Menstrual disorders and subfertility in Spanish hairdressers

Association of hairdressing with cancer and reproductive diseases: A systematic review

OBJECTIVES

To review recent epidemiological studies investigating carcinogenic or reprotoxic effects among hairdressers who seem to be at greater risk for systemic adverse effects of chemicals released from hair care products than consumers.

METHODS

A systematic review according to the PRISMA-P guidelines was performed and included studies published from 2000 to August 2021, in which cancer or adverse reproductive effects were diagnosed in 1995 and onward. Data were synthetized qualitatively due to the small number of studies, heterogeneity of study designs, outcomes, and methods.

RESULTS

Four studies investigating cancer frequencies and six studies investigating effects on reproduction among hairdressers were identified. All were of good quality and with low risk of bias. Only one of the four studies found an increased risk of cancer reporting nine times higher odds for bladder cancer in hairdressers than the population-based controls. Three other studies investigating bladder and lung cancer, and non-Hodgins lymphoma did not find an increased risk in hairdressers. Regarding reprotoxic effects, numerous outcomes were investigated including menstrual disorders, congenital malformations, fetal loss, small-for-gestational age newborns, preterm delivery, and infertility. Increased risk was found for ventricular septal defect in newborns of fathers working as hairdressers. Furthermore, several indices of poor neonatal or maternal health were significantly associated with mothers working as hairdresser.

CONCLUSIONS

Despite the scarce evidence that hairdressers are at increased risk of carcinogenic or reprotoxic effects related to their trade, such health risks cannot be ruled out. Therefore, preventive efforts to diminish occupational exposures to hairdressing chemicals should be targeted.

Exposure to non-persistent chemicals in consumer products and fecundability: a systematic review

BACKGROUND

Exposure to non-persistent chemicals in consumer products is ubiquitous and associated with endocrine-disrupting effects. These effects have been linked to infertility and adverse pregnancy outcomes in some studies and could affect couple fecundability, i.e. the capacity to conceive a pregnancy, quantified as time to pregnancy (TTP).

OBJECTIVE AND RATIONALE

Few epidemiologic studies have examined the impact of non-persistent chemicals specifically on TTP, and the results of these studies have not been synthesized. We undertook a systematic review to summarize the strength of evidence for associations of common non-persistent chemicals with couple fecundability and to identify gaps and limitations in the literature, with the aim of informing policy decisions and future research.

SEARCH METHODS

We performed an electronic search of English language literature published between 1 January 2007 and 25 August 2017 in MEDLINE, EMBASE.com, Global Health, DART/TOXLINE, POPLINE and DESTAF. We included human retrospective and prospective cohort, cross-sectional and case-control studies that examined phthalates, bisphenol A, triclosan, triclocarban, benzophenones, parabens and glycol ethers in consumer products, and considered TTP or fecundability as an outcome among women, men and couples conceiving without medical assistance. We excluded editorials, opinion pieces, introductions to special sections, articles that described only lifestyle (e.g. caffeine, stress) or clinical factors (e.g. semen parameters, IVF success). Standardized forms for screening, data extraction and study quality were developed using DistillerSR software and completed in duplicate. We used the Newcastle-Ottawa Scale to assess risk of bias and devised additional quality metrics based on specific methodological features of fecundability studies.

OUTCOMES

The search returned 3456 articles. There were 15 papers from 12 studies which met inclusion criteria, of which eight included biomarkers of chemical exposure. Studies varied widely in terms of exposure characterization, precluding a meta-analytic approach. Among the studies that measured exposure using biospecimens, results were equivocal for associations between either male or female phthalate exposure and TTP. There was preliminary support for associations of female exposure to some parabens and glycol ethers and of male exposure to benzophenone with longer TTP, but further research and replication of these results are needed. The results provided little to no indication that bisphenol A, triclocarban or triclosan exposure was associated with TTP.

