1 Introduction

For a long time, medical professionals considered sexuality dangerous, based on undesired pregnancies, sexually transmitted infections, sexual abuse, masturbation or what was supposed to be ‘hypersexuality’. Only in the last decades has the medical profession begun to acknowledge and accept that sexual expression has various benefits for relationships, bodies and minds.

The obstetric area showed a comparable shift in attention. In 1999, Kirsten von Sydow reviewed all English and German language articles of half a century [1]. She discovered that early research questions on sexual health were primarily negatively oriented (‘Can sex harm the baby?’), then gradually action-oriented (‘Who has intercourse during pregnancy and post-partum?’), finally going to longitudinal studies in which both partners were researched (‘How does the marital and sexual relationship develop when partners become parents?’). Cultural changes have gradually prepared the medical community to accept that sexuality can be healthy for mothers and pregnancies.

Today we are moving towards a consensus that sexual expression has multiple inherent health benefits. This chapter will look into those health benefits.

It will start with some of the general benefits. Although not directly related to pregnancy, those benefits could favour the pregnant couple. And, of course, also the private life and health of midwives, other HCPs and partners.

The second part will focus on various fertility-related benefits of sexual expression and include some relevant explanations.

‘Sexual expression’ comprises all sorts of intimate and sexual behaviour (including erotic massage, arousal, orgasm, kissing, masturbation, intercourse, etc.). Perhaps (un)necessary to mention, this chapter will only deal with the consequences of sexuality without coercion, pain or other forms of personal distress directly related to sexual activity.

The range of health benefits is comprehensive, with some benefits very short-term and directly related to the sexual act. An example is the increased pain threshold for a short period after female genital stimulation [2]. Other benefits are real long-term. For instance, the greater longevity (‘growing older’) for women who, over the years, enjoyed sexuality more and for men who, over the years, ejaculated more frequently [3].

There are many explanations for why good sex promotes good health. It is partly because good sex is an essential part of our general wellbeing, one of the prerequisites for good general health. But there are more explanations. Sexual behaviour is for a reasonable amount also physical activity, and physical activity is healthy and delays the development of atherosclerosis, various chronic diseases, cancer and cognitive decline. For young couples, they found the energy expenditure during sexual activity to be approximately 85 kcal (or 3.6 kcal/min), and on average, sexual activity is performed at a moderate intensity [4]. Even without muscular activity, sexual arousal itself activates the circulation.

Various aspects of sexual action directly influence the homeostasis of the neurotransmitters and the neuroendocrine system. Cuddling and other sexual activities increase the testosterone level; orgasm changes the prolactin level; partnered sexual activity influences the person’s immunity and stimulation of the female genitals increases the endorphin level. Oxytocin has a significant role in the reproductive triad of sexuality, birth and lactation. Caressing and massage (both touching and being touched), breast stimulation, arousal and orgasm increase the oxytocin levels. Oxytocin also has sedating and anxiolytic effects, and it can increase interpersonal trust [5]. Such influence of oxytocin is probably the reason why some men, after orgasm, fall asleep, and some others start talking.

The reader can find an extensive overview of the various benefits in a ‘White Paper’ of the PPFA [6] or more recent [7].

2 Sexuality-Related General Health Benefits

2.1 Cardiovascular Health and Longevity

In a 10-year follow-up, middle-aged men with 2 or more acts of intercourse per week had a 50% lower risk of dying than men who had intercourse once a month or less, with clear benefits in cerebrovascular and especially cardiovascular health [8]. It is probably not the act of intercourse itself but the thorough flushing of the cardiovascular and cerebrovascular system that accompanies arousal and orgasm. So, most likely other ways of reaching orgasm (including solo masturbation) are supposed to have the same benefits. A comparable explanation for the slower development of dementia is found in people with more frequent sexual activity [9].

2.2 Pain Reduction

Pain tends to be a killjoy for sexuality. However, one can also use sex as a way to reduce pain. An orgasm, for instance, diminishes migraine headaches in many female (and some male) patients. It is not yet exactly clear how that works.

Pleasurable sex can reduce pain through distraction, comparable with a romantic movie or an exciting sports match. That goes both for women and for men. For women, there is an additional sexual pathway to less pain. Pressure stimulation of the anterior vaginal wall and physical stimulation of the clitoris have an analgesic effect, with maximum impact when an orgasm is reached [2]. This increase in the pain threshold is the result of endorphins. But oxytocin seems to play a role as well. Women with higher oxytocin levels had a higher pain threshold [10]. The oxytocin increase caused by massage has anti-nociceptive effects, apparently via endogenous pain controlling systems [11].

