Prepregnancy plant-based diets and risk of hypertensive disorders of pregnancy

BACKGROUND

Plant-based diets have been associated with a lower risk of cardiovascular disease in nonpregnant adults, but specific evidence for their effects on risk of hypertensive disorders of pregnancy is scarce.

OBJECTIVE

This study aimed to evaluate the prospective association between adherence to plant-based diets before pregnancy and the risk for hypertensive disorders of pregnancy. We hypothesized that women with higher adherence to plant-based diets would have a lower risk for hypertensive disorders of pregnancy.

STUDY DESIGN

We followed 11,459 parous women (16,780 singleton pregnancies) without chronic diseases, a history of preeclampsia, and cancers who participated in the Nurses' Health Study II (1991-2009), which was a prospective cohort study. Diet was assessed every 4 years using a validated food frequency questionnaire from which we calculated the plant-based diet index (higher score indicates higher adherence) to evaluate the health associations of plant-based diets among participants while accounting for the quality of plant-based foods. Participants self-reported hypertensive disorders of pregnancy, including preeclampsia and gestational hypertension. We estimated the relative risk of hypertensive disorders of pregnancy in relation to plant-based diet index adherence in quintiles using generalized estimating equations log-binomial regression while adjusting for potential confounders and accounting for repeated pregnancies for the same woman.

RESULTS

The mean (standard deviation) age at first in-study pregnancy was 35 (4) years. A total of 1033 cases of hypertensive disorders of pregnancy, including 482 cases of preeclampsia (2.9%) and 551 cases of gestational hypertension (3.3%) were reported. Women in the highest quintile of plant-based diet index were significantly associated with a lower risk for hypertensive disorders of pregnancy than women in the lowest quintile (relative risk, 0.76; 95% confidence interval, 0.62-0.93). There was an inverse dose-response relationship between plant-based diet index and risk for hypertensive disorders of pregnancy. The multivariable-adjusted relative risk (95% confidence interval) of hypertensive disorders of pregnancy for women in increasing quintiles of plant-based diet index were 1 (ref), 0.93 (0.78-1.12), 0.86 (0.72-1.03), 0.84 (0.69-1.03), and 0.76 (0.62-0.93) with a significant linear trend across quintiles (P trend=.005). This association was slightly stronger for gestational hypertension (relative risk, 0.77; 95% confidence interval, 0.60-0.99) than for preeclampsia (relative risk, 0.80; 95% confidence interval, 0.61-1.04). Mediation analysis suggested that body mass index evaluation for dietary assessment and pregnancy explained 39% (95% confidence interval, 15%-70%]) of the relation between plant-based diet index and hypertensive disorders of pregnancy and 48% (95% confidence interval, 12%-86%]) of the relation between plant-based diet index and gestational hypertension.

CONCLUSION

Higher adherence to plant-based diets was associated with a lower risk of developing hypertensive disorders of pregnancy. Much of the benefit seems to be related to improved weight control.

Prepregnancy Healthy Lifestyle and Adverse Pregnancy Outcomes

OBJECTIVE

To investigate the association of healthy lifestyle factors before pregnancy (body mass index [BMI] 18.5-24.9, nonsmoking, 150 min/wk or more of moderate-to-vigorous physical activity, healthy eating [top 40% of Dietary Approaches to Stop Hypertension score], no or low-to-moderate alcohol intake [less than 15 g/d], and use of multivitamins) with risk of adverse pregnancy outcomes.

METHODS

We conducted a secondary analysis of prospectively collected data for women without chronic diseases who are participating in an ongoing cohort in the United States (the NHSII [Nurses' Health Study II]). Healthy lifestyle factors preceding pregnancy were prospectively assessed every 2-4 years from 1991 to 2009 with validated measures. Reproductive history was self-reported in 2001 and 2009. A composite outcome of adverse pregnancy outcomes that included miscarriage, ectopic pregnancy, gestational diabetes, gestational hypertension, preeclampsia, preterm birth, stillbirth, or low birth weight was assessed.

