labor and delivery room is not a place where things always go according to plan and even the best OB/GYNs occasionally make errors in judgment and/or skill. No matter what the surrounding circumstances may be, using a vacuum device immediately increases the overall risk of a birth injury. Birth injuries related to vacuum-assisted deliveries usually happen in one of several ways: (1) the doctor incorrectly places the cup of the vacuum pump in the wrong position on the baby's head; (2) the doctor chooses the wrong vacuum cup size or type for the baby's head; (3) the doctor twists the neck and head too much; (4) the doctor pulls with excessive force or in the wrong direction; or (5) the doctor spends too long using the vacuum before opting for an emergency C-section. The doctor cannot over commit to vacuum-assisted vaginal delivery and must be willing to abandon the effort in favor of a C-section when necessary.Common Birth Injuries Resulting From Vacuum Extraction
When vacuum-assisted deliveries go wrong, they tend to result in certain types of birth injuries which can range from minor to very severe. External head trauma from vacuum extraction errors can often lead to serious infant brain damage.
- Subgaleal Hematoma: a subgaleal hematoma is a rare and potentially life-threatening type of head injury that can result from a vacuum extraction error. Subgaleal hematomas occur when emissary veins surrounding the skull and brain are ruptured by external head trauma. The rupture of these veins causes blood to pool up in the area between the skull and the scalp causing swelling and internal pressure. As the blood continues to pool around the head the pressure and interruption of blood flow can injury the baby's brain. When babies are born with subgaleal hematomas it is frequently related to vacuum extraction.
- Cephalohematoma: a cephalohematoma is less serious type of pooling of blood around the head. Cephalohematomas occur in a different area of the head than subgaleal hematomas and are much less serious because the blood accumulation is more contained and less likely to spread and cause further brain injury.
- Hydrocephalus: hydrocephalus is a serious type of injury that occurs when external head trauma causes swelling which blocks the circulation of cerebrospinal fluid (CSF) out of the brain ventricles. The blockage causes CSF to accumulate within the brain causing dangerous internal swelling that often results in permanent damage to the brain.
- Levin, G, Elchalal, U, et, al: Risk factors associated with subgaleal hemorrhage in neonates exposed to vacuum extraction. Acta Obstet Gynecol Scand 2019; 98(11):1464-1472 (authors surprisingly did not find a correlation between subgaleal hemorrhage and vacuum duration or the number of dislodgements).
- Hanigan WC, Morgan AM, Stahlberg LK, Hiller JL. Tentorial hemorrhage associated with vacuum extraction. Pediatrics 1990;85(4):534-9 (reaches opposite conclusion as the Levin article in 2019 that found that the "forces generated on the fetal cranium by vacuum extraction are similar to those produced by forceps and result in tentorial laceration, venous rupture, and subdural hemorrhage).
- Lindgren L. The influence of pressure upon the fetal head during labour. Acta Obstet Gynecol Scand 1977;56(4):303-9 (discussing pressure on the fetal head).
- Mann LI, Carmichael A, Duchin S. The effect of head compression on FHR, brain metabolism and function. Obstet Gynecol 1972;39(5):721-6 (study on effect of fetal head compression on heart rate and cerebral function in sheep).
- Medlock MD, Hanigan WC. Neurologic birth trauma. Intracranial, spinal cord, and brachial plexus injury. Clin Perinatol 1997;24(4):845-57.