Female sexual function and distress and time-to-pregnancy in a prospective preconception cohort

Abstract

Background:

Fertility success among mixed-sex couples often depends on frequency and timing of sexual intercourse, yet little research has evaluated the association between preconception sexual function and time-to-pregnancy (TTP).

Objective(s):

To evaluate the effects of female sexual dysfunction, distress related to sexual functioning, and painful intercourse on TTP.

Study Design:

We followed 2,500 participants from Pregnancy Study Online (PRESTO), a prospective cohort study of self-identified females attempting pregnancy without the use of fertility treatments. Participants enrolled between 2021 and 2024. Thirty days after enrollment, participants completed a supplemental questionnaire that contained questions about sexual health, including a modified version of the 6-item Female Sexual Function Index (score range 2–30, score ≤19 defined as sexual dysfunction) and the Female Sexual Distress Scale (score range 0–48, score ≥20 defined as clinically-relevant distress), which assess experiences in the previous 4 weeks. Participants completed the supplemental questionnaire no later than 6 months after initiating conception attempts. We estimated TTP based on self-reported pregnancy status on follow-up questionnaires completed every 8 weeks for up to 12 months. We used proportional probabilities regression to calculate fecundability ratios (FRs) and 95% confidence intervals (CIs) relating exposure measures with TTP, adjusting for a range of pre-specified confounders. As an exploratory analysis, we evaluated individual domains of sexual function (i.e., interest, arousal, orgasm, lubrication, and satisfaction) in relation to TTP.

Results:

The study population was primarily non-Hispanic White, high income, with college or graduate education. Exposure prevalence was 20.1% for female sexual dysfunction, 8.8% for distress, and 29.6% for any pain with intercourse. We observed no association between FSD and TTP (adjusted FR 1.00, 95% CI 0.890, 1.13) when FSD was defined using a clinically-validated cut point, but observed that those in the first, second, and third quartile of scores had delayed conception compared to those in the fourth (highest function) (adjusted FRs 0.90, 95% CI 0.76, 1.06; 0.88, 95% CI 0.75, 1.04; and 0.90, 95% CI 0.77, 1.04, respectively). We found 18% reduced fecundability among those with sexual distress as defined by a clinically-validated cut point compared to those without (adjusted FR 0.82, 95% CI 0.69, 0.98). Participants reporting painful intercourse most or all the time had a longer TTP than those reporting no pain (adjusted FR 0.81, 95% CI 0.62, 1.06). In exploratory analyses, lower function in orgasm and lubrication domains, but not interest, desire, and arousal, were associated with longer TTP.

Conclusion(s):

Preconception sexual dysfunction, specifically distress and frequent painful intercourse, was associated with delayed conception. Preconception clinical assessment of sexual function, including discussion of individual domains of sexual function, may elucidate important modifiable issues.

Tweetable statement:

Lower sexual function, higher distress related to sex, and frequent painful intercourse were associated with longer time to pregnancy.

Introduction

Female sexual dysfunction (FSD) is characterized by an impaired ability to participate in or enjoy sexual activity accompanied by personal distress.¹ FSD manifests across different domains, including sexual arousal/desire, orgasm, lubrication, and pain.¹ Sexual dysfunction is associated with reduced quality of life^2–4 and bidirectionally associated with poorer mental health⁵ and lower relationship and life satisfaction.^6,7

Sexual function is relevant for conception among mixed-sex couples not using fertility treatment because frequency and timing of sexual intercourse affect time-to-pregnancy (TTP).⁸ While infertility has been shown to impair sexual function,^9–16 little research has evaluated the role of sexual function in TTP. In a Singaporean study of pregnancy planners, lower female sexual function was associated with prolonged TTP, though the authors did not use an externally-validated definition of sexual dysfunction.¹⁷ Because sexual function issues (e.g., painful intercourse) are prevalent in the preconception period¹⁸ and healthcare providers do not routinely discuss sexual function with patients,^18,19 sexual dysfunction may be an under-recognized cause of prolonged TTP.

Our objective was to assess the effects of sexual dysfunction and distress on TTP in a North American cohort of pregnancy planners. We also separately evaluated individual domains of female sexual function in relation to TTP.

Methods

We used data from Pregnancy Study Online (PRESTO), an ongoing web-based prospective cohort study.²⁰ PRESTO enrolls female-identified participants attempting pregnancy with a male partner who reside in the United States (US) or Canada, are not using fertility treatments or contraception, and are aged 21–45 years. Recruitment occurs via online advertising, posted flyers, and word of mouth. Participants complete online questionnaires at enrollment and every 8 weeks for up to 12 months or until pregnancy occurs, whichever comes first. In March 2021, we added the Sexual Health and Well-Being Questionnaire (SHQ) to the PRESTO protocol. This optional questionnaire asks about participants’ sexual health and feelings about their sex life. All former and already-enrolled participants received an email inviting them to complete the questionnaire. Participants who enrolled after SHQ launch were invited via email 30 days after enrollment, though completion was possible any time after enrollment. Approximately 60% of prospectively-enrolled participants completed the SHQ.