RESULTS

Overall, 15,509 women with 27,135 pregnancies were included. The mean maternal age was 35.1±4.2 years. Approximately one in three pregnancies (n=9,702, 35.8%) was complicated by one or more adverse pregnancy outcomes. The combination of six low-risk factors was inversely associated with risk of adverse pregnancy outcomes in a dose-dependent manner ( P for trend <.001). Compared with women who had zero or one healthy lifestyle factor, those with six had a 37% lower risk of adverse pregnancy outcomes (relative risk 0.63, 95% CI 0.55-0.72), driven primarily by lower risks of gestational diabetes, gestational hypertension, and low birth weight. All prepregnancy healthy lifestyle factors, except avoiding harmful alcohol consumption and regular physical activity, were independently associated with lower risk of adverse pregnancy outcomes after mutual adjustment for each other. Healthy BMI, high-quality diet, and multivitamin supplementation showed the strongest inverse associations with adverse pregnancy outcomes. If the observed relationships were causal, 19% of adverse pregnancy outcomes could have been prevented by the adoption of all six healthy lifestyle factors (population attributable risk 19%, 95% CI 13-26%).

CONCLUSION

Prepregnancy healthy lifestyle is associated with a substantially lower risk of adverse pregnancy outcomes and could be an effective intervention for the prevention of adverse pregnancy outcomes.

Association of Gestational Diabetes With Subsequent Long-Term Risk of Mortality

Importance

Gestational diabetes has been associated with numerous chronic diseases. However, few studies have examined the association of gestational diabetes with long-term mortality risk.

Objective

To investigate the associations between gestational diabetes and long-term risks of total and cause-specific mortality.

Design, Setting, and Participants

This cohort study analyzed participants of the Nurses' Health Study II who were followed for 30 years (1989-2019). Participants included US female nurses aged 25 to 42 years who reported at least 1 pregnancy (≥6 months) at 18 years or older across their reproductive life span. Data were analyzed from May 1, 2022, to May 25, 2023.

Exposure

Gestational diabetes across the reproductive life span.

Main Outcomes and Measures

Hazard ratios (HRs with 95% CIs) for total and cause-specific mortality were estimated by Cox proportional hazards regression models.

Results

A total of 91 426 parous participants were included, with a mean (SD) age of 34.9 (4.7) years and a body mass index of 24.1 (4.7) at baseline. During a follow-up period of 2 609 753 person-years, 3937 deaths were documented, including 255 deaths from cardiovascular disease and 1397 from cancer. Participants with a history of gestational diabetes had a higher crude mortality rate than those without a history of gestational diabetes (1.74 vs 1.49 per 1000 person-years; absolute difference = 0.25 per 1000 person-years). The corresponding HR for total mortality was 1.28 (95% CI, 1.13-1.44), which did not materially change after additional adjustment for potential confounders and lifestyle factors during the reproductive life span (HR, 1.25; 95% CI, 1.11-1.41). The association persisted regardless of the subsequent development of type 2 diabetes and was more robust among participants who adopted less healthy lifestyles; experienced gestational diabetes in 2 or more pregnancies (HR, 1.48; 95% CI, 0.99-2.19); had gestational diabetes both in the initial and subsequent pregnancies (HR, 1.71; 95% CI, 1.11-2.63); and concurrently reported hypertensive disorders in pregnancy (HR, 1.80; 95% CI, 1.21-2.67), preterm birth (HR, 2.46; 95% CI, 1.66-3.64), or low birth weight (HR, 2.11; 95% CI, 1.21-3.68). Cause-specific mortality analyses revealed that gestational diabetes was directly associated with the risk of mortality due to cardiovascular disease (HR, 1.59; 95% CI, 1.03-2.47). Additionally, gestational diabetes was inversely associated with cancer mortality (HR, 0.76; 95% CI, 0.59-0.98); however, it was only evident among participants who later developed type 2 diabetes.

Conclusions and Relevance

Results of this cohort study suggest that participants who reported a history of gestational diabetes exhibited a small but elevated risk of subsequent mortality over 30 years. The findings emphasize the importance of considering gestational diabetes as a critical factor in later-life mortality risk.

