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New and expectant mothers at work

In the context of this article, new and expectant mothers are defined as workers who are pregnant or who have given birth within the previous 6 months, or are breastfeeding. New and expectant mothers perform a vital role in society and in many work organisations. Being pregnant and giving birth causes physiological and emotional changes that may or may not interfere with a woman’s ability to perform her work duties in the usual manner. Furthermore, some work activities/processes may actually put the mother and/or her baby at risk of harm.

It is an employer’s responsibility to systematically identify hazards associated with his/her business and to ensure controls are in place to minimise the risk of harm to all those who may be affected, including new and expectant mothers and their babies [1][2][3]. This article describes some of the factors that employers should consider to protect the health and safety of employees who are new or expectant mothers. It is not intended to replace medical advice.

Occupational Safety and Health (OSH) implications for New and Expectant mothers

New and expectant mothers are considered to be an at risk group at risk group, i.e. they are more susceptible to work related injuries and ill health than the average worker[1]. Although there is no evidence to suggest that women who work during pregnancy have a significantly better or worse pregnancy outcome than those who do not work, there is evidence to suggest that some work related factors, such as long hours and heavy workloads are associated with an increased risk of premature labours and low birth weights[5].

Human reproduction and the workplace factors that may adversely affect it is a complicated area where there is still much to learn. However, a number of factors often referred to as ‘reproductive hazards’ have been linked to reproductive problems. Reproductive hazards are substances or agents that may affect the reproductive health of women or men or the ability of people to have healthy children. These hazards include a wide range of chemical, physical and biological agents, and a variety of work processes or working conditions. Problems such as infertility, miscarriage, and birth defects can result from exposure to these hazards.

Exposure to reproductive hazards in the workplace is an increasing health concern but the hazards are currently not well understood by the medical and scientific communities. Most of the more than 1000 workplace chemicals that are known to cause adverse reproductive effects in animals have not been studied in humans and the effect of other workplace hazards, such as stress, noise and shift work is subject to debate [5][6]. The European Parliament published a report in 2011, entitled ‘Occupational health and safety risks for the most vulnerable workers’[7], which concluded that additional research was needed on the effect of work on female reproductive health. Despite this current lack of understanding, there are a number of workplace hazards that have been widely linked with reproductive problems.

Hazardous substances

Hazardous substances, such as toxic chemicals can impair fertility in both men and women and can enter the mother’s body and then the body of the foetus via the placenta. The foetus, being small in size and weight and having a liver with limited capacity to detoxify, is particularly vulnerable to toxins[5][8]. These substances can cause liver damage and other birth defects as well as miscarriage.

Biological agents, such as viruses, fungi spores and bacteria, can also impair fertility and can be passed from the mother to the foetus with similarly devastating effects. Several infections during pregnancy, including rubella, chicken pox, hepatitis B and toxoplasmosis have been linked with birth defects and miscarriages[5]. Women working in hospitals, laboratories or with children or animals may be at greatest risk.

Unfortunately there is a lack of scientific data on the reproductive health effects of many substances[5], and consequently, there is considerable uncertainty about what action should be taken to manage the risks. Substances that are known to present a reproductive hazard must be controlled for all staff not just those who are known to be pregnant. The developing foetus is most vulnerable to toxic chemicals during the first eight weeks of pregnancy[5] and potentially before the woman knows she is pregnant. Furthermore, some substances, such as lead can be unintentionally taken home on a worker’s skin, clothes or hair in sufficient quantities to present a reproductive hazard to their family members and others with whom they may come into contact[5].

All chemical and biological agents to which workers may be exposed to in the course of their work, must be identified and an assessment of the risk they present must be carried out[1]. Reproductive and developmental toxicity information may be provided on Material Safety Data Sheets (MSDS), however the absence of such information does not necessarily mean the agent does not present a reproductive health risk[5]. Often, due to the limited information available, professional judgement is required.

Unfortunately due to the wide range of potentially harmful substances and the current level of understanding of how these may affect the human reproductive system, it is not possible for this article to prescribe the appropriate course of action to take in each given situation. However, this lack of understanding and the foetus’ vulnerability to toxins should be motivation for employers to take a cautious approach.