Research suggests that declines in sexual function begin after 6 months of conception attempts;¹⁸ thus, we restricted our sample to those who completed the SHQ no later than 6 months after their self-reported conception attempt initiation to reduce the risk of reverse causation (see Figure 1).

Figure 1. Cohort creation from Pregnancy Study Online (PRESTO), 2021 – 2024.

Flow chart depicting creation of analytic cohort

The study protocol was approved by the Boston University Medical Campus Institutional Review Board, and participants provided informed consent online.

Exposure assessment

Sexual dysfunction and distress were ascertained using two validated scales included in the SHQ. Participants answered a modified version of the 6-item Female Sexual Function Index (FSFI-6) scale, a clinically validated instrument designed to identify FSD.²¹ The FSFI-6 is a reduced version of the 19-item Female Sexual Function Index²² which asks participants to assess their sexual function over the past 4 weeks across six domains: interest, arousal, lubrication, orgasm frequency, pain, and satisfaction. Responses to all questions were collected via a Likert scale ranging from 1 (lowest function) to 5 (highest function). We replaced the original FSFI-6 lubrication question (i.e., how often did you become aroused during sexual activity?) with the question ‘Over the past 4 weeks, how difficult was it to become lubricated (“wet”) during sexual activity or intercourse (only consider lubricant your vagina produces, not use of bottled lubrication)?,’ drawn from the full Female Sexual Function Index,²² which we perceived as more specific. In a small validation study of 291 participants who completed both questions, the Pearson correlation coefficient was 0.79. Our replacement question (lubrication difficulty) had slightly higher mean responses than the original question (lubrication frequency) (4.11 vs 4.00).

Participants who reported no sexual activity (n=23) or no sexual activity or intercourse (n=28) in the past four weeks received a score of zero on questions requiring activity, as previously described.²¹ We summed scores (possible scores ranging from 2 to 30) and assigned those with a score ≤19 as having FSD, consistent with prior research.²¹ We also defined quartiles based on the distribution of scores in the sample. To reduce the potential for false positives due to transient pain, we asked participants if they had experienced an infection (e.g., yeast infection) causing vaginal pain in the previous 4 weeks. We reassigned those reporting an infection and meeting the threshold for FSD as not having FSD (resulting in the reclassification of N=15, 0.6%).

We assessed sexual distress using the Female Sexual Distress Scale (FSDS),²³ a 12-item measure that assesses feelings related to sex in the past 4 weeks. Responses were on a Likert scale that ranged from “never” (assigned a value of 0) to “always” (value of 4). We summed responses (possible range of 0–48), used a score ≥20 as the cutoff for clinically relevant sexual distress,²³ and calculated quartiles.

We used a single question from the FSFI-6 to assess painful intercourse: “Over the past 4 weeks, how often did you experience discomfort or pain during vaginal penetration (intercourse)?” Response options included “Did not attempt vaginal penetration,” “Almost never or never,” “A few times,” “Sometimes,” “Most times,” or “Almost always or always.” For these analyses, we excluded participants who did not attempt vaginal penetration in the past 4 weeks (n=56) and those who reported the presence of an infection which caused pain (n=79). We categorized those who reported that they experienced pain “A few times” or more frequently as having pain with intercourse. We additionally created a three-level variable for experiences of painful intercourse in which the categories were “Always, almost always, or most times,” “Sometimes,” and “Never, almost never, or a few times.”

Outcome assessment

We calculated TTP using data from baseline and follow-up questionnaires. At baseline, participants reported the date of their last menstrual period (LMP), usual menstrual cycle length, and the number of menstrual periods they had since they initiated conception attempts. At follow-up, participants again reported LMP date and whether they had conceived since the previous questionnaire. Usual cycle length for participants reporting irregular cycles was calculated using baseline LMP and consecutive LMPs reported on follow-up questionnaires. We calculated total pregnancy attempt time based on the total discrete cycles at risk of pregnancy using the following formula: cycles of attempt at study entry + [(LMP date from most recent follow-up questionnaire – date of baseline questionnaire completion)/usual cycle length] + 1.

Covariates

Covariates were ascertained via-self report on the baseline questionnaire. They included history of diagnosed medical conditions (endometriosis, polycystic ovarian syndrome, diabetes, depression, anxiety, post-traumatic stress disorder, and a history of any sexually transmitted infection or fibroids), age (<25, 25–29, 30–34, 35–39, ≥40 years), marital status (married, unmarried), body mass index (BMI) (<18.5, 18.5–24, 25–29, ≥30 kg/m²), measures of current socioeconomic status: education (≤high school, some college, college, graduate school), annual household income (<$50,000, 50,000–99,000, 100,000–149,000, ≥150,000 USD), health insurance coverage (private insurer, other), race/ethnicity (Non-Hispanic Asian, non-Hispanic Black, Hispanic/Latina, Mixed/other race, non-Hispanic White), employment status (employed, unemployed), employment factors including average hours worked per week and past-month rotating shifts or work at night, behavioral factors including average alcoholic drinks consumed per week, cigarette smoking status (never, former, current), any cannabis use in the past 4 weeks, and sleeping on average <7 hours per night in the past 4 weeks. We estimated physical activity levels by asking participants to report the average hours per week spent engaging in a number of different activities in the past year which were then used to calculate the average metabolic equivalent (MET) hours per week and categorized as <10, 10–19, 20–39 and ≥40.²⁴

