A Close and Supportive Interparental Bond During Pregnancy Predicts Greater Decline in Sexual Activity From Pregnancy to Postpartum: Applying an Evolutionary Perspective

A Close and Supportive Interparental Bond During Pregnancy Predicts Greater Decline in Sexual Activity From Pregnancy to Postpartum: Applying an Evolutionary Perspective. Tierney K. Lorenz, Erin L. Ramsdell and Rebecca L. Brock. Front. Psychol., January 10 2020. https://doi.org/10.3389/fpsyg.2019.02974

Rolf Degen's take: https://twitter.com/DegenRolf/status/1343508745897259009

Abstract: A common topic for advice given to parents after childbirth – both from relationship experts and popular media – is how to “bounce back” to one’s pre-pregnancy sexuality, with warnings that postpartum declines in sexual frequency will take a serious toll on one’s relationship. However, these admonishments may not accurately reflect the ways in which the unique reproductive context of pregnancy and the postpartum transition alter associations between sexual frequency and relationship quality. Evolutionary perspectives on reproductive strategies would suggest that in the postpartum context, decreased sexual activity would help target parental investment in the current offspring (rather than creating new offspring); however, if the parental relationship is lacking in intimacy and support, continued sexual activity may help seal the cracks in the bond. We tested this theory in a longitudinal dyadic study of changes in relationship quality and sexual frequency from pregnancy to 6 months postpartum among 159 heterosexual couples. We found that across three different measures of relationship quality taken from interviews and behavioral observation of couple interactions, higher relationship quality (i.e., greater support, intimacy, and responsiveness) predicted greater decline in sexual frequency whereas sexual frequency remained relatively stable in lower quality relationships. These findings suggest that, during the postpartum transition, decreased sexual frequency may not be a reliable signal of poor relationship quality.

Discssion

Discussion of Main Findings

The transition to parenthood can be both exciting and confusing, presenting both parents with the challenges of adopting new roles and new ways of relating to each other while supporting their child. Sexuality and intimacy can take on new meaning during this transition, leaving many parents wondering what is normal and what might signal problems ahead. We followed couples during pregnancy and 6 months postpartum, measuring changes in their frequency of sexual activity and relationship quality using multimodal measures. Those couples who reported greater emotional closeness and responsiveness in their relationship during pregnancy had a greater decline in sexual frequency than those who reported less intimate and synchronous relationships. Notably, when considering the impact of partner support on changes in sexual frequency, there were gender differences. Specifically, there were greater declines in sexual frequency when mothers received higher quality support from their partners whereas decline in sexual frequency was predicted by fathers receiving poorer quality support. Interestingly, the aforementioned patterns remained significant even when considering the impact of sexual problems on sexual frequency.

While at first glance it may seem surprising that higher interparental relationship quality is associated with greater decline in sexual activity, this finding fits predictions from evolutionary models of close relationships during an important reproductive transition. The decline in sexual frequency observed in couples who had closer bonds may reflect a positive adaptation, delaying further investment in new offspring (Gray, 2013; Rupp et al., 2013), and reducing potential costs of postpartum sex such as infection or pain (Lehtonen et al., 2012). When the couple has a strong and trusting bond, their energy can be directed at navigating the challenges of parenthood: sex can take a back seat for a little while. But when new parents perceive a lack of intimacy and responsiveness, then they may turn to sex as a means of shoring up their troubled bond (Magginetti and Pillsworth, 2019). This is reflected in the relatively higher number of pregnant and postpartum women who report engaging in sex for relationship maintenance reasons than for sexual desire or pleasure reasons (Gerda et al., 2006; Bello et al., 2011; Hipp et al., 2012; Sagiv-Reiss et al., 2012).

