Car seatbelts in pregnancy: the practice and knowledge of pregnant women remain causes for concern

Authors

  • Helen C. Johnson,

    Specialist Registrar
    1. Department of Obstetrics and Gynaecology, York District Hospital
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  • David W. Pring

    Consultant, Corresponding author
    1. Department of Obstetrics and Gynaecology, York District Hospital
      Correspondence: Dr D. W. Pring, Department of Obstetrics and Gynaecology, York District Hospital, Wigginton Road, York YO3 7HE, UK.
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Correspondence: Dr D. W. Pring, Department of Obstetrics and Gynaecology, York District Hospital, Wigginton Road, York YO3 7HE, UK.

Abstract

Objective To evaluate current knowledge and practice among pregnant women about the use of car restraint systems during pregnancy.

Design A structured questionnaire.

Setting District hospital antenatal clinic.

Participants Two hundred pregnant women attending for their routine mid-pregnancy anomaly scan.

Main outcome measures The women were asked about seatbelt and airbag usage, source of information about restraint systems and the legal requirements and recommendations regarding car safety systems.

Results One hundred fifty-nine women (80%) completed the questionnaire. Ninety-eight percent wore seatbelts in the front, 68% wore seatbelts in the back of a car, 48% correctly identified where to place the seatbelt and 37% had received information on seatbelt use while pregnant. The latter were more likely to correctly position their restraints than those who had received no information (P= 0.03). Thirty-nine percent had an airbag system fitted and one woman had de-activated it. Fifty-eight percent were aware seatbelt use was a legal requirement for driver and passengers when fitted.

Conclusions Many pregnant women are ignorant of the correct usage of seatbelts, their positioning and legal requirements. This puts their own wellbeing, and that of the fetus, at risk. Women should receive written instructions and advice from well informed health professionals and be encouraged always to wear a correctly positioned seatbelt. Education increases compliance and correct usage.

INTRODUCTION

Lavenne developed the seatbelt in France in 1903 for use in aeroplanes and it was adopted for use in motor racing. From this approach evolved the standard three-point restraint fitted in automobiles today1. Accident investigation in a research work published by De Haven entitled ‘Injuries and death by car collision’ in the 1950s identified that in 25% of serious accidents, death was caused by ejection from the car1. Adoption of the three-point seatbelt has decreased deaths from road traffic accidents by 45% and moderate to critical injuries by 50%2. It became a statutory requirement to use seatbelts in the UK in 1983 in the front seats, and rear seats in 1991. The Department of Transport estimated that 200 lives and 7000 serious injuries a year are avoided by the compulsory use of seatbelts in front seats and that 100 deaths a year and 1000 major injuries are prevented when rear seatbelts are used in conjunction with front seat belts3.

Trauma from motor accidents occurs in 2%–3% of pregnancies, 90% of which are of a minor nature. Fetal loss is reported as occurring in 1%–3%4–6 and pregnancy outcome appears related to seatbelt use in a car accident7–12. In 1971, Crosby et al. reported that the major cause of fetal death in an accident was maternal death and this was significantly reduced by wearing a seatbelt. Fetal survival was improved if a three-point seatbelt rather than a lapbelt alone was worn1,13,14. The American College of Obstetricians and Gynecologists issued guidelines on seatbelt usage for pregnant women in 199115. Subsequent audit in the USA and Australia suggests many pregnant women are not complying with these recommendations16–21. The 1998 report22 on confidential enquiries into maternal deaths in the United Kingdom 1994–1996 has made recommendations for the UK for education and training of pregnant women and health care workers including:

  • 1The shoulder belt should go over the shoulder, collar bone and down across the chest, between the breasts.
  • 2The lap belt should be worn as low as possible under the abdomen and the unborn child.
  • 3Always wear a full seatbelt.

The purpose of this study was to determine the pattern of use and knowledge in the UK among pregnant women regarding seatbelts, airbags and current legislation. We asked for the sources of their information.

METHOD

The questionnaire was given to 200 women presenting consecutively for their routine mid-pregnancy anomaly ultrasound scan at York District Hospital. For most women this was their first hospital appointment, as the majority book in the community with midwives and general practitioners. At the booking visit it is routine to give general pregnancy advice, and primigravidae are given the Health Education Authority pregnancy book. The survey size was chosen, in the absence of reliable data, pragmatically to give both a manageable number for collection and analysis within a finite time.