Physical hazards

Ionising radiation is one physical agent known to be a reproductive hazard, having damaging effects on the fertility of women and men, and on the developing embryo/foetus[9][10]. New and expectant mothers do not necessarily need to avoid all work with radiation or radioactive materials as the radiation protection measures needed to comply with radiation protection legislation are likely to provide sufficient protection for them and their babies [9][10]. However, care should be taken to keep doses as low as possible and within acceptable limits. If a worker’s annual dose is usually between 1mSv and 6mSv it is recommended that action is taken to ensure their babies’ dose is restricted to 1mSv per year for the duration of the pregnancy[9]. If exposures are expected to be greater than 6mSv per year, it is recommended that work activities are restricted during the pregnancy or that changes are made to work processes to reduce exposure[9].

Vibration is another physical agent arousing concern, with whole body vibration being linked to miscarriages and premature deliveries. It is therefore important for pregnant women to avoid high levels of vibration and/or prolonged exposure [11].

It is also essential that pregnant women avoid hyperbaric atmospheres as these have been linked to a range of developmental abnormalities, including low birth weights, miscarriages, and birth defects, such as abnormal skull development and malformed limbs[2]. Studies have also shown that hyperbaric exposure and decompression stress affects foetal blood flow and can cause bubbles to form within the blood[13]. This can lead to abnormal heart beats and potentially to the termination of the foetus[12].

Heat stress can also be a problem for pregnant women as they are less tolerant to heat and can faint easily. During pregnancy a woman’s blood vessels dilate and her blood pressure drops. Heat exposure also causes these responses and the combination of heat exposure and pregnancy can reduce blood pressure to dangerously low levels. Heat exposure can also lead to dehydration which may impair breast-feeding[14]. Pregnant workers should not be exposed to high temperatures for prolonged periods at work. Rest facilities and access to water should be provided in those workplaces where temperatures regularly exceed comfortable levels[14].

Psychosocial issues and stress

Pregnancy and early motherhood is very demanding and can compromise a worker’s ability to cope with her usual work activities. This can cause stress, which can be particularly problematic for new and expectant mothers. High blood pressure can decrease blood flow to the placenta and can cause preterm labour or low birth weights[15]. It can also cause pre-eclampsia, which if left untreated, can lead to serious and potentially fatal complications for mother and baby[16]. Stress is also likely to put new mothers at greater risk of developing post natal depression[17]. Stress may therefore not only directly contribute to a poor pregnancy outcome; it may also impede obstetrical health and antenatal care.

Each new and expectant mother will have her own specific limitations and needs. It is important to maintain an open dialogue to understand each worker’s specific needs and to agree appropriate measures to address psychosocial issues and minimise stress.

Work life balance

New and expectant mothers can sometimes find it difficult to fulfill their work obligations whilst also fulfilling their parental responsibilities. Attending regular medical appointments, preparing for birth and providing child care is very time consuming and can come into conflict with work commitments. Flexible working arrangements can help maintain a good work-life balance work-life balance, alleviate stress and reduce staff turnover[5].


New and expectant mothers are far more susceptible to fatigue and the psychosocial issues described earlier may impede their ability to manage their usual workload[3]. Long hours and a heavy workload have been linked with an increased risk of premature delivery and low birth weights[5]. Workloads may need to be modified to reduce the risk of fatigue and stress. This could include reducing work activities, adjusting / reducing working hours, offering flexible working hours and increasing rest periods.

Musculoskeletal disorder (MSDs)

Pregnant women undergo physiological changes during pregnancy that increases their risk of developing a MSD[19]. As the pregnancy progresses, the ergonomics of their work activities (e.g. manual handling of loads and working posture) may become compromised and potentially put them at risk of developing a MSD. Hormonal changes during pregnancy can increase muscle tension and cause ligament softening and inflammation[19]. These changes increase the risk of pregnant women developing MSDs yet further. New mothers are also at risk as hormone levels may not return to normal until a few months after pregnancy.

Workplaces and processes should be ergonomically assessed to ensure they do not present a significant risk. Where possible, lifting aids should be used to avoid the need for pregnant workers to lift heavy weights, and work stations and processes should be ergonomically designed so that workers do not need to perform repetitive movements, maintain static postures for long periods, or have to twist or stretch[20]. When assessing the workspace it is important to consider the physical changes that a pregnant worker will undergo during the course of the pregnancy and it may be necessary to make a series of modifications at various stages.

