Pregnancy and lifting. Final report on HSE contract SC/89 42/247/1

The Manual Handling Operations Regulations, 1992 state that employers should make suitable allowances for pregnant employees as they could be considered to be more susceptible to manual handling injury. A preliminary draft of a CEN standard on this topic has recommended mat pregnant women and those who have recently given birth should not lift more than 10kg occasionally and 5kg frequently. However, a review of the literature on mis topic showed that, whilst a few studies showed a relationship between heavy lifting and pregnancy outcome, the guidance on what constituted heavy lifting was decidedly sparse.Because of the ethical problems which might be associated with asking pregnant women to lift weights it was decided to adopt a different approach. The objectives of this study therefore were to examine the naturally occurring handling habits of women during the last trimester of pregnancy and to examine whether any relationship could be established between handling activity during mis period and the subsequent outcome of the pregnancy.Pregnant women were recruited to the study during visits to a hospital ante-natal clinic. They were asked to record the heaviest weight lifted in a day and the heaviest frequently lifted weight (where “”frequently”” was defined as five or more times in a day). Of the 324 women approached, 316 were recruited into the study. Care was taken to try to avoid consciously choosing to approach those who “”looked cooperative”” and mis level of agreement was encouraging. Recruitment was at three levels: 123 “”diary fillers””, who agreed to complete a daily diary of lifting activities for a detailed period; 178 “”returns”” who agreed to participate by completing short questionnaires on return visits; and IS who agreed only to access to their medical notes after completing an initial questionnaire. In addition to handling activities, details were collected on other habits known to influence pregnancy outcome (eg. smoking). During the study period records were made of the occurrence of “”minor complications”” (low back pain, varicose veins, etc). After delivery details were obtained from hospital records of pregnancy outcome, birthweight, and any other major complications.The incidence of all major complications amongst the study group was lower than that for all births at the hospital and for the whole of Scotland. For example, only one child was stillborn compared to an expected two. Because of this, the only major pregnancy outcome which could be analysed with any degree of reliability was the birthweight of the child (or children).Heaviest weights lifted during the study period ranged from 0.5 to over 25kg with a median of 15kg. Heaviest frequently lifted loads showed a slightly lower maximum weight giving a bimodal distribution with peaks at 2-3kg and 12-14kg. It is interesting to note, in the context of the numerical guidelines accompanying the Manual Handling Operations Regulations 1992, that a considerable number of participants in this study lifted weights, some of them on a regular basis, which might be considered to present a degree of risk to healthy non-pregnant females. Descriptors of weights handled on either a “”one-off or frequent basis showed no relationship with birthweight although birthweights did show the expected sensitivity to smoking status. Analyses to indicate whether this lack of a relationship could be attributed to changes in handling habits as the pregnancy progressed showed reported weights to be remarkably consistent with time, either because the objects handled were already comparatively trivial, such as a kettle of water, or because they were virtually unavoidable, such as another child.Although the incidence of minor problems was in some cases quite high (75% reported low back pain at some time during pregnancy) none of these variables showed any relationship with weight handled.A number of interesting comments can be made regarding the data collected. Firstly, the weights handled by women in the later stages of pregnancy were, as a matter of course, often well in excess of the provisional limits previously indicated. It could be suggested from this that the existing limits are conservative, although whether unduly so is open to question.At a simplistic level it could be suggested that any effect on birthweight of lifting during pregnancy is less than that attributable to smoking, although this does not take into account the complexities of the variables. Certainly there does not appear to be a strong effect of lifting.In conclusion, pregnant women reported lifting weights during the latter stages of pregnancy which would create a degree of injury risk to the non-pregnant female. Although over 300 women were recruited to the study this number proved to be insufficient to examine the effect of lifting on pregnancy given the low incidence of adverse outcomes. There appeared to be some form of healthy volunteer effect in the selection of recruits despite efforts to avoid this. This could simply be because those most at risk are those who do not keep ante-natal clinic appointments.Amongst the recruits no effect of reported handling activity could be detected on pregnancy outcome (birthweight), although the sample was sufficient to demonstrate the anticipated effect due to smoking. However, while generalisations of these findings should only be made with extreme caution, they do indicate that the suggested manual handling limits for pregnant women are conservative. “”