We assessed general stress using the 10-item version of the Perceived Stress Scale,²⁵ categorized as <10, 10–19, 20–29, and ≥30. Reproductive factors included a history of live birth, and whether participants had ever tried unsuccessfully to conceive for 12 months (history of infertility). Participants reported on intercourse frequency via the question “In the past month, about how often did you have sexual intercourse with your partner (your partner’s penis inserted into your vagina)?” and categorized as <1, 1, 2–3 or ≥4 times per week. Intercourse frequency was identified as a potential mediator, and thus was not included in adjusted models.

Some covariate information was collected on an optional supplemental questionnaire, which participants were invited to complete 30 days after enrollment. Respondents answered to a question from the Brief Trauma Questionnaire:²⁶ “Has anyone ever made or pressured you into having some type of unwanted sexual contact?” with the responses ‘Yes,’ ‘No,’ or ‘Don’t know.’ Responses for who responded ‘Don’t know’ were imputed. Participants also responded to two questions related to their perception of their relationship in the past year, specifically “To what extent did your partner show you love and affection?” and “To what extent could you count on your partner to provide you with emotional support?” Responses were categorized as ‘never/rarely’, ‘some of the time,’ ‘most of the time,’ ‘all of the time.’ Fifty-nine participants in our analytic dataset did not complete this supplemental questionnaire; their responses were multiply imputed.

Analyses

We calculated age-standardized baseline characteristics stratified by sexual dysfunction, sexual distress, and painful intercourse. We used proportional probabilities regression models to estimate fecundability ratios (FRs) and 95% confidence intervals (CIs) for associations between each exposure and fecundability.²⁷ The FR compares the average per-cycle probability of conception in exposed and unexposed participants. Participants contributed at-risk cycles from cohort entry until pregnancy or a censoring event (i.e., initiation of fertility treatment, cessation of pregnancy attempts, study withdrawal, loss to follow up, or 12 cycles of unsuccessful conception attempts), whichever occurred first. Participants who entered the study with ≥1 cycle of attempt time contributed cycles at risk beginning with their first cycle under observation (i.e., the first cycle at risk contributed to the analysis for those with 2 cycles of attempt time at study entry was cycle 3).

We selected potential confounders using a directed acyclic graph (DAG)²⁸ (see Supplemental Figure 1) informed by published literature.^18,29–39 A DAG is a visual depiction of the relationship under study, including factors associated with the exposure and outcome, that informs the selection of adjustment covariates.²⁸ For the primary analysis, we calculated crude FRs, age-adjusted FRs, and FRs adjusted for all prespecified confounders (listed above). For pain-related exposures, we calculated additional models where we omitted psychosocial confounders potentially less relevant to physiological causes of pain (current employment, hours worked per week, shift work, work at night, short sleep duration, marital status, and physical activity).

Missing data

Missing data were minimal (<5%). We imputed missing values for questions in the FSFI-6 and FSDS and covariates using fully conditional specification methods to create 20 imputed datasets.⁴⁰ We assigned those without any follow-up information (2.3%) one cycle of follow-up and multiply imputed their pregnancy status (yes vs no). Missingness for all variables is displayed in Supplementary Table 1.

Inverse probability of treatment weighting

Participation bias may have occurred because not every PRESTO participant completed the SHQ.⁴¹ We used inverse probability of treatment weighting (IPW) to account for this bias, adjusting for factors related to response and TTP. For more details, please see Appendix I.

Exploratory and sensitivity analyses

To explore the shape of the association between sexual function and distress with TTP, we fit restricted cubic splines for the continuous modified FSFI-6 and FSDS scores adjusting for all prespecified confounders. We also created three-level variables for the five individual sexual function domains besides pain (interest, arousal, lubrication, orgasm, and satisfaction) in which we grouped the highest two and lowest two categories, respectively, into a ‘high’ and ‘low’ function group and evaluated the association between each individual domain and TTP.

We conducted an exploratory analysis to investigate the role of partner sexual function (see details in Appendix II). To reduce the potential for reverse causation and selection bias due to left truncation,⁴² we repeated the primary analysis restricting the sample to those who had ≤3 cycles of conception attempts at the time of SHQ completion.

Interpretation

As recommended by the American Statistical Association, we interpreted our findings based on the magnitude, direction, and precision of the effect estimates, as opposed to binary significance testing,.⁴³

Results

Age-standardized baseline characteristics for the sample (N=2,500) are displayed in Table 1. Participants enrolled between 2021 and 2024. Means and percentages of evaluated characteristics are standardized to the sample age distribution at baseline (in categories), to facilitate a qualitative assessment of differences in characteristics across exposures after accounting for differences in age. Most of the sample was aged 25–34 years, married, and nulliparous. Over 80% of participants had at least a college degree and over half of the participants reported an annual household income of at least US$100,000. Over 80% of the sample identified as non-Hispanic White. Sexual function issues were more common among those with a history of depression, anxiety, a history of infertility, and greater self-reported stress. Those with sexual function issues reported less frequent intercourse (Supplementary Figure 2). Exposure prevalence was 20.1% for FSD (modified FSFI-6 score ≤19), 8.8% for distress (FSDS ≥20), and 29.6% for any pain with intercourse.