Each woman was asked to complete a 51-question survey regarding use and knowledge of seatbelts and airbags while pregnant, whether they had received any information on this topic in pregnancy and their sources of information. On leaving the antenatal clinic all the pregnant women were given an information leaflet detailing the current legal position and guidance for the correct use and positioning of seatbelts23. We advised them not to deactivate airbags if fitted. The survey, submitted to and approved by the local ethics committee, was performed August—October 1998 before the release of the report on confidential enquiries into maternal deaths in the United Kingdom 1994–1996

RESULTS

Eighty percent (159/200) of the pregnant women with a mean gestation of 19 weeks and mean age of 29.4 years completed the questionnaire. Of these, 75/159 (47%) were multiparous. There were no differences in replies between primigravidae and multiparae. Eighty-one percent (125/159) were qualified drivers, 121/159 (76%) were currently employed, and 47/159 (30%) needed to drive in their employment. Seventy-nine percent (125/159) could drive, of whom 96% (152/159) thought that seatbelts saved lives in car accident. Eighty-seven percent (138/159) thought that wearing seatbelts was beneficial to them if they were involved in an accident when pregnant, while 98/159 (62%) thought that seatbelts were beneficial to the fetus in the same circumstances. Eighty-seven percent (138/159) knew that three-point seatbelts were safer for them than a lapbelt and 118/159 (74%) knew that a three-point seatbelt was safer than a lapbelt for the fetus. Three percent (5/159) had been involved in a road traffic accident while pregnant.

Fifty-eight percent (93/159) correctly responded that seatbelt use was a legal requirement. Drivers (82/125) were significantly more aware than non drivers (11/34) that wearing a belt was a legal requirement. Ninety-eight percent (156/159) always wore a seatbelt in the front seats and 69% (109/159) always wore a seatbelt in the back seat. The most common reasons for not wearing a seatbelt in the back seat were discomfort, 22% (11/50), and concerns about harming the fetus, 30% (15/50). Three subjects did not have seatbelts fitted in the rear passenger seats. One person had a medical exemption certificate.

Forty-eight percent (77/159) identified the correct position for both components of the three-point seatbelt while 37% (50/159) could recall being advised on the correct positioning of seatbelts. This latter group had a 66% (33/50) correct response rate, significantly different (χ2 test P= 0.003) when compared with women who could not remember receiving any information, 40% (44/109). Drivers (68/125) were more likely to wear seatbelts than non drivers (8/34) (χ2 test P= 0.001). The most common information sources were the Health Education Authority pregnancy book and health leaflets (17% and 8%, respectively) followed by midwives (6%), friends (4%) and magazines (4%). Doctors, police, newspapers and broadcasting were identified as sources by less than 1% of women. Six women (4%) purposely put their lapbelt component across the pregnant abdomen.

Thirty-nine percent (62/159) of women had airbag systems fitted to the steering wheel, and 20/159 (13%) had front passenger airbags fitted. One person had deactivated the airbag system. Seventy-one percent (113/159) thought that airbags increased the safety of a pregnant woman in an accident, and 27/159 (17%) thought that they were potentially dangerous to a pregnant woman.

DISCUSSION

Motor vehicle accidents are a significant contributor to deaths in pregnancy. Thirteen of 36 fortuitous deaths occurred as a result of road traffic accidents in the most recent triennial confidential enquiry report into deaths in pregnancy22. Fortuitous deaths are deaths from non-obstetric causes which happen in pregnancy or puerperium but are not considered related to the pregnancy.

Studies have unequivocally demonstrated that seatbelts and other restraint systems reduce mortality and critical injury following road traffic accidents for driver and passengers1,7–9,10,13,14,24. This is reflected in current legislation, which makes their use compulsory, with limited exceptions including taxi drivers with fare paying passenger, drivers of local delivery vehicles and holders of medical exemption certificates.

Airbags, when fitted, benefit both driver and front seat passenger in frontal crashes. The reduction of mortality is in the order of 18% with airbag as sole safety restraint2. When used in conjunction with the three-point seat-belt, the likelihood of adult fatalities is reduced by 58% compared with a 53% reduction with seatbelt alone in otherwise fatal crashes of unbelted drivers20 The common injuries secondary to airbag deployment are usually minor and include erythema and abrasions2,25,26. While the three-point seatbelt system is recognised as beneficial to the pregnant woman and her fetus by preventing maternal death1,13,14, the benefits of airbags in pregnancy are less clearly established. There is a possibility of increased fetal risk with the explosive discharge of airbag activation due to the increased girth of pregnant women. Current recommendations, however, are not to de-activate the airbag due to the perceived increased maternal protection they afford15,20. Thirty-nine percent of women surveyed had airbags fitted in their cars. This figure will rise as most new cars come with airbags fitted as standard, at least for the driver. The majority of our sample population thought airbags were beneficial.