In particular, when new mothers perceive a lack of support from their male partners, they may engage in sex more frequently to renew paternal investment in both the relationship and the offspring. Indeed, other studies have suggested that when there are threats to the relationship (such as perceptions of other women flirting with their husband), pregnant women’s sexual desire for their partner paradoxically increases (Magginetti and Pillsworth, 2019). Insofar as sexual activity represents a possible investment in a new child, while decline in sexual frequency signals the need to consolidate resources in the current offspring, we would expect different patterns in mothers versus fathers based on their relative investment in reproduction more generally. Indeed, we saw some evidence of gender differences in the association between perceived support and decline in sexual activity. Simply put, fathers have (relatively) more leeway in the degree of support they provide, and the investment they make during the postpartum period (Gray, 2013). Accordingly, when support received by mothers is of poor quality, mothers may have to negotiate greater support by engaging in more sexual activity; when support received by mothers is of high quality, she can afford to redirect her energies to her offspring. On the other hand, when mother’s support of the father is of low quality, he will likely not improve her support by seeking more sex: if anything, this would further tax the mother’s resources and make her less inclined to provide him support.

Most previous research on intimate relationships has taken the perspective that decline in sexual frequency is a negative outcome, and would be expected in relationships that are less intimate, supportive, and mutually responsive. However, our findings suggest quite the opposite when a couple is caring for a newborn. At a proximal level of analysis, this contrast is likely tied to the different factors that lead to lower sexual frequency in parents and non-parents: whereas non-parents are mostly likely to report declining sexual frequency stemming from relationship conflict and sexual dysfunction (Laumann et al., 1999; Sprecher et al., 2004), parents navigating the postpartum period are more likely to cite fatigue (Ahlborg et al., 2005; Hipp et al., 2012), lack of time, and concerns about causing harm to the mother’s body after childbirth (Schlagintweit et al., 2016; Beveridge et al., 2018). In other words, the negative effects of decline in sexual frequency may be buffered by perceptions that the decline is situational and temporary (Vannier et al., 2018), and feeling that avoiding sex is an expression of care and commitment to one’s partner. For example, in one study, mothers who reported their partner was understanding of their need to avoid or delay sex had significantly higher relationship and sexual satisfaction (Muise et al., 2017). Another proximate mechanism may be cognitive dissonance. That is, it is possible that couples with lower relationship quality may engage in more frequent sex even after the postpartum transition, in order to resolve the psychological stress of being committed to a less intimate and supportive relationship, when they are forced into this commitment by virtue of having to rely on each other to care for the newborn.

Discussion of Secondary Analyses

We also examined how relationship quality predicted change in sexual frequency in women with and without sexual problems, and found no significant difference between these groups. In non-parenting contexts, relationship quality and sexual dysfunction often interact to predict declines in sexual frequency: when relationship quality is good, sexual dysfunction may or may not result in lower rates of sexual activity (Schoenfeld et al., 2017) but when relationship quality is poor, sexual function is strongly associated with sexual frequency (Litzinger and Gordon, 2005; Hayes et al., 2008). However, in the present study, including mother’s sexual problems in the model did not alter the associations between relationship quality and changes in sexual frequency during the postpartum transition. As with all null effects, it is important not to over-interpret the lack of an observed significant effect; it is possible that this analysis was underpowered to detect small, but potentially meaningful, effects. However, it is also possible that in the postpartum context, changes in sexual function may be more independent of relationship factors (Hansson and Ahlborg, 2012). Although a large number of studies have shown declines in sexual function in pregnant and postpartum mothers (see Jawed-Wessel and Sevick, 2017; McBride and Kwee, 2017 for reviews), these declines may be less related to relationship conflict and more closely aligned with other factors such as changes in the mother’s body [e.g., vascular changes in the vagina and clitoris following pregnancy (Battaglia et al., 2018) or perineal injury (Signorello et al., 2001)], hormonal factors [e.g., increased prolactin during breastfeeding (LaMarre et al., 2003)], fatigue (Schlagintweit et al., 2016), and pre-pregnancy sexual dysfunction (Yıldız, 2015). Taken together, these findings suggest that lower sexual functioning among parents of newborns may be less diagnostic of relationship problems than a consequence of the physical and lifestyle changes associated with parenthood.