Table 1.

Age-standardized^a characteristics at enrollment by three sexual function exposures among 2,500 PRESTO participants, 2021–2024

	Sexual dysfunctionb		Sexual distressc		Any painful sex in the past 4 weeksd
Characteristic	Yes (N=502)	No (N=1998)	Yes (N=219)	No (N=2281)	Yes (N=700)	No (N=1665)
Cycles of conception attempts at completion of sexual function questions, %
0	7.1	7.4	5.5	7.5	7.8	7.2
1	23.7	27.3	27.8	26.4	24.7	26.8
2	25.3	26.6	22.4	26.8	27.8	26.1
3	17.0	14.8	16.2	15.1	16.8	14.7
4	12.4	12.5	12.0	12.5	11.7	12.7
5	12.3	9.9	13.8	10.0	9.7	10.7
6	2.2	1.5	2.3	1.6	1.6	1.6
Age (years), mean	31.8	31.2	31.2	31.3	30.9	31.4
Age, %
<25	2.4	3.7	4.6	3.3	5.1	2.5
25–29	23.3	29.4	26.5	28.4	30.1	27.7
30–34	50.6	49.3	47.0	49.8	49.7	50.0
≥35	23.7	17.6	21.9	18.5	15.0	19.9
Alcohol consumption (drinks/week), mean	2.5	2.6	2.6	2.5	2.5	2.5
Hours worked per week, meane	34.5	34.8	32.2	35.0	35.1	34.5
History of infertilityf, %	6.5	4.2	7.4	4.5	6.1	3.9
Parous, %	33.6	30.5	35.4	30.6	33.6	29.9
Interpregnancy interval (months; among parous), %
≤12	12.6	9.8	10.6	10.2	11.0	9.7
13–47	17.8	15.8	18.8	16.0	17.7	15.9
≥48	2.1	4.6	4.7	4.0	4.4	3.8
Smoking status, %
Current	2.0	1.9	3.6	1.9	2.4	2.0
Former	6.0	7.5	9.2	7.0	7.6	7.0
Never	92.0	90.6	87.2	91.2	90.0	91.1
Any cannabis use in previous 4 weeks, %	16.3	19.1	21.6	18.2	16.5	19.6
Participant education, %
≤High school	1.8	1.4	2.5	1.5	1.0	1.8
Some college	8.4	9.3	14.4	8.7	8.2	9.5
College degree	32.5	31.2	28.4	31.7	31.6	31.4
Graduate school	57.4	58.0	54.7	58.1	59.2	57.4
Income, USD %
<$50,000	8.6	7.5	11.2	7.4	8.9	6.8
$50,000–99,000	20.9	22.2	28.4	21.4	19.0	23.2
$100,000–149,000	29.9	29.8	30.4	29.7	29.7	30.1
≥$150,000	40.6	40.5	29.9	41.5	42.5	39.9
BMI, kg/m2 %
<18.5	1.6	1.5	1.8	1.5	1.7	1.3
18.5–24	50.7	46.8	42.4	48.0	53.6	45.0
25–29	23.5	26.0	28.4	25.2	26.2	25.6
≥30	24.2	25.7	27.4	25.4	18.5	28.1
Race and ethnicity
Asian or Pacific Islander, non-Hispanic	3.3	2.7	2.6	2.7	3.8	2.4
Black, non-Hispanic	1.4	2.0	2.1	1.9	1.6	1.9
Hispanic/Latina	7.3	7.2	5.6	7.4	7.7	7.1
Mixed race/other race	3.1	3.6	5.2	3.4	3.2	3.6
White, non-Hispanic	84.8	83.8	84.0	84.0	82.8	84.5
Endometriosis, %	2.9	2.4	3.6	2.3	3.3	1.9
Fibroids, %	2.6	2.1	1.8	2.3	1.5	2.4
PCOS, %	8.5	6.8	7.2	7.1	8.1	6.7
Diabetes, %	0.6	1.3	1.4	1.1	0.8	1.2
Depression, %	34.9	25.6	41.7	26.3	31.3	26.0
Anxiety, %	38.2	33.2	45.2	33.2	35.3	32.9
Post-traumatic stress disorder	7.1	7.0	11.1	6.7	7.1	6.7
Private health insurance, %	91.1	90.6	87.0	91.0	91.0	91.1
Currently employed, %	89.2	90.7	87.7	90.6	90.6	89.9
Primarily worked shift work, %	12.9	10.8	12.2	11.1	13.2	10.6
Worked at night in the past 4 weeks, %	9.9	10.3	10.8	10.1	9.2	10.6
Averaged <7 hrs sleep/night in the past 4 weeks, %	22.7	16.7	28.9	16.9	20.8	16.3
Married to partner, %	90.3	87.7	87.2	88.3	90.0	88.0
Physical activity-hours/week, %g
<10	12.5	8.0	15.1	8.3	8.2	9.0
10–19	21.0	16.3	20.5	16.8	21.1	15.7
20–39	37.2	36.8	33.1	37.3	38.2	36.1
≥40	29.4	39.0	31.3	37.6	32.5	39.2
PSS-10 score, %
<10	13.8	17.5	9.1	17.5	13.7	18.4
10–19	53.8	60.1	45.4	60.1	55.9	60.3
20–29	30.1	21.3	40.6	21.4	28.6	20.2
≥30	2.3	1.2	5.0	1.0	1.9	1.1
Intercourse frequency, %
<1 time/week	43.8	23.0	46.1	25.4	31.8	24.8
1 time/week	22.6	22.5	20.9	22.7	21.4	23.2
2–3 times/week	29.0	43.6	28.4	41.9	37.6	42.4
≥4 times/week	4.6	10.8	4.6	10.1	9.2	9.7
History of unwanted sexual contacth	48.3	50.2	56.1	49.3	52.2	49.6
Partner showed love and affection in last yearh
Rarely/never	1.5	0.5	1.0	0.8	0.8	0.6
Some of the time	8.5	2.9	10.0	3.5	3.4	4.0
Most of the time	37.5	28.6	39.3	29.5	32.8	29.1
All the time	52.5	67.9	49.7	66.3	63.0	66.4
Could count on partner for emotional supporth
Rarely/never	4.1	0.8	4.4	1.3	1.8	1.3
Some of the time	11.1	5.5	13.0	6.0	7.9	5.8
Most of the time	36.6	31.2	43.9	31.1	34.8	30.4
All the time	48.3	62.6	38.8	61.6	55.5	62.5

