CASE SCENARIO

32 yo female pregnant patient who is 18 weeks pregnant presents to the emergency department for OBGYN consult after a motor vehicle accident incident. Patient breaked abruptly due to the incoming of a speeding car and made impact with the steering wheel and experienced tension with the seat belt. Patient experienced sharp abdominal pain rated a 7/10 that radiates to the lower back.

SEARCH QUESTION :

Should pregnant patients be advised to avoid driving to reduce the likelihood of pregnancy complications due to motor vehicle accidents?

QUESTION TYPE : 

Prevalence Screening Diagnosis

Prognosis Treatment Harms

Assuming that the highest level of evidence to answer your question will be meta-analysis or systematic review, what other types of study might you include if these are not available (or if there is a much more current study of another type)? Please explain your choices. 

If meta-analysis or systematic review are not available, I would look for retrospective cohort studies. Although the next best study would be a randomized control trial, this study would not be feasible to expose pregnant mothers to motor vehicle accidents. Retrospective cohort studies would be able to shed light on incidents that have already occurred and to evaluate for any patterns to the findings. Furthermore, retrospective cohort studies may be able to encompass a larger number of participants over a wide geographic area to provide diverse data. Retrospective studies may also provide insight on long-term consequences of motor vehicle accidents that may not be immediately observable right after an accident. For example, accidents may carry consequences into childhood development or maternal complications to conceive in the future. 

PICO SEARCH TERMS :

P	I	C	O
Pregnant Mothers	No driving	Driving	No pregnancy complications
Expectant Mothers	Abstain from driving	Motor vehicle use	Fetal safety
Pregnant Patient	Avoid motor vehicle use	Behind the wheel	No fetal complications

SEARCH TOOLS & STRATEGIES USED :

Please indicate what databases/tools you used, provide a list of the terms you searched together in each tool, and how many articles were returned using those terms and filters. 

Database	Filter	Terms Searched	Articles Returned
PubMed	Meta- AnalysisSystematic ReviewCohort Studies2010 – 2021	Pregnant women driving	64
Pregnant women motor accident	5
JAMA	Research Review2010-2021	Pregnant women motor accident	14
Cochrane	Review2010- 2021	Pregnant driving	2

My first priority was to ensure that high-level journal articles were searched for. This would ensure that the quality of content was sufficient to make a definitive clinical bottom line. For this reason, my first step was to include meta-analysis and systematic review. However, as stated above, I did not include a randomized control trial as subjecting mothers to motor vehicle accidents would be unethical. Instead, I chose to include cohort studies as this could include evaluations from past incidences to draw a conclusion as to whether motor vehicle accidents had an impact on pregnancy. For all of the above mentioned filters, I also included the most recent ten years for the most relevant data as changes in automobile design, driving laws, and hospital protocol can influence outcomes. 

RESULTS FOUND :

Article 1

Citation: Miller N, Biron-Shental T, Peleg K, Fishman A, Olsha O, Givon A, Kessel B. Are pregnant women safer in motor vehicle accidents? J Perinat Med. 2016 Apr;44(3):329-32. doi: 10.1515/jpm-2015-0163. PMID: 26356252.

Type of Study: Retrospective Cohort Study

Abstract: As motor vehicle accidents are a major cause of pregnancy-related maternal deaths in the U.S., this study was performed to see if there was any association between MVA’s and poor outcomes for the fetus in mother. This study also evaluated whether seat location had an impact on fetal and maternal injury and risks.

Methods :This study was performed by looking at data collected from the Israeli National Trauma Registry from 2006 – 2013 of 2794 pregnant  female patients and 3,441 non-pregnant patients aged 18 – 40 years old who were involved in a MVA. 67% of the participants were drivers and 33% were non-drivers.

Results :Pregnant patients had a lower injury severity core than non-pregnant patients (p < 0.001). 38% of the pregnant patients had adverse-maternal-fetal outcomes. To further break this down, 0.1% experienced placental abruptions and 0.2% experienced micarriage. 0.03% of patients experienced mortality as compared to 0.93% mortality rate in  non-pregnant patients. There was a negative correlation found between gestational age and spontaneous abortion (p < 0.009).