WIDER IMPLICATIONS

Despite a growing literature on couple exposure to non-persistent endocrine-disrupting chemicals and fecundability, evidence for associations between biologically measured exposures and TTP is limited. Equivocal results with different non-persistent chemical compounds and metabolites complicate the interpretation of our findings with respect to TTP, but do not preclude action, given the documented endocrine disrupting effects on other reproductive outcomes as well as fetal development. We therefore advocate for common-sense lifestyle changes in which both females and males seeking to conceive minimize their exposure to non-persistent chemicals.

SYSTEMATIC REVIEW REGISTRATION NUMBER

CRD42018084304.

The effect of pre-pregnancy hair dye exposure on infant birth weight: a nested case-control study

Background

Limited evidences were reported about the risk of pre-pregnancy hair dye use or irregular menstruation with abnormal birth weight during pregnancy, and their joint effects were also unknown. The aim of our study was to explore whether the pre-pregnancy exposure of hair dye and irregular menstruation were associated with the risk of abnormal birth weight.

Methods

We conducted a nested case-control study from a prospective cohort of 6203 pregnant women. Low birth weight study included 315 mother-infant pairs (105 LBW cases and 210 matched controls), and macrosomia study included 381 mother-infant pairs (127 macrosomia cases and 254 matched controls). Meanwhile, lifestyle information including hair dying custom and menstrual history were collected by face-to-face questionnaires and birth outcomes were extracted from the medical records. The logistic regressions models were used to analyze the join effect of irregular menstruation and hair dye use.

Results

Pre-pregnancy hair dye use was associated with increased risk of LBW (adjusted OR = 1.71, 95% CI: 1.01–2.92, P = 0.048). Irregular menstruation had high risk of LBW (adjusted OR = 2.79, 95% CI: 1.53–5.09, P = 0.001) and macrosomia (adjusted OR = 1.93, 95% CI: 1.09–3.44, P = 0.023). Additionally, in the LBW study, women who used hair dye with pre-pregnancy BMI < 18.5 kg/m² had higher OR than those with only one risk factor (3.07 vs 2.53, P_trend = 0.015), and women with both hair dye use and irregular menstruation also had higher risk than those with only one factor (4.53 vs 2.07, P_trend = 0.05). Moreover, in macrosomia study, women with irregular menstruation and pre-pregnancy BMI ≥ 24 kg/m² had higher risk than those with one factor (13.31 vs 2.09, P_trend = 0.001).

Conclusion

Our study showed that either pre-pregnancy hair dye use or irregular menstruation was associated with abnormal birth weight, especially, their joint effects could furthermore increase the risk of low birth weight infants when these two factors existed simultaneously.

Rotating shift work and menstrual characteristics in a cohort of Chinese nurses

Background

Shift work disrupts the circadian rhythm and may cause menstruation disorders. This study assessed the impact of shift work on menstrual cycle in a population of Chinese nurses.

Methods

Questionnaires on menstrual characteristics and shift schedules were sent to female nurses of the First Affiliated Hospital of Sun Yat-sen University (FAHSYSU) and Guanghua Hospital of Stomatology (GHHS), affiliated to Sun Yat-sen University. Part I was a cross-sectional study and included 139 nurses in GHHS who had regular 8:00–17:30 working (non-shift group), and 334 nurses from FAHSYSU who worked shifts, a response rate of 67.5 % and 59.6 %, respectively (age ≤ 50 years). Menstrual patterns were compared and age-adjusted relative risks of shift work were analyzed. Part II was a nested case–control study. Cases were nurses in Part I who had regular cycle with mean cycle length (MCL) of 25–31 days and but at least 3 days variation in MCL after starting shift work (n = 45). Controls consisted of 67 nurses with matching shift patterns and age, but no MCL changes. A control non-shift age-matched group consisted of 30 GHHS nurses with no MCL changes. A follow-up second questionnaire was sent 2 years later.

Results

In Part I, the shift group had a significantly higher proportion of nurses with menstrual cycle irregularity. The proportion of nurses with a cycle of 25–31 days decreased from 81.7 to 67.8 % after changing to shift work. Logistic regression analysis showed that night shift frequency was the only risk factor associated with cycle shortening. After adjusting for age, MCL was shorter when night work was performed > 7 times per month. In Part II, the mean change in MCL in the case group, including prolongation or shortening, was 4.115 ± 2.084 days after shift working. In the 2 years’ follow-up, the MCL of the study group did not recover to the original length.