Abbreviations: BMI=body mass index, MET=metabolic equivalent, PCOS=polycystic ovarian syndrome, SAB=spontaneous abortion, USD=United States dollars.

^aPercentages standardized based on the sample distribution of age at baseline.

^bDefined as a score ≤19 on a modified version of the 6-item Female Sexual Function Index.²¹

^cDefined as a score ≥20 on the Female Sexual Distress Scale.²³

^dExcludes participants who report no sexual intercourse in the past 4 weeks (N=56) and those who report the presence of an infection causing pain in the past 4 weeks (N=79).

^eIncludes those who report no current job, who have a value of 0.

^fDefined as ever having attempted pregnancy for ≥12 months without becoming pregnant.

^gCalculated using metabolic equivalent of task (MET) hours per week.²⁴

^hCollected on a supplementary survey administered 30 days post enrollment.

We did not see evidence of an association between FSD and TTP when using the previously-established cutpoint for FSD²¹ (fully-adjusted FR 1.01, 95% CI 0.90–1.14). However, we did observe a reduction in fecundability among those in the first (score range 0–20), second (score range 21–22), and third (score range 23–25) quartiles of sexual function scores compared with those in the fourth quartile (highest function, score range 26–30). We found reduced fecundability among those with sexual distress as determined by the published cut point²³ (fully-adjusted FR 0.82, 95% CI 69–0.98) and among those in the fourth (score range 12–48), third (score range 6–11), and second (score range 2–5) quartiles, compared with the first (lowest distress, score range 0–1) (Table 2). Spline results indicated that FRs declined steadily with decreasing scores on the modified FSFI-6, plateauing around 22. There was a steep decrease in fecundability with increasing FSDS (Figure 2). ‘Any pain with intercourse’ was not appreciably associated with reduced fecundability (fully-adjusted FR 1.03, 95% CI 0.93, 1.14) but reporting painful intercourse ‘most times, almost always or always’ was associated with a longer TTP compared with ‘almost never or never’ (fully-adjusted FR 0.81, 9% CI 0.62, 1.06) (Table 3). Accounting for participation bias using IPW did not meaningfully change the results (Tables 2 and 3). Neither restricting the sample to those with ≤3 cycles of conception attempts nor to those without a partner issue meaningfully changed the results (Supplementary Tables 2 & 3) and Supplementary Table 4.

Table 2.

Association between sexual dysfunction and distress in the past 4 weeks and fecundability in PRESTO (N=2,500)