Clinical and Theoretic Implications

Our findings have several important clinical and theoretic implications. Firstly, when counseling parents on the resumption of sexual activity following childbirth, providers should consider setting expectations that a decline in sexual frequency is common, even more so among healthy couples. This is not to say that couples should be counseled to avoid sexual activity per se, but rather not to interpret decline in sexual frequency as a harbinger of larger relationship difficulties. New mothers in particular appear to be concerned about how changes in the sexual relationship will impact their partners (Schlagintweit et al., 2016), and may benefit from her partner’s encouragement to communicate when she needs to take a break from sex (Muise et al., 2017).

More broadly, these findings suggest that the reproductive context may change the nature of the association between interparental relationship dynamics and sexual activity. An important follow-up to the present study will be to investigate the tipping point at which the effect reverts, and low sexual frequency again signals relationship problems. If our hypothesis is correct, and the decline in sexual frequency follows the need to reallocate resources to a vulnerable offspring, we should expect sexual frequency to rise as the child grows and requires less direct parental support. If sexual activity does not resume even after the reproductive context shifts back to fertility, it may at that time indicate relationship strain. Additionally, as lactation is one of the strongest signals to the mother of the infants continued need for support (Vitzthum, 1994), we may expect that the tipping point will occur later for breastfeeding vs. bottle-feeding mothers.

Moreover, if the postpartum decline in sexual frequency reflects an adaptive response, temporarily shifting reproductive investment to the current offspring, we must question how we consider sexual desire within the construct of postpartum depression. Specifically, our findings call for the need to consider the reproductive context in which low desire occurs in order to determine if it contributes to evidence of psychopathology. Certainly, low sexual desire is common among postpartum depressed mothers (Khajehei et al., 2015) – but as it is common among healthy postpartum women as well (Chivers et al., 2011), the symptom may lack discriminant validity in this context.

Limitations

While this study had significant strengths, including a longitudinal design and multimodal, dyadic measurement of both relationship quality and sexual frequency, there are some limitations worth noting. Participation in this study was limited to mixed-sex (heterosexual) couples, and thus the effects in same-sex couples, or non-dyadic parental structures (e.g., poly families) remain unclear. Future study of sexuality within non-traditional family structures will improve generalizability as well as contribute to the understanding of the evolution of alloparenting (Bogin et al., 2014). The present study sample was mostly White and middle class. Both minority stress and socioeconomic status are likely to increase the strength of the effects we observed: insofar as the postpartum decline in sexual frequency represents a rebalancing of resources from potential future offspring to the current offspring, we should expect stronger effects as couples are put under greater stress or financial hardship.

Our measure of sexual frequency was limited to partnered sexual activity; while this does not change our ability to test our main hypotheses, future studies may benefit from teasing apart changes in sexual activity (including solitary sexual activity) from changes specific to the sexual relationship. Similarly, we focused on mother’s sexual problems, as there was greater prior research on changes in women’s sexual function during pregnancy and postpartum; however, future work may benefit from consideration of changes in paternal sexual function as well. Also, our measure of sexual problems came from holistic participant self-report, which may or may not have included explicit discussion of sexual satisfaction or distress regarding their sexual problems. As noted above, this means that we cannot conclude these sexual problems would meet clinical criteria for a sexual dysfunction, as distress is a crucial element of the diagnosis. More precise measurement of sexual functioning and relationship satisfaction, which prompts participants to consider their distress, may reveal subgroups for whom sexual problems are a more significant moderator.

Finally, in interpreting these findings, it must be noted that we were primarily interested in the constructs most closely related to how the interparental relationship contributes to potential offspring survival, and as such we focused on indices of support, responsiveness, and intimacy rather than relationship satisfaction or happiness. There is a broad literature documenting declines in sexual and relationship satisfaction during the postpartum transition (see Mitnick et al., 2009 for review and meta-analysis), and their association with decline in sexual frequency (Schlagintweit et al., 2016; Rosen et al., 2018). While the link between relationship satisfaction and offspring survival is more indirect, it is certainly worth investigating if and how the present evolutionary framework may explain how longitudinal changes in parental attitudes toward the relationship map onto changes in sexual frequency.