Conclusions

Rotating shift work can increase the prevalence of menstrual cycle irregularity. Night shift frequency was the only risk factor associated with cycle reduced. Changes in MCL did not show recovery over a follow-up period of 2 years.

Electronic supplementary material

The online version of this article (doi:10.1186/s12905-016-0301-y) contains supplementary material, which is available to authorized users.

Reproductive disorders among cosmetologists and hairdressers: a meta-analysis

PURPOSE

Occupational risks for reproductive disorders among hairdressers and cosmetologists have been examined in numerous epidemiological studies, although the results of those studies have been inconsistent. Therefore, we conducted a meta-analysis of published studies to evaluate the risks of reproductive disorders among cosmetologists and hairdressers.

METHODS

We searched the MEDLINE, EMBASE, and Cochrane Library databases, as well as the reference lists of relevant publications, to identify studies for our analysis. After careful consideration, 19 eligible studies were included in the meta-analysis. We also performed systematic evaluations of publication bias, heterogeneity, and publication quality.

RESULTS

Study-specific odds ratios (ORs) were weighted using the inverse of their variance to calculate fixed- and random-effect pooled estimates. The meta-analysis revealed a significantly increased risk of infertility (OR 1.15, 95 % CI 1.03-1.28), fetal death (OR 1.14, 95 % CI 1.04-1.24), and preterm delivery (OR 1.04, 95 % CI 1.00-1.07) among hairdressers and cosmetologists.

CONCLUSION

These findings indicate that hairdressers and cosmetologists have a higher risk of reproductive disorders, compared to the general population.

Reproductive disorders in hairdressers and cosmetologists: a meta-analytical approach

OBJECTIVES

The aim of this study was to perform a systematic review and to use a meta-analytical approach to assess quantitatively the risk of adverse pregnancy outcomes in hairdressers and cosmetologists.

METHODS

A systematic literature search up to 1 February 2012 was carried out using major bibliographic databases, grey literature, contacts with research teams working on the subject, review papers and reference lists of selected articles. Observational studies reporting measures of effects in relation with body care (hairdressers, cosmetologists, etc.) and reproductive disorders were included. Study quality was assessed by three reviewers. The estimated risk ratios (RR) from all studies reporting on identical outcomes were combined using an average of logarithm transformation of estimated RR weighted by their inverted variance. Statistical heterogeneity across studies was assessed using Cochran's Q test. To explore the sources of heterogeneity, several sensitivity analyses and subgroup analyses were conducted based on study quality, country, study period, alcohol consumption, smoking habit, jobs and control populations.

RESULTS

Nineteen studies were selected and reviewed in-depth. The combined risk ratios (RRcs) of five reproductive outcomes were calculated and found to be significantly increased for four outcomes: time to pregnancy, which had an RRc of 1.11 (95% CI: 1.03-1.19); premature birth, which had an RRc of 1.05 (95% CI: 0.99-1.11); small for gestational age, which had an RRc of 1.24 (95 CI%: 1.10-1.41); low birth weight, which had an RRc of 1.21 (95% CI: 1.06-1.39); and embryonic and fetal losses, which had an RRc of 1.19 (95% CI: 1.03-1.38).

CONCLUSIONS

This work confirms a weak increase in risk of some reproductive disorders in female hairdressers/cosmetologists. However, the evidence level is rather weak, and a causal association between job and reproductive outcomes cannot be asserted.

Occupational chemical exposures among cosmetologists: risk of reproductive disorders

More research is needed to understand possible occupational reproductive risks for cosmetologists, specifically hairdressers and nail technicians, two occupations that often share workspace and exposure to hair dyes and nail polish. Cosmetologists are predominantly females of reproductive age; thus, they may be at higher risk for the effects of exposure to reproductive toxins. The purpose of this article is to inform nurses and public health professionals about occupational exposures for cosmetologists and discuss interventions to reduce the risks of reproductive disorders among susceptible worker populations.