Our study shows a difference in maternal compliance with current legislation dependent upon whether positioned in the front or rear of their car. Ninety-eight percent of women chose at all times to wear front seat restraints. However, only two in three women always choose to use seatbelts in the back seats. This is illegal and less safe for the mother and dangerous for the front seat occupants3,27. The most common reasons given for not wearing a seat belt in the rear seats, discomfort and fear of harming the fetus, were similar to previous research5,19. A survey28 of a largely Hispanic population, selected in part on their level of educational attainment, in California revealed poor knowledge of seatbelt use in pregnancy. Although there was a high compliance with legislation, many were worn incorrectly. Few members of this population had received information from health care providers. Benefit in terms of correct positioning was found from providing information early in pregnancy, though this was not recalled by over 70% of women when re-surveyed after three months. However, both this survey and our own rely on the women's answers to the questionnaire, unsubstantiated by independent observation of their seatbelt wearing practice. This may lead to bias. Other surveys from the United States, where 44.6% of respondents always wore front seatbelts5, have used objective photographic evidence to assess front seatbelt compliance.

Only 58% of our respondents were conversant with current legislation regarding seatbelt use, although 81% were qualified drivers. This information is well publicised and documented in the regulations of the Highway Code on which all qualified drivers have been tested.

The recommendation for the United Kingdom in the current maternal mortality report for wearing a three-point seatbelt is: the shoulder belt should go over the shoulder, collar bone and down across the chest, between the breasts. Wear the lap belt as low as possible under the abdomen and the unborn child. Always wear a full seatbelt22. This accords with other published recommendations3,15,20,28–31. This positioning was initially adopted following case reports of injuries sustained when the lapbelt component was placed across the gravid abdomen9,32,33. Pearlman and Viano20, using a inanimate model known as a ‘pregnant crash test dummy’, have confirmed this strap position as the optimum to reduce the likelihood of injury to both maternal and fetal compartments.

Over half of the respondents could not identify the correct position for both components of a three-point seatbelt. Other studies have shown that up to 22% of women were purposefully wearing the lap belt portion over the pregnant abdomen5,19,30. There was a significant difference in correct placement of the seatbelt between those that recalled receiving advice or information and those who had received no instruction. Education has been shown to increase correct belt positioning5,18,19 where up to 77% correctly wore the seatbelt after instruction. Pearlman and Phillips5 suggest that a 1–2 minute discussion accompanied by a simple written instruction is sufficient. Maternity units in the UK have been reported as giving variable quality and quantity of information to pregnant women on seatbelt use. Some advice was considered dangerous by the authors29. General practitioners surveyed in Ireland felt that they were able to give advice but rarely volunteered information34. Surveys of midwifes and general practitioners in West and North Yorkshire in late 1998 suggests incomplete knowledge involving car restraint systems (H. C. Johnson and D. W. Pring, unpublished data). Pregnancy magazines and pregnancy information books35 for the expectant mother focus predominantly on postnatal child restraint systems and little is written to highlight correct use of car restraints in pregnancy, possibly reflecting commercial interests of advertisers in the many publications.

York has neither major social deprivation nor a large ethnic minority community. Seventy-six percent of the respondents to the survey were employed. Responses may be different in areas with a different demographic distribution and this merits further investigation.

There is a need for further information and research about pregnancy and airbag safety systems. A prospective audit of outcomes of pregnant women attending Accident and Emergency departments after motor vehicle accidents should be considered, especially in cases where there has been airbag deployment. There should be follow up of the babies to determine the immediate outcomes and long term sequelae in nonfatal accidents as there is evidence to suggest an increased risk of fetal growth retardation12 and possible neurological handicap36. Inanimate studies with a modified pregnant crash test dummy, incorporating a placental unit20 may determine ways of limiting placental bed injury, a cause of intrauterine death.

CONCLUSION

A correctly fitted seatbelt should be worn in pregnancy to reduce risk of maternal and fetal morbidity and mortality. We have shown a failure of women to wear seat-belts in the rear seats as well as ignorance regarding approved seatbelt positioning and current legislation. Education appears to be an effective and simple way to achieve compliance with guidelines for belt use. Advice should be given as early as possible in pregnancy and repeated at intervals to emphasise its importance. A nationwide awareness programme for both health care professionals and pregnant women should be considered to encourage the correct positioning and universal seat belt usage. Publications targeting pregnant women should stress the importance of in-car safety for the pregnant woman and her fetus, as well as for the newborn and infant passenger.

Acknowledgements

The authors would like to thank all the staff at York District hospital antenatal clinics for their help and enthusiasm.

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