2.3 Sexuality, Work and Marital Relationship

Employees engaging in sex at home reported increased positive effects at work the following day, both in terms of job satisfaction and job engagement [12].

2.4 Self-Esteem, Mood and Depression

Women have a higher chance of depression. Even in countries with close-to-perfect gender equality, the prevalence of depression in women is 50–100% higher than in males. It is supposed that, at least partly, this correlates with different levels of testosterone (T) and its mood-enhancing and depression-reducing action. Sexual activity itself increases the T-level both in men and women. In women (who are not on hormonal contraception), sexual thoughts also increase the T-level [13].

More sexual activity seems to be strongly connected to more happiness [14].

Self-esteem increases from positive sexual experiences with a partner and from accepting and embracing one’s own sexuality and sexual desires. More self-esteem was also found to correlate to more masturbation. Women who masturbate have a more positive body image and less sexual anxiety [15].

In 2002, American research found that women who had intercourse without a condom were less depressed [16]. Under the title ‘Does semen have anti-depressant properties?’, the article received many adverse reactions, especially concerning STI risk. Semen contains many different substances that are easily absorbed by the vaginal wall. Testosterone, DHEA and zinc are all known to have anti-depressant properties [7].

3 Sexuality-Related Reproductive and Obstetric Health Benefits

From an evolutionary perspective, one may expect that sexuality has reproductive health benefits.

3.1 Menstrual Cycle

The monthly cycles appear to become more regular in women with more frequent sexual intercourse (and in women with more frequent same-sex sexual activities) [17].

Menstrual or pre-menstrual cramps can be relieved by orgasm, apparently by opening the cervical canal. Some women use masturbation to achieve this pain-relieving effect. When they combine it with intercourse and intra-vaginal ejaculation, there is the additional benefit of the semen’s prostaglandins that assist in softening and opening the cervix.

With more frequent sex, women appear to have the intermediate-term benefit of postponing natural menopause (and the following hypoestrogenism) [18]. Ongoing sexual activity correlates with better vaginal health, especially in post-menopausal women. With frequent masturbation and coitus, there is less vaginal atrophy [19].

3.2 Fertility

‘Good sex’ is a relevant factor in conception and in maintaining a relaxed approach towards trying to conceive when success does not occur. However, professionals who counsell to couples who try to conceive, frequently tend to forget this.

A higher intercourse frequency, better arousal for the man, better arousal for the woman and proper timing of the various elements of the sexual play will together contribute to an increased conception chance. Chapter 5 will give a detailed explanation.

Recent research indicates that hormones influence menstrual-cycle-related changes in the immune response and, in that way, could influence implantation. Relevant differences in immune function have been found between sexually active women and sexually abstinent women [20].

3.3 Obstetric Advantages of Pre-conception Sexuality

The pregnant woman houses a system in which half of the tissues and antigens are paternal (from the father) and, therefore, ‘a foreign body’. Since the placenta does not keep the woman’s and the fetus’ tissues wholly separated, a limited amount of fetal cells and fluid enters the woman’s circulation (sometimes called microchimerism). After an organ transplant, we know that the human body tries to reject that foreign tissue. Gradually we are learning that some pregnancy disturbances (recurrent miscarriage and pre-eclampsia) could in some way be comparable to such ‘transplantation reaction’. That seems to depend on the amount of immunological intolerance to the tissues of the baby (in fact, to the baby’s paternal antigens). Sufficient maternal tolerance to the allogeneic fetal tissues can be developed by prior and prolonged exposure to paternal antigens in the seminal fluid, in that way protecting the fetus from rejection and facilitating successful implantation and placentation. That is where sexuality comes into the picture. For extra clarity: not semen per se, but semen of the father of the pregnancy.

In the first article on this topic, the researchers found less pre-eclampsia in women who had more experience with intra-oral ejaculation.

Women exposed to the paternal seminal fluid via absorption through the vaginal mucosa also have a lower risk for pre-eclampsia [21]. Accordingly, an increased risk for pre-eclampsia will be found (and is found) after vaginismus, after donor insemination, after a short relationship or a one-night-stand pregnancy, after being raped by a stranger and after consequent condom use (as in HIV couples).