	N	Number of cycles	Number of pregnancies	Crude FR (95% CI)	Age-only adjusted FR (95% CI)	Fully-adjusteda FR (95% CI)	Fully-adjusted with IPW for response (95% CI)
Female sexual dysfunctionb
Yes	502	1893	310	0.96 (0.86, 1.07)	0.97 (0.87, 1.09)	1.01 (0.90, 1.14)	1.00 (0.90, 1.13)
No	1998	7422	1277	Ref	Ref	Ref	Ref
FSFI-621 score, quartilesc
First (lowest function)	649	2488	401	0.87 (0.77, 0.99)	0.87 (0.77, 0.99)	0.89 (0.78, 1.01)	0.90 (0.76, 1.06)
Second	458	1732	279	0.87 (0.76, 1.00)	0.87 (0.76, 1.00)	0.86 (0.75, 0.99)	0.88 (0.75, 1.04)
Third	804	2996	512	0.91 (0.81, 1.02)	0.90 (0.80, 1.01)	0.90 (0.80, 1.01)	0.90 (0.77, 1.04)
Fourth (highest function)	589	2099	395	Ref	Ref	Ref	Ref
Sexual distressd
Yes	219	892	117	0.77 (0.65, 0.92)	0.77 (0.65, 0.92)	0.82 (0.69, 0.98)	0.80 (0.67, 0.945)
No	2281	8423	1470	Ref	Ref	Ref	Ref
Female Sexual Distress Scale23 summed score, quartilese
Fourth (highest distress)	627	2502	369	0.77 (0.68, 0.87)	0.78 (0.69, 0.88)	0.79 (0.69, 0.90)	0.80 (0.68, 0.94)
Third	521	1942	341	0.91 (0.81, 1.03)	0.91 (0.80, 1.03)	0.90 (0.79, 1.03)	0.89 (0.76, 1.05)
Second	644	2455	406	0.86 (0.77, 0.97)	0.85 (0.75, 0.96)	0.83 (0.73, 0.93)	0.75 (0.64, 0.87)
First (lowest distress)	708	2416	471	Ref	Ref	Ref	Ref

Abbreviations: CI, confidence interval; FSFI-6, modified Female Sexual Function Index 6-item, FR, fecundability ratio; IPW, inverse probability weighting; PRESTO, Pregnancy Study Online.

^aAdjusted for endometriosis, polycystic ovarian syndrome, fibroids, diabetes, depression, anxiety, post-traumatic stress disorder, history of any sexually transmitted infection, age, marital status, race/ethnicity, body mass index, education, annual household income, health insurance coverage, employment status, average hours worked per week, rotating shifts, work at night, average alcoholic drinks consumed per week, cigarette smoking status, sleep duration, physical activity, general stress, a history of live birth, history of infertility, history of lifetime unwanted sexual contact, and degree of past-year perceived love and affection, and emtional support, from partner.

^bDefined as a score ≤19 on a modified version of the 6-item Female Sexual Function Index.²¹

^cScore ranges for quartiles are: 0–20 for quartile 1, 21–22 for quartile 2, 23–25 for quartile 3, 26–30 for quartile 4.

^dDefined as a score ≥20 on the Female Sexual Distress Scale.²³

^eScore ranges for quartiles are: 0–1 for quartile 1, 2–5 for quartile 2, 6–11 for quartile 3, and 12–48 for quartile 4.

Figure 2. Adjusted associations between continuous score on the modified FSFI-6 and FSDS and fecundability, fitted by restricted cubic splines, PRESTO, 2021–2024.

Abbreviations: FSDS, Female Sexual Distress Scale; FSFI-6, modified 6-item Female Sexual Function Index; PRESTO, Pregnancy Study Online.

A) Continuous score on the modified FSFI-6.²¹ The reference value was 30 (highest function). Knots are located at the 10^th percentile (17), 50^th percentile (23), and 90^th percentile (27); and B) Continuous score on the FSDS²³. The reference value was 0 (lowest distress). Knots are located at the 25^th percentile (1), 50^th percentile (5), 75^th percentile (12), and 90^th percentile (19). Both models were adjusted for endometriosis, polycystic ovarian syndrome, fibroids, type 2 diabetes, depression, anxiety, post-traumatic stress disorder, history of any sexually transmitted infection, age, marital status, body mass index, race/ethnicity, education, annual household income, health insurance coverage, employment status, average hours worked per week, rotating shifts, work at night, average alcoholic drinks consumed per week, cigarette smoking status, cannabis use, sleep duration, physical activity, general stress, a history of live birth, a history of infertility, a history of unwanted sexual contact, and past-year partner love and support.

Table 3.

Painful intercourse in the past 4 weeks and fecundability in PRESTO (N=2,365)^a

	N	Number of cycles	Number of pregnancies	Crude FR (95% CI)	Age-only adjusted FR (95% CI)	Fully-adjustedb FR (95% CI)	Adjustedc FR without psychosocial covariates (95% CI)	Fully-adjusted FR with IPW for response (95% CI)
Any pain in the past 4 weeksc
Any pain	700	2575	460	1.05 (0.95, 1.16)	1.04 (0.94, 1.15)	1.04 (0.94, 1.15)	1.03 (0.93, 1.14)	1.03 (0.93, 1.13)
Most times, almost always, or always	86	334	48	0.86 (0.66, 1.12)	0.84 (0.65, 1.10)	0.82 (0.63, 1.08)	0.81 (0.62, 1.06)	0.79 (0.61, 1.04)
Sometimes	134	470	88	1.09 (0.89, 1.32)	1.06 (0.87, 1.29)	1.07 (0.88, 1.30)	1.06 (0.87, 1.29)	1.04 (0.86, 1.26)
A few times	480	1771	324	1.08 (0.97, 1.21)	1.07 (0.96, 1.20)	1.07 (0.95, 1.20)	1.06 (0.95, 1.19)	1.07 (0.96, 1.19)
Almost never or never	1665	6258	1051	Ref	Ref	Ref	Ref	Ref

Abbreviation: CI, confidence interval; FR, fecundability ratio; IPW, inverse probability weighting; PRESTO, Pregnancy Study Online

^aExcludes people who reported no sexual intercourse in the past 4 weeks (N=56) and people who reported the presence of an infection causing vaginal pain in the past 4 weeks (N=79).