Legislation and legal obligations

Council Directive 92/85/EEC of 19 October 1992 on the introduction of measures to encourage improvements in the safety and health at work of pregnant workers and workers who have recently given birth or are breastfeeding (tenth individual Directive within the meaning of Article 16 (1) of Directive 89/391/EEC) set specific provisions for workers who are new or expectant mothers[1][22]. The directive provides a set of guidelines for the assessment of the chemical, physical and biological agents and industrial processes considered dangerous for the health and safety of new and expectant mothers. It also includes provisions for physical movements and postures, mental and physical fatigue and other types of physical and mental stress. Annex II of the Directive provides a non-exhaustive list of agents and working conditions that are considered hazardous to new and expectant mothers and states that under no circumstances pregnant and breast feeding workers can be obliged to work if they may be exposed to these agents. These agents include: physical agents, namely working in hyperbaric atmosphere, e.g. pressurised enclosures and underwater diving; biological agents such as toxoplasma and rubella virus; chemical agents, such as lead and lead derivatives; and potentially harmful working conditions, i.e. underground mining work[22].

The Directive also sets out provisions for maternity leave and job security. It states that workers must not be dismissed from work because of their pregnancy and during their maternity period, which will occur from the beginning of their pregnancy to the end of the period of leave from work[22]. In 2008, an amendment to the Directive increased maternity leave entitlement from 14 to 18 weeks[23].

OSH-specific legislation at the European Union (EU) level targeting female workers has so far focused mainly on pregnant and breastfeeding workers. The risks to fertility and sexual and reproductive functioning for both women and men have been somewhat overlooked. The goal of greater female employment underlines the need to address health and safety issues that affect women, such as early menopause and menstrual disorders more effectively[7].

Risk assessment

An employer has a legal obligation to systematically identify hazards associated with their business, to evaluate the risks that they pose, and to implement control measures to minimise the likelihood of harm[1][2][3]. This process should consider the needs of all those who may be affected by any hazards that may occur within the organisation and should be reviewed regularly, particularly if work processes or a worker’s circumstances change, e.g., they become pregnant. Although most workplace hazards are likely to be as relevant to all workers, not just new and expectant mothers, the risk of harm to new and expectant mothers may be far greater and the foetus/baby itself may also be at risk.

During pregnancy an expectant mother undergoes considerable physiological changes and the foetus goes through various stages of development. Each stage of the pregnancy and early motherhood should be considered to protect the health and safety of mother and foetus/baby. Each pregnancy is different and so the specific circumstances of each individual needs to be taken into account and where appropriate, a medical professional should be consulted. It is important that the employer and employee discuss any potential issues and agree on the actions to be taken.

Working conditions and facilities

Working conditions that are unsafe for new and expectant mothers are likely to be unsafe for others and so action should be taken to protect all workers. However, the fact that new and expectant mothers may be at greater risk of injury should be recognised when risk assessing work activities, equipment and facilities, as additional measures may be required to address these risks. It is particularly important to ensure that desks and work stations allow pregnant workers to maintain a neutral posture and do not necessitate stretching and twisting[19][20].

Reasonable allowances (e.g. flexible working hours and a reduced workload) should be made to help address issues such as fatigue, morning sickness, postnatal depression and physical limitations. Time off should be provided to allow workers to attend medical appointments and, breaks and facilities should also be made available for those who are breast feeding to express and store their milk[5].

The physical and physiological changes that a women goes through during pregnancy may influence the suitability of personal protective equipment (PPE) as well as other workplace equipment, activities and facilities. It is important that these changes are considered to ensure that PPE, etc. remains fit for purpose and does not put workers at risk.

Return to work and other general considerations

Workers who are returning to work following pregnancy should be assessed to ensure that the conditions that are required for their return to work are met and that their training and PPE requirements are addressed. It is often appropriate to phase the return to allow them to readjust to the workplace and to establish a sustainable work-life balance. Training may be required to make them aware of changes to processes or to refresh their knowledge[5].

Conclusions and good practice

A legal framework is in place to protect the OSH of new and expectant mothers and to provide them with job security and maternity leave. However, this legislation provides very little OSH guidance for employers and imposes very little in terms of specific OSH measures.

It is not possible for this or any other article to be absolutely prescriptive regarding OSH protection for new and expectant mothers. Each pregnancy is different and so the specific measures required will be unique to each given case and situation. The limited understanding of how workplace hazards may affect human reproduction makes it particularly difficult to make specific recommendations and for employers to decide what measures to take. However, what is clear is that workplace hazards that have the potential to harm new and expectant mothers, also have the potential to harm others. Furthermore, many reproductive hazards pose the greatest risk during the early stages of pregnancy, potentially before a worker realises they are pregnant. Employers must therefore use the hierarchy of controls i.e. eliminate, substitute, isolate to reduce the risk to a minimum for all workers, not just new and expectant mothers. In instances where exposure to known reproductive hazards cannot be completely eliminated, consultation with medical professionals and an open dialogue with workers are essential to inform a thorough risk assessment and decide on the appropriate measures in each case.

