“Ugh, another pulled muscle?!?” Annalisa, who just entered her 34th week of pregnancy, stopped walking and sat down at a nearby bench to catch her breath. Her 4-year old daughter looked at her curiously. She had been growing inpatient, counting down the weeks until she could meet her new baby brother, and her heart flipped every time her mother touched or looked down at her growing pregnant belly. But as she watched her mother clutch her right side and wince for the 2nd day in a row, even she knew that something was off.
A few hours later, Annalisa was lying in a hospital bed, an IV catheter in place, and receiving antibiotics and fluid therapy. The on-call surgical resident, assisted with a focused ultrasound, made the diagnosis of appendicitis. Her right-sided pain, often mistaken for muscle strain or pregnancy itself, was also characteristic of her actual diagnosis. It was not the first appendix case of the day; a couple younger patients had come through the same operating room with similar diagnoses, surrounded by anxious parents, and were now comfortably resting or on their way home. Still, as the resident watched the fluttering heart beat on the baby monitoring device, it became clear that her team would be caring for two people. This was an impetus for the astute doctor to call the anesthesiologist and obstetrician and discuss special plans for Annalisa.
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In 2016, more than 6 million women in the United States gave birth, and more than 75,000 pregnant females undergo surgery every year. Thus, it is very common for our patients to ask about the indications and risk of anesthesia and surgery, should it be required, during the course of the pregnancy. All female patients of childbearing age are typically required to take a urine pregnancy test as part of the pre-operative evaluation, and a blood sample is taken to confirm any positive results from the urine test. As a general rule, healthcare practitioners counsel patients to postpone all non-urgent surgeries and procedures until a couple months after the baby is born. However, certain emergency procedures are needed to protect the well-being of the mother, which takes a priority over the fetus in the case of medical or surgical emergencies. For example, appendectomies (i.e. removal of the appendix due to infection and inflammation) are performed because the risk of severe infection (e.g. sepsis) or rupture would threaten the mother and fetus.
If surgery is needed, it is necessary for the healthcare practitioner to discuss the indications, risks, and benefits fully with the patient. Fortunately, maternal risk for non-obstetric surgery is minimal and not significantly different compared to that of the general population. However, both physicians and patients must appreciate the significant changes that happen to an expectant mother’s physiology, including dramatic increases in the work of the heart and lungs and the metabolic and nutritional needs to cover the baby on board.
Similarly to the mother, risks to a developing fetus are minimal, with the vast majority of studies showing no difference in the incidence of birth defects in comparison to the general “background” risk of 3-5% after the first trimester, when the majority of the baby’s organs develop.5 These same studies emphasize the importance of limiting exposure to the shortest possible duration and avoiding repetitive dosing. In addition, patients and their surgeons are recommended to wait until the second trimester to schedule required surgery. There is a slight increase in the risk of miscarriage and pre-term labor for surgeries taking place during the first and third trimester, respectively.
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Annalisa is understandably anxious after having discussed her diagnosis, but feels reassured after discussing these statistics and the safety measures employed by our team.
Anesthetic choice is relevant to avoid unnecessary exposure of narcotics to the mother and fetus, and a regional anesthetic (e.g. epidural, nerve block, local skin infiltration) can help achieve these means.
Fetal monitoring: Starting in the 2nd trimester, special electrodes and pads can be used to monitor the mother’s baby’s heart rate during surgery. In hospital settings, an obstetric consultant or team will be present to monitor fetal well-being and intervene if the pregnancy is deemed to be at risk.
Emergency Protocol: Although CPR and similar life support measures are extremely rare, a strict protocol is followed for all pregnant female patients with unstable vital signs. The patient is tilted slightly to the left (“left uterine displacement”) to decrease the pressure exerted by the womb on the major blood vessels returning blood from the legs to the heart. If the patient is unable to breathe independently, airway access is obtained and supplemental oxygen is administered. In critical cases, intentional pre-term delivery of the baby can be undertaken to improve the outcomes of CPR.
The operation goes smoothly, for both Annalisa and her baby, and she is discharged home the next day.
References:
- https://www.guttmacher.org/united-states/pregnancy
- Goodman S. Anesthesia for nonobstetric surgery in the pregnant patient. Semin Perinatol 2002;26:136–145.
- Cohen-Kerem R, Railton C, Oren D, Lishner M, Koren G. Pregnancy outcomes following non-obstetric surgical intervention. Am J Surg. 2005;190:467-73.
- Content and Format of Labeling for Human Prescription Drug and Biological Products; Requirements for Pregnancy and Lactation Labeling (Federal Register/Vol. 73, No. 104/Thursday, May 29, 2008)
- Hoyert DL, Mathews TJ, Menacker F, et al. Annual summary of vital statistics: 2004. Pediatrics 2006;117:168–83.