Reason for Selection: This article was selected as it contained a large database of pregnant patients who were involved in a motor vehicle accident within the last 15 years. This provided a broad overview to identify any patterns between motor vehicle accidents and pregnant patients. Furthermore, MVAs involving non-pregnant patients were also included. This constructs a type of control to see how MVAs specifically impact pregnant patients. The study also provided a unqiue perspective as to whether passenger seating influenced risks in pregnant patients.

Conclusion :This study found that the rate of MVA injury and mortality was lower in pregnant patients compared to non-pregnant patients. Furthermore, pregnant patients had a lower severity of trauma than non-pregnant patients.

Key Points:MVAs inrease the risk of placental abruptions, miscarriage, and mortality in pregnant patientsThe lower the gestational age, the greater the risk of spontaneous abortionPregnant patients present with a lower risk of injury and mortality compared to non-pregnant patientsPregnant drivers presented with lower severity of MVA trauma than non-pregnant patients

Article 2

Citation: Amezcua-Prieto C, Ross J, Rogozińska E, Mighiu P, Martínez-Ruiz V, Brohi K, Bueno-Cavanillas A, Khan KS, Thangaratinam S. Maternal trauma due to motor vehicle crashes and pregnancy outcomes: a systematic review and meta-analysis. BMJ Open. 2020 Oct 5;10(10):e035562. doi: 10.1136/bmjopen-2019-035562. PMID: 33020077; PMCID: PMC7537450.

Type of Study: Meta Analysis

Abstract: This study reviewed the effects of motor vehicle crashes on pregnant patients and fetal outcomes.

Methods :A meta-analysis was conducted using data from Medline, Embase, Web of Science, Scopus, Latin-American and Caribbean System on Health Sciences Information, Scientific ELectronic Library Online, TRANSPORT, International Road Research Documentation, European Conference of Ministers of Transportation Databases, Cochrane Database of Systematic Reviews, and Cochrane Central Register. Follow-up with participants was conducted in secondary care, collision and emergency, and inpatient care. Data was then evaluated by estimated per 1,000 women. Quality of studies was then assessed with the Newcastle-Ottawa Scale. No language or date restrictions were applied to electronic searches. Terms searched were “motor vehicle collision”, “road traffic collision”, “crash”, “collision” and “pregnant women”, “gravid women”, “childbearing women”, or “maternal”.

Results : 19 studies that included 3, 222, 066 women showed that maternal death occurred in 3.5/1000 (95%, Cl 0.25-10.42) and fetal death or stillbirth occurred in 6.6/1000 (95%, Cl 0.25, 10.42). 276.43/1000 of patients had induction of labor (95% Cl 262.54-290.54), 191.90/1000 needed preterm delivery (95%, Cl 47.34 – 339.00), 42.44/1000 for PROM, 17.09/1000 required hospital admission, 16.14/1000 had placental abruption, and 15.19/1000 experienced neonatal respiratory distress.

Reason for Selection: This article was selected as it was a meta-analysis of female pregnant patients involved in a motor vehicle accident. This ensured that data was pooled from a variety of sources and put through a rigorous selection process. Furthermore, the study was performed in 2020 and included the most relevant information.

Conclusion : The findings concluded that motor vehicle accidents increased the risk of maternal death and complications in both pregnant women and fetuses. The greatest flaw in the study, however, was that none of the 19 studies had a prospective design. This meant that data was chosen by random method of sampling and increased the risk of bias. Furthermore, the outcomes were not reported by trimester, did not assess for seatbelt-use, and the majority of the studies were conducted in the United States.

Key Points:MVAs increased the risk of maternal and fetal birthMVAs increased induction of labor, preterm delivery, and premature rupture of membranesMVAs increased hospital admission, placental abruption, and neonatal respiratory distress

Article 3

Citation: Chang YH, Cheng YY, Hou WH, Chien YW, Chang CH, Chen PL, Lu TH, Yovita Hendrati L, Li CY, Foo NP. Risk of Mortality in Association with Pregnancy in Women Following Motor Vehicle Crashes: A Systematic Review and Meta-Analysis. Int J Environ Res Public Health. 2022 Jan 14;19(2):911. doi: 10.3390/ijerph19020911. PMID: 35055738; PMCID: PMC8775890.

Type of Study: Meta-Analysis

Abstract: This study was performed to examine the association between motor vehicle crashes and mortality risk between pregnant women versus non-pregnant women. Pregnant women are at a greater risk of experiencing soft-tissue edema, difficult surgery interventions, and poor adverse outcomes if exposed to trauma. As motor vehicle crashes account for the largest number of reported trauma during pregnancies, this study aimed to find a correlation between the two.