On the other hand, women who had regular intercourse with ejaculation and without condoms will have a decreased risk. A condomless sexual intercourse period of 6 months is associated with less pre-eclampsia and less abnormal uterine activity (situations that can result in small-for-gestational-age babies [22]). It appears wise to consider such ‘sexual pre-conception recommendations’, although up to now, very few professionals discuss this with the women or the couple.

Although not researched, one may suppose that a relatively high ‘uptake’ of seminal fluid will occur after intra-rectal ejaculation, partly because of the highly vascular rectal mucosa and because an anal deposit of semen will stay relatively long in the rectum.

More recent is a study suggesting that oral sex (oral ejaculation and even more swallowing of semen) had, in a proportion of the cases, a possible protective role in the occurrence of recurrent miscarriage [23].

3.4 Sex During Pregnancy

The typical forms of sexual behaviour do not pose a risk to the pregnancy or the baby as long as the pregnancy is healthy.

Pregnant women with ≥1× weekly intercourse at 23–26 weeks had a significantly reduced risk of pre-term birth [24]. Couples who, during late pregnancy, continue intercourse have a reduced risk of pre-term birth [25]. The same goes for women who have orgasms without intercourse [26].

Still, it is important to note that pre-term birth was found more in women with trichomonas vaginalis or mycoplasma hominis when at 23–26 weeks having ‘frequent’ intercourse (≥1/week), but not when having infrequent intercourse [24]. In women with vaginal infections in late pregnancy, the male-superior position is associated with more pre-term pre-mature rupture of the membranes and more pre-mature birth [27].

When both heterosexual partners enjoyed sexual activity during pregnancy, the relationship was (4 months after the birth) evaluated as more positive in terms of tenderness and communication.

Researchers also looked at the relationship of couples 3 years after the birth. Those with mutual sexual joy before and during pregnancy had a more stable connection and were less negatively affected by the pregnancy than the couples without such mutual joy [28].

3.5 Sex and Parturition

Various elements of sexuality could contribute to the start of labour; oxytocin (via massage, breast/nipple stimulation and orgasm); prostaglandin (via semen and pounding the cervix by the penis) and uterine contractions (by orgasm). Whereas intercourse before the expected birth date did not seem to induce labour, reported sexual intercourse at term was associated with the onset of labour and reduced the need for labour induction at 41 weeks [29].

After the start of labour, the elements mentioned above of sexuality (except penetration) can keep the process going. Additional benefits are relaxation because of the pleasurable intimate contact and the increased pain threshold through elevated endorphin levels caused by genital/clitoral stimulation [2].

3.6 Long-Term Benefits

Sexuality is a significant bonding element for many couples at the start of their relationship. Then, during pregnancy, the importance of sexuality can enormously diminish for various physical, cultural and other reasons. In the first year after the birth, many women are more focussed on motherhood and the baby than on their partner, whereas many men prefer to return to their pre-pregnancy sexual pattern. Combined with the hassles of young parenthood, this can create much relationship tension, with 5% of couples divorcing after the first baby [30]. On the one hand, much of the sexual decline in post-natal relationships started during pregnancy. On the other hand, couples who continued during the pregnancy with satisfactory sex do far better after the birth [28].

4 Practical Implications

What could this list of potential health benefits teach about the role of the midwife or HCP in obstetric care?

In addition to the responsibility for a healthy mother, a healthy pregnancy and a healthy baby, we believe that good care should incorporate responsibility for healthy parenthood and healthy couplehood.

The conclusions will be evident with the parents’ dyad at risk (especially after the first pregnancy) and knowing that sexuality can be an essential disrupting factor.

  1. 1.

    Address the importance of keeping the sexual and intimate life as good as possible. An exception is when one of the partners in the couple is clearly and explicitly not interested in sexuality.

  2. 2.

    Make it clear that investing in the sexual life will help maintain or regain intimacy, sexuality and the sexual relationship after the birth.

  3. 3.

    Make it also clear that sexual activity can help to reduce stress.

  4. 4.

    Regularly explain that there are no contraindications regarding sexual expression as long as the pregnancy is without complications. In case of real disturbances, explain very explicitly what is not allowed, but also what is allowed [see Chap. 12].

  5. 5.

    When relevant, explain the potential benefits of sexual expression for pain relief, stress reduction and easier sleep.

To say it in a very simplified way: sexuality and intimacy are relevant elements of care.