New and expectant mothers

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] . 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.

New and expectant mothers are considered to be an at risk group, i.e. they are more susceptible to work related injuries and ill health than the average worker^[2]. 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^{[3] [4]}.

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 chemicals have not been studied for their potential to have damaging effects on the workers' reproductive system and the effect of other workplace hazards, such as stress, noise and shift work is subject to debate^[5][6].

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^[3]. These substances can cause liver damage and other birth defects as well as miscarriage. 

Some chemical substances have been classified in the EU as hazardous for human reproduction or for new-borns through lactation. Based on the CLP regulation (Regulation 1272/2008/EC on classification, labelling and packaging of substances and mixtures)^[7], reproductive toxicants are classified as follows:

• Category 1A: Known human reproductive toxicant
• Category 1B: Presumed human reproductive toxicant
• Category 2: Suspected human reproductive toxicant
• Effects on or via lactation: evidence of adverse effects in the offspring due to transfer in the milk and/or on the quality of the milk and/or the substance is present in potentially toxic levels in breast milk.

This is indicated by hazard statements which can be found on the label and in the Safety Data Sheet. Hazard statements for reproductive toxicity are as follows:

• - H360: May damage fertility or the unborn child
• - H361: Suspected of damaging fertility or the unborn child 
• - H362: May cause harm to breast-fed children

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^[3]. Women working in hospitals, laboratories or with children or animals may be at greatest risk. 

Specific attention is required for exposure to hazardous medicinal products that can adversely affect reproductive health, leading to foetal loss, malformations in offspring, infertility, and low birth weight^[8].

Unfortunately there is a lack of scientific data on the reproductive health effects of many substances^[3], 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 trimester of pregnancy^[9] 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.

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^[10]. Reproductive and developmental toxicity information may be provided on the label of chemicals (classification and hazard statement) and in Safety Data Sheets (SDS), however the absence of such information does not necessarily mean the agent does not present a reproductive health risk. Often, due to the limited information available, professional judgement is required. 

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^[11]. 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^[11]. However, care should be taken to keep doses as low as possible and within acceptable limits. Directive 2013/59/Euratom requires that as soon as a pregnant worker informs the employer of her pregnancy, measures must be taken to ensure that the equivalent dose to the unborn child is as low as reasonably achievable and unlikely to exceed 1 mSv during at least the remainder of the pregnancy. Workers who are breastfeeding an infant, may not be employed in work involving a significant risk of intake of radionuclides or of bodily contamination^[12].

Vibration is another physical agent arousing concern, with long-term exposure to whole body vibration being linked to premature birth or low birth weight. It is therefore important for pregnant women to avoid high levels of vibration and/or prolonged exposure^[10]. 

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. However, it remains unclear whether pregnant women are more at risk of decompression sickness. When it comes to diving, for example, overall placental blood flow usually remains intact even as overall resistance in the maternal or foetal placental circulation increases, preventing adverse effects. But, pregnant workers are advised not to dive at all during pregnancy due to the possible effects of exposure to a hyperbaric environment on the unborn child.^[13][10]

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 breastfeeding^[14]. The global climate crisis magnifies the threat of heat stress, especially for pregnant women who are particularly susceptible to negative pregnancy and newborn health outcomes. Pregnant women face increased health risks related to the climate crisis, especially when engaged in occupations with a higher likelihood of exposure to climate-related impacts, such as outdoor and agricultural jobs^[15]. 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. It can also cause pre-eclampsia, which if left untreated, can lead to serious and potentially fatal complications for mother and baby^[16]. A study based on a large, national Swedish, prospective cohort, found that occupational stress as a whole was not consistently associated with pregnancy outcomes. However, the study did find that psychosocial risk factors such as lower levels of job decision authority were associated with increased risks of hypertensive disorders of pregnancy and gestational diabetes^[17].

Stress may 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 fulfil their work obligations whilst also fulfilling their parental responsibilities. Attending regular medical appointments, preparing for birth and providing childcare is very time consuming and can come into conflict with work commitments. Flexible working arrangements can help maintain a good work-life balance, alleviate stress and reduce staff turnover^[5].

Workload

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. Long hours and a heavy workload have been linked with an increased risk of premature delivery and low birth weights^[4]. 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^[18]. 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^[18]. 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^[10]. 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.

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) sets specific provisions for workers who are new or expectant mothers^[19]. 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 breastfeeding 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^[19].

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. The directive sets the minimum period for maternity leave at 14 weeks, with 2 weeks’ compulsory leave before and/or after confinement and an adequate allowance subject to national legislation. A right to 2 weeks' paternity leave was introduced in the Work-life Balance Directive for parents and carers^[20], which entered into force on 1 August 2019^[21].

Legal requirements for workplaces (Directive 89/654/EEC^[22]) outline specific requirements regarding pregnant women and nursing mothers, highlighting the necessity of providing suitable facilities to enable them to rest lying down under appropriate conditions.

Furthermore, in 2022, reprotoxic substances were brought into the scope of Directive 2004/37/EC^[23]. This means that the same strict rules apply to the protection of workers from exposure to reprotoxic substances as for carcinogens.  

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^{[24][19] [23]}. 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. Guidelines issued by the EU Commission complement the pregnant workers Directive and provide practical advice on the assessment of the chemical, physical and biological agents and industrial processes considered hazardous for the safety or health of pregnant workers and workers who have recently given birth or are breastfeeding^[10].

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 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^[18] [10]. 

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 breastfeeding to express and store their milk^[10].

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.

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, 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.