Characteristics of menstrual cycle in shift workers

BACKGROUND

In this study, the characteristics of menstrual cycle in shift workers employed in the pharmaceutical industry are investigated.

METHOD

This study was conducted in a pharmaceutical industrial complex in Tehran in 2012. 406 female workers in packaging units were studied on the menstrual cycle characteristics. The studied workers were divided into two groups of shift workers and non-shift workers and were compared in terms of the frequency of menstrual disorder (short-term cycle, long-term cycle, irregular cycle and bleeding during menstrual cycle) as well as hormonal values (FSH, LH, TSH, and Prolactin).

RESULTS

The odds ratio (OR) for menstrual disorder in the shift workers was 5.54 (95% CI=2.78-11.02) compared to the non-shift workers. The mean difference of hormonal values (except prolactin) between shift workers and non-shift workers was not significant (P>0.05).

CONCLUSION

This study suggests that shift work may disrupt the menstrual cycle.

Fertility disorders and pregnancy complications in hairdressers - a systematic review

BACKGROUND

Hairdressers often come into contact with various chemical substances which can be found in hair care products for washing, dyeing, bleaching, styling, spraying and perming. This exposure can impair health and may be present as skin and respiratory diseases. Effects on reproduction have long been discussed in the literature.

METHOD

A systematic review has been prepared in which publications from 1990 to 2010 were considered in order to specifically investigate the effects on fertility and pregnancy. The results of the studies were summarised separately in accordance with the type of study and the examined events.

RESULTS

A total of 2 reviews and 26 original studies on fertility disorders and pregnancy complications in hairdressers were found in the relevant databases, as well as through hand searches of reference lists. Nineteen different outcomes concerning fertility and pregnancy are analysed in the 26 original studies. Most studies looked into malformation (n = 7), particularly orofacial cleft. Two of them found statistically significant increased risks compared to five that did not. Small for gestational age (SGA), low birth weight (LBW) and spontaneous abortions were frequently investigated but found different results. Taken together the studies are inconsistent, so that no clear statements on an association between the exposure as a hairdresser and the effect on reproduction are possible. The different authors describe increased risks of infertility, congenital malformations, SGA, LBW, cancer in childhood, as well as effects from single substances.

CONCLUSION

On the basis of the identified epidemiological studies, fertility disorders and pregnancy complications in hairdressers cannot be excluded. Although the evidence for these risks is low, further studies on reproductive risks in hairdressers should be performed as there is a high public health interest.

Pregnancy outcomes in female hairdressers

PURPOSE

The hairdressing occupation may entail exposure to a wide range of chemical products, psychosocial and physical stress. All these factors may affect the health of a pregnant hairdresser and her offspring. Our aim was to analyse whether employment in this profession is associated with adverse reproductive effects.

METHOD

Female hairdressers working in the 248 hairdressing salons in Alicante (Spain), who became pregnant for the first time after 1990 were included (n = 94). The incidence of spontaneous abortions, number of children born and their birth weight and preterm delivery among hairdressers was compared with a control group of shop assistants and office workers (n = 138). Information was collected through personal interviews at their work place. A structured questionnaire was used gathering information concerning exposure variables including the use of chemical products, ventilation at the salons, work-related stress and hours of standing work. In addition, socio-demographic factors and smoking information were obtained. Crude and adjusted relative risks (RR) and 95% confidence intervals (95%CI) were calculated using logbinomial regression.

RESULTS

Hairdressers showed a non-significant increased risk of spontaneous abortions (RR = 1.6, 95%CI 0.9-2.7). There were no differences in preterm delivery and birth weight of the children born of mothers in the two groups. Among hairdressers, the RR of spontaneous abortion among those with high perceived work-related stress was 2.4 (95%CI: 0.2-28.3) relative to those with low or normal perceived stress.

CONCLUSIONS

A slightly increased risk of spontaneous abortion among hairdressers was found, mainly associated with perceived work-related stress. Observed results deserve further research.