Combining breastfeeding and work: findings from the Epifane population-based birth cohort

Breastfeeding (BF) initiation has been shown to be insufficient, and mean BF duration falls under the recommended 6-month duration in most developed countries, despite its acknowledged benefits and public health actions [1]. Among several determinants, increasing attention has been paid to return to work (RTW) as a major constraint to initiate and continue BF [2‐4]. Numerous previous studies consistently concluded that RTW before 12–16 weeks, compared with later or not at all, was associated with shorter BF duration [5‐15]. Indeed, women themselves mentioned RTW as a reason for stopping BF [16‐20], though not in all settings [21, 22], probably due to cultural norms and work support backgrounds. Moreover, women who planned to work after giving birth often did not begin BF, by anticipation. However, conclusions between studies are inconsistent [2, 7, 11‐13, 23‐27]. Methodological weaknesses, i.e. cross-sectional design or inaccurate data collection, limit our understanding of mechanisms involved in this phenomenon [28]. In addition, a potential bilateral relationship makes it difficult to interpret causality direction. Use of RTW as the outcome, and taking into account its confounders, could help to gain better insight into the complex relationship between BF behavior and RTW.

Although the relationship between RTW and BF cessation has been frequently examined, the combination of BF and work has rarely been studied in the general population [29, 30]. This type of behavior could be a strategy for encouraging BF and its duration. Solutions such as teleworking, flexible working hours and access to a room available for BF or for pumping milk would act as motivations for women to continue BF after RTW [30, 31]. Nevertheless, along with workplace conditions, characteristics of women who successfully combined BF and work have thus far been rarely described in Western countries.

Our objectives were to study the time span during which women employed prior to pregnancy returned to work according to BF duration category, and to identify sociodemographic, behavioral and pregnancy characteristics of women who continued BF after returning to work. This research was carried out in France, where most women have access to paid maternity leave, usually lasting around 12 weeks.

A total of 3368 women were included in the Epifane cohort. Analyses regarding time of RTW were carried out in the 2480 women who worked prior to pregnancy. Characteristics associated with a combination of ABF and work were analyzed in the 1487 women who had worked before pregnancy and who returned to work within a year after delivery.

In our study carried out in France in 2012, eight out of ten employed women returned to work within a year, at a median of 5.3 months. We showed that no BF and ABF durations shorter than 4 months were associated with similar trends in RTW. Only women who breastfed for over 4 months returned to work at a later time. Furthermore, among breastfeeding women who returned to work within a year after delivery, one-third combined ABF and work. Birthplace, occupation, smoking status and mode of delivery were independently associated with combined ABF and work.

Comparison with other studies is limited due to variable durations of follow-up and different methods used to assess BF and work status. In our study, we used prospective repeated phone interviews for a one-year period to collect detailed information on infant feeding, which was the primary goal of the Epifane cohort [32]. In other studies using cross-sectional investigation, BF practice assessment was likely to lead to memory bias, especially when the interview was distant from the period in question. In contrast, we collected sparsely detailed information on work conditions after delivery. Other authors examined working status before pregnancy [21, 35], intention to return to work (not necessarily followed up) [9, 11, 23, 36], and various categories of time spans before RTW [6, 8‐10, 15, 24]. In addition, groups of reference may have included mothers working before pregnancy, or not working at all, thereby affecting interpretation. In our study, we analyzed women who worked before pregnancy, enabling a more accurate interpretation. Moreover, since the RTW span is highly variable, it was considered here to be the outcome in survival analysis, thus enabling us to consider its potential determinants.

In our study, consistent with previous findings in other cohorts [8‐10], ABF longer than 4 months was associated with a RTW 2 months later than for no ABF. It is difficult to determine whether women continued ABF because they were given the opportunity not to return to work before 4 months, or whether they chose to return to work later because they wished to breastfeed longer [37]. Nevertheless, Kaplan-Meier curves show no clear break at the end of the minimal legal maternity leave in France (12 weeks). In reality, paid maternity leave may vary under different circumstances, including legal provisions, i.e. shorter than 12 weeks for women who are self-employed, longer for women who have twins, a third pregnancy or major medical complications, women who postpone part of the prenatal leave after birth or who take annual leave, or have other favorable conditions agreed upon with their employer. The French situation is not transposable to all settings, which depend on the legal environment [2]. In-depth interviews are needed to better understand how work constraints influence the individual decision to breastfeed.

Another insightful finding was RTW time statistically comparable between women who did not breastfeed at all and those who breastfed for less than 4 months. Therefore, we hypothesize that BF initiation may not necessarily be dependent on a planned RTW [2, 36]. Determinants of BF initiation other than planned RTW should therefore be taken into account. For instance, pregnancy complications are considered to be strong determinants of BF initiation [4, 38], but they did not affect the RTW time in our study. “Farmwomen, artisans and merchants” were likely to return to work much earlier, but they were also more prone to breastfeeding for a longer duration. Flexibility in working hours therefore appears to be a key determinant in BF initiation and continuation [30]. In addition to occupation, full-time or part-time work status may also be a decisive factor, as shown in previous studies [39, 40]. Such information was not available here, and our goal was to identify general characteristics of women who combined BF and work.

Indeed, women who combined BF and work showed significant specificities. First, exclusive BF since birth and on demand (loosely based on the number of feeds and on where the child slept) (Table 3) might augment the possibility of continuing BF after RTW. Second, self-employed women who may have some flexibility (“Farmers, artisans and merchants”) were most likely to continue BF. In contrast, manual workers and “intermediate employees” (i.e. with subordinate positions) were less likely to be able to continue ABF [41]. In an intermediate situation, and despite early RTW and other working constraints, managers may have continued ABF because it was compatible with their work organization and also because of the health benefits they expected for their child. The fact that, in our study, women who continued to breastfeed after RTW were more likely to be non-smokers before pregnancy also underlines a potentially higher degree of health awareness.

Though they were less likely to return to work within the child’s first year, women born outside of France were more likely to combine ABF and work, regardless of other co-variates. Birthplace abroad was previously highlighted as a prominent BF determinant in developed countries [42]: community norms and dissemination across generations may account for such findings. Thus, ABF behavior of foreign women who return to work would appear to be influenced by such conditions. The manner in which they succeed in combining ABF and work could help in developing actions destined for native-born mothers.

The primary objective of the Epifane cohort was to describe infant feeding during the first year of life. We therefore collected extremely detailed information [32]. However, information related to maternal working conditions is more limited, as underlined above. Moreover, though a large set of co-variates was taken into account, we cannot rule out residual confounding in the relationship between BF duration and RTW time, such as breastfeeding intentions, encouragement for breastfeeding (from the family, etc.), and income, which were not collected in this cohort. In addition, due to the short duration of exclusive BF in France, its specific analysis was not carried out, although this represents a target to be attained. Finally, despite strict instructions given to interviewers not to influence mothers, repeated questions on BF may have modified related behavior and yielded an overestimated percentage of women combining ABF and work. Finally, our results require confirmation by further studies in other settings.

Our findings may have important consequences for BF promotion. In contrast to generally held ideas, RTW does not necessarily prevent BF initiation or continuation, although this phenomenon is measurable only for BF duration of less than 4 months. Moreover, only one-third of women succeeded in combining work and BF. Indeed, working conditions, as described in our study via occupational categories, would appear to be of crucial importance. Finally, much improvement is needed in research, and at the public health level, so as to include widespread dissemination of information directed toward women who wish to continue breastfeeding after returning to work.