^bAdjusted for endometriosis, polycystic ovarian syndrome, fibroids, diabetes, depression, anxiety, post-traumatic stress disorder, history of any sexually transmitted infection, age, marital status, race/ethnicity, body mass index, education, annual household income, health insurance coverage, employment status, average hours worked per week, rotating shifts, work at night, average alcoholic drinks consumed per week, cigarette smoking status, cannabis use, sleep duration, physical activity, general stress, a history of live birth, history of infertility, history of lifetime unwanted sexual contact, and degree of past-year perceived love and affection, and emtional support, from partner..

^cAdjusted for endometriosis, polycystic ovarian syndrome, fibroids, diabetes, depression, anxiety, post-traumatic stress disorder, history of any sexually transmitted infection, age, body mass index, race/ethnicity, education, annual household income, health insurance coverage, average alcoholic drinks consumed per week, cigarette smoking status, stress, a history of live birth, and history of infertility.

Distributions of individual domain responses are presented in Supplementary Figure 3. We observed little to no association between reported level of sexual desire, arousal, or satisfaction in the past four weeks and TTP. Lower self-reported orgasm frequency and lubrication were associated with longer TTP (Table 4). The strongest effect estimate was a U-shaped association for orgasm frequency, with those who reported orgasming ‘sometimes’ and ‘never, almost never, or a few times’ having adjusted FRs of 0.74 (95% CI 0.65, 0.85) and 0.93 (95% CI 0.83, 1.03), respectively, compared with those who report orgasming ‘most times, almost always, or always.’

Table 4.

Domain-specific associations between lower sexual function and fecundability in PRESTO (N=2,500)

	N	Number of cycles	Number of pregnancies	Crude FR (95% CI)	Age-only adjusted FR (95% CI)	Fully-adjusteda FR (95% CI)
Sexual desire or interest
None, very low, or low	616	2265	385	1.07 (0.93, 1.21)	1.06 (0.93, 1.21)	1.02 (0.90, 1.17)
Moderate	1283	4747	838	1.10 (0.98, 1.23)	1.09 (0.98, 1.22)	1.04 (0.93, 1.16)
High or very high	601	2303	364	Ref	Ref	Ref
Sexual arousalb
None, very low, or low	330	1279	204	0.92 (0.80, 1.06)	0.92 (0.80, 1.06)	0.93 (0.80, 1.07)
Moderate	1068	3989	678	0.98 (0.89, 1.08)	0.98 (0.89, 1.08)	0.96 (0.87, 1.05)
High or very high	1062	3906	687	Ref	Ref	Ref
Orgasm frequencyb
Never, almost never, or a few times	587	2267	374	0.92 (0.82, 1.02)	0.91 (0.82, 1.01)	0.93 (0.83, 1.03)
Sometimes	393	1567	213	0.76 (0.66, 0.88)	0.75 (0.65, 0.86)	0.74 (0.65, 0.85)
Most times, almost always or always	1480	5340	982	Ref	Ref	Ref
Difficulty with lubricationb
Very or extremely difficult or impossible	113	469	68	0.85 (0.68, 1.07)	0.86 (0.69, 1.07)	0.89 (0.71, 1.12)
Difficult	253	1033	157	0.88 (0.76, 1.02)	0.88 (0.76, 1.03)	0.91 (0.78, 1.06)
Not or slightly difficult	2094	7672	1344	Ref	Ref	Ref
Satisfaction with sex life
Very or moderately dissatisfied	369	1392	217	0.88 (0.77, 1.01)	0.90 (0.79, 1.03)	0.94 (0.82, 1.08)
Neutral	392	1500	240	0.90 (0.79, 1.02)	0.90 (0.80, 1.03)	0.93 (0.82, 1.06)
Moderately or very satisfied	1739	6423	1130	Ref	Ref	Ref

Abbreviation: CI, confidence interval; FR, fecundability ratio; IPW, inverse probability weighting; PRESTO, Pregnancy Study Online

^aAdjusted for endometriosis, polycystic ovarian syndrome, fibroids, diabetes, depression, anxiety, post-traumatic stress disorder, history of any sexually transmitted infection, age, marital status, race/ethnicity, body mass index, education, annual household income, health insurance coverage, employment status, average hours worked per week, rotating shifts, work at night, average alcoholic drinks consumed per week, cigarette smoking status, cannabis use, sleep duration, physical activity, general stress, a history of live birth, history of infertility, history of lifetime unwanted sexual contact, and degree of past-year perceived love and affection, and emotional support, from partner.

^bExcludes 40 people who reported no sexual activity in the past 4 weeks.

Comment

Principal findings

In this North American preconception cohort study, we did not find an association between FSD and TTP using a previously-validated cut point.²¹ However, we did find an association between quartiles representing lower sexual function and delayed conception. We also found an association of sexual distress and frequent painful intercourse with delayed conception. Exploratory analyses suggested some evidence of an association of lower levels of lubrication and orgasm frequency and delayed conception.