Employers should take a particularly cautious approach when dealing with toxins and biological agents that are known to be reproductive hazards, as the foetus can be very vulnerable to their effects. A worker’s immunity to biological agents should be assessed and where appropriate immunisation should be provided. In instances where immunisation is not appropriate or may itself pose a risk, or where exposure to toxins cannot be avoided, restricted duties should be implemented to protect new and expectant mothers.

Consideration should be given to whether or not it is appropriate to extend measures intended to protect new and expectant mothers to all female workers of child bearing age.


[1] HSE – Health and Safety Executive (2012). New and expectant mothers. Retrieved 05 February 2013, from:

[2] HSE – Health and Safety Executive (2013). Pregnant Workers & Risk Assessment. Retrieved 17 April 2013, from: [2]

[3] EU-OSHA – European Agency for Safety and Health at Work (2013). Directive 89/391/EEC - OSH "Framework Directive". Retrieved 18 April 2013, from: [3]

[4] European Commission, ''Guidance on risk assessment at work'', 1996, p. 35. Available at:

[5] Eng, A. & Kelly, M., ‘New and Expectant Mothers at Work – Guidelines for Health and Safety’, ''Occupational Safety and Health Service'', Department of Labour, 1998.

[6] United States Department of Labor (2011). Reproductive Hazards. Retrieved 12 February 2013, from: [4]

[7] The European Parliament, ''Occupational Safety and Health risks for the most vulnerable workers, 2011, pp. 8-109. Available at:

[8] Powrie, R. & Kurl, R., ‘Prescribing drugs to pregnant women’, ''Women’s Health in Primary Care'', Vol. 2, No 7, 1999, pp. 547-554. 

[9] HSE - Health and Safety Executive, ''Working safely with ionising radiation: Guidelines for expectant or breast feeding mothers'', 2001, pp. 2-10. Available at: [7]

[10] Drouet, F. & Michelet, M., ‘Results of the EAN request on radiation protection of aircraft crew’ ''European ALARA Network'', 2012. Available at: [8]

[11] HSE – Health and Safety Executive (2012). Vibration HAV / WBV. Retrieved 14 March 2013, from:

[12] Held, H. & Pollock, N., ‘The Risks of Diving While Pregnant - Reviewing the Research’, ''DAN-Divers Alert Network'', March / April 2007. Available at:

[13] Powell M. & Smith M., ‘Fetal and maternal bubbles detected noninvasively in sheep and goats following hyperbaric decompression’, ''Undersea Biomedical Research'', Vol. 12, No 1, 1985, pp. 59-67

[14] HSA – Health and Safety Authority (2013). Pregnant at Work Frequently Asked Questions. Retrieved 17 April 2013, from: [10]

[15] Mayo Clinic (2006). Preeclampsia. Retrieved 05 February 2013, from: [11]

[16] NHS – National Health Service (UK) (2011). High blood pressure (hypertension) and pregnancy. Retrieved 15 April 2013, from: [12]

[17] Hatloy, I., ‘Understanding postnatal depression’, Mind, 2013. Available at: [13]

[18] NHS – National Health Service (UK) (2012). Sleeplessness and feeling tired in pregnancy. Retrieved 16 April 2013, from: [14]

[19] Goldman, M. & Latch, C., ‘Women and Health’ ''Work-related musculoskeletal disorders'', Academic Press, San Diego, 2000, pp. 484-485

[20] HSE – Health and Safety Executive (2013). Musculoskeletal Disorders. Retrieved 15 April 2013, from: [15]

[21] EU-OSHA – European Agency for Safety and Health at Work (2013). Directive 92/85/EEC - pregnant workers. Retrieved 12 February 2013, from:

[22] The Council of the European Communities, ‘Council Directive 92/85/EEC, 1992’, 1992, pp. 2-11. Available at: [17]

[23] EUROPA (2013). ‘Summaries of EU Legislation’, Protection of pregnant workers and workers who have recently given birth or are breastfeeding. Retrieved 15 April 2013, from: [18]

Further reading

EU-OSHA – European Agency for Safety and Health at Work, ‘Gender issues in safety and health at work’, Facts 42, 2003. Available at:

EU-OSHA – European Agency for Safety and Health at Work, ‘Including gender issues in risk assessment’, Facts 43, 2003. Available at:


Mark Liddle

Health & Safety Laboratory, UK