Methods :Data was collected through PubMed, Embase, and MEDLINE databases. The Newcastle-Ottawa Scale (NOS) was used for quality assessment. There were two inclusion criteria for the study : (1) Studies examined the mortality rate associated with motor vehicle crashes. (2) Studies were conducted in both pregnant and non-pregnant women. Additionally there were two exclusion criteria : (1) case reports, qualitative reports, comments, simulation studies, reviews (2) studies that did not report information relevant for key clinical questions (ex. Reports that did not provide adequate information about death following motor vehicle crash).

Results :251 of 297 articles were reviewed. In the end, only 8 observational studies that evaluated retrospective cohort studies proved eligible. The studies investigated 14,120 pregnant women and 207, 935 non-pregnant women who were involved in a motor vehicle accident. It was found that pregnant patients experienced a moderate but insignificant association with in-hospital mortality than non-pregnant patients (95%, Cl = 0.38-1.22) Pregnant women were also found to experience less severe injuries in age-matched analyses. However, if the severity of trauma increased, the likelihood of mortality increased in pregnant patients compared to non-pregnant patients.

Reason for Selection: This article was selected as it was a meta-analysis that pertained to the demographic and incident presented in the PICO question. It also contained specific parameters for studies that were included, Furthermore, the study compared pregnant patients and non-pregnant patients in terms of severity of trauma. This ensured that there was some type of control to evaluate the outcomes of pregnant patients in motor vehicle collisions as creating such a design would be unethical.

Conclusion : The study demonstrated how pregnant women injured in a motor vehicle crash experienced moderate but insignificant association with lower risk in-hospital mortality than non-pregnant women (OR = 0.68, 95% Cl = 0.38 – 1.22). However, if the injury increased in severity, pregnant women experienced a higher risk of mortality than non-pregnant women. This is likely due to the shunting of blood away from uteroplacental circulation to the site of trauma that may result in fetal decline. Altered anatomical states during pregnancy could present an additional layer of challenge for trauma surgeons and complicate rescue treatments. However, the study acknowledges that the studies may present with surveillance bias as they were based on reports from clinical institutions.

Key Points:Moderate to low risk of mortality in pregnant patients compared to non-pregnant patientsHowever, there is a direct relationship between the severity of injury and risk of mortality in pregnant womenPhysiological and anatomical changes present with complications for surgeons, fluid care, and blood loss in pregnant patients who experience traumaLimitations in study include surveillance bias as data was collected based on clinical reportings rather than a structured research design

Weight of Evidence:

When weighing evidence, I believed Article 3 was the strongest. Article 3 was a meta-analysis with a large number of participants. Furthermore, it was conducted on a global scale through multiple reputable databases to allow for a diverse collection of information. Article 2 was the next strongest study. Although it presented with the largest number of participants, the study was conducted in the United States alone. This presents with the issue of a lack of diverse settings that could skew results. For example, the United States demonstrates different driving regulations and hospital protocol that could influence the data outcomes. Lastly, I would argue that Article 1 presents with the weakest evidence. As it is a retrospective cohort study, it does not provide the same breadth of material as the meta-analyses. Furthermore, data was limited to the United States and presents with similar drawbacks as discussed about Article 2. 

What is the clinical “bottom line” derived from these articles in answer to your question?

The clinical bottom line is that there is no strong evidence to advise pregnant women to stop driving. Although motor vehicle accidents present with undeniable risks in loss of fetus, maternal mortality, preterm delivery, and other labor complications, they were found to generate only a low to moderate risk of negative outcomes compared to non-pregnant patients. Instead, patient education may be implemented instead. For example, pregnant patients may be advised to drive in a safer vehicle, at slower speed limits, right lane of highways, avoid abrupt braking, and be more vigilant of surrounding drivers. On the other end, hospitals can work to develop and improve a universal and rapid response to pregnant patients involved in a motor vehicle accident. This would include fluid resuscitation, blood transfusion, readily available imaging tools, and a prepared surgical team. Unfortunately, accidents do occur due to chance encounters. Pregnant mothers should not be discouraged from driving, but instead take necessary precautions and understand the risks involved.