Results in the context of what is known

Our results are consistent with another study that evaluated preconception female sexual function and TTP.¹⁷ That study reported a FR of 0.73 for participants with lower sexual function compared with those having higher function. They defined ‘lower sexual function’ as the median value of their sample; our quartile-based analysis suggested that participants in the highest quartile of sexual function scores had the shortest TTP.

Clinical implications

We report an association between sexual distress and prolonged TTP. Those reporting sexual distress also reported less frequent intercourse, so intercourse frequency may play a role in this association. Another potential mechanistic pathway is stress. Prior research has reported associations between high stress levels and longer TTP.^28,43 Our observed association persisted despite adjustment for general stress, as measured by the PSS-10.²⁵ Conception attempts may exacerbate distressing sexual health issues, causing a stress response that affects reproductive function.⁴⁵ It is also possible that low intercourse frequency causes sexual distress and is not a mediator. We cannot determine the temporality of intercourse frequency and distress in our data.

We found that frequent painful intercourse was associated with longer TTP but occasional pain was not. Inadequate lubrication is associated with painful sex;⁴⁶ therefore, participants who occasionally experience painful sex may preferentially time intercourse. Because cervical mucus and vaginal lubrication are increased during the fertile window^47–50 and hormonal fluctuations around ovulation are associated with increased sexual desire,⁵¹ pain may decrease as conception chances increase. Relatedly, it is possible that frequent pain interferes with the frequency and timing of intercourse; the small sample size precluded a formal mediation analysis. Painful intercourse may be caused by upstream factors (e.g., hormones) that also influence TTP.⁵² Providers may wish to ask patients about painful intercourse during preconception counseling, as personal lubricant use may ameliorate pain⁵³ and is not associated with TTP.⁵⁴

Exploratory analyses suggested that the association of sexual function and TTP differed by domain. Three domains (desire, satisfaction, and arousal) had little or no relationship to TTP, while lower lubrication and orgasm frequency had an association with longer TTP. Physiologic sexual function is regulated by hormones that also play a role in reproduction (i.e., estrogen) and accompanied by increased blood flow to vulvar tissues, which cause lubrication.⁵⁵ Thus, it is possible that hormonal imbalances or vascular issues that impair sexual function also play a role in conception. Additionally, there is a wealth of literature on the evolutionary origins of the human female orgasm, some of which hypothesizes that it is an adaptive mechanism to aid conception,^56,57 though to our knowledge this is the first study to directly evaluate orgasm in relation to TTP.

Research implications

Our study provides evidence that preconception sexual function may play a role in TTP, which warrants further investigation. Our research suggests potential limitations of the FSFI-6 in etiologic research. Use of the full 19-item Female Sexual Function Index²² provides a more detailed assessment of sexual function and may offer researchers more comprehensive insight. Validated scales of domain-specific sexual function may also be beneficial for future research.

Strengths and limitations

Strengths of our study include the preconception assessment of sexual function in a prospective cohort study and the use of multiple validated instruments to measure female sexual function and distress. Limitations include the use of a different lubrication question than the original FSFI-6²¹ to increase specificity. Though the responses to both questions were highly correlated, direct comparisons with other studies are more challenging. In addition, the FSFI-6 was designed for clinical assessment, not etiologic research.²¹ Indeed, our findings suggest that important domain-specific information may be lost when pooling responses into a single measure. Our domain-specific findings were exploratory because domain-specific questions have not been validated independently. Our sample was primarily non-Hispanic White with high levels of education and income, and were a self-selected population of pregnancy planners, which may influence the distribution of potential confounders (i.e., depression or anxiety) and overall generalizability. Our results are vulnerable to selection bias due to left truncation.⁴² Though our sensitivity analysis with more restrictive criteria for inclusion (i.e., ≤3 cycles of attempts) did not substantially alter our findings, left truncation bias remains a potential limitation. The small sample size in some exploratory analyses limited the precision of the estimates. Finally, not every participant completed the SHQ. IPW suggested little influence of participation bias on our results, but our model may not have included all relevant factors.

Conclusions

Our findings indicate an association of higher levels of sexual dysfunction and distress and frequent painful intercourse with delayed conception. Exploratory analyses suggested associations between more difficulty of lubrication, and lower frequency of orgasm with longer TTP. Because individuals rarely discuss sexual health with healthcare providers,^18,58–63 sexual function issues may be an underappreciated contributor to prolonged conception attempts. Clinicians should consider discussing sexual function in preconception counseling visits.

AJOG at a Glance:

A. Why was this study conducted?

Although sexual intercourse is important for many couples attempting spontaneous conception, little research has evaluated the association between sexual function and time to pregnancy.

B. What are the key findings?

We found an association of lower female sexual function, higher levels of sexual distress, and frequent painful intercourse with prolonged time to pregnancy.

C. What does this study add to what is already known?

This study demonstrates an association between elements of sexual function, including associated distress and frequent painful intercourse, and prolonged time-to-pregnancy. Assessment and discussion of sexual functioning in preconception counseling may identify issues that affect time-to-pregnancy.