Predictors of Fertility-Awareness-Based Method Use Among Women Trying to Conceive and Women Contemplating Pregnancy

BACKGROUND

Fertility-awareness-based methods have been linked to shorter time to conception; however, little is known about the predictors of fertility-awareness-based method use among women who are currently or will soon be trying to conceive.

OBJECTIVES

The aim of this study was to identify predictors of fertility-awareness-based methods use among women trying to conceive or contemplating pregnancy within the next year.

METHODS

Women participating in the Nurses' Health Study 3 were asked if they were trying to become pregnant or contemplating pregnancy and whether they are using fertility-awareness-based methods. Multivariable negative binomial regression was used to identify predictors for a number of fertility-awareness-based methods used.

RESULTS

Among the 23,418 women asked about pregnancy intention since 2015, 955 were trying to conceive, and 2,282 were contemplating pregnancy within the next year. The three most used fertility-awareness-based methods among women trying to conceive were menstrual cycle tracking, ovulation prediction kits, and cervical mucus monitoring. Among women contemplating pregnancy, the three most commonly used methods were menstrual cycle tracking, cervical mucus monitoring, and basal body temperature monitoring. The ongoing duration of pregnancy attempts and gravidity were associated with the number of methods used among women actively trying to conceive. When compared with women who were trying for 2 months or less, the number of methods was 29% higher when trying for 3-5 months, 45% higher when trying for 6-12 months, and 38% higher when trying for more than 1 year. Compared with nulligravid women, the number of methods was lower for women with a history of two or more pregnancies. Among women contemplating pregnancy, those who were married or in a domestic partnership used more fertility-awareness-based methods than unpartnered women. No other significant predictors of fertility-awareness-based method use were identified.

DISCUSSION

Duration of ongoing pregnancy attempt and gravidity were the only significant predictors for the number of fertility-awareness-based methods used among women actively trying to conceive, whereas partnership was the only significant predictor of the number of fertility-awareness-based methods among women contemplating pregnancy.

Women's Adherence to Healthy Dietary Patterns and Outcomes of Infertility Treatment

Importance

Increasing evidence suggests that specific foods and nutrients may improve infertility treatment outcomes in women. However, less is known about the role of dietary patterns.

Objective

To investigate whether women's adherence to a priori-defined dietary patterns promoted for the prevention of chronic conditions is associated with outcomes of infertility treatment.

Design, Setting, and Participants

This prospective cohort study was conducted at a fertility center at an academic medical center in Boston, Massachusetts. Women undergoing infertility treatment cycles, including intrauterine insemination cycles and in vitro fertilization with or without intracytoplasmic sperm injection were included. Data were collected from January 2007 to October 2019, and data were analyzed from February to December 2022.

Exposures

Women's pretreatment diet was assessed with a validated food frequency questionnaire from which 8 a priori-defined scores were calculated (higher score indicates greater adherence): (1) Trichopoulou Mediterranean diet, (2) alternate Mediterranean diet, (3) Panagiotakos Mediterranean diet, (4) Healthy Eating Index, (5) Alternate Healthy Eating Index, (6) American Heart Association (AHA) index, (7) Dietary Approaches to Stop Hypertension index, and (8) plant-based diet.

Main Outcomes and Measures

The adjusted probability of clinically relevant outcomes (live birth as a primary outcome and clinical pregnancy and pregnancy loss as secondary outcomes) was evaluated across quartiles of adherence to each dietary pattern using multivariable generalized linear mixed models to account for repeated cycles.

Results

This analysis included 612 women with a median (IQR) age of 35.0 (32.0-38.0) years. There was no association between women's adherence to the 8 a priori dietary patterns and probability of clinical pregnancy or live birth following in vitro fertilization or intrauterine insemination. However, an inverse association was found between adherence to AHA dietary pattern and risks of total and clinical pregnancy loss. Among women who became pregnant during the course of infertility treatment, the adjusted probabilities of pregnancy loss in the lowest and highest quartile of the AHA dietary pattern were 0.41 (95% CI, 0.33-0.50) and 0.28 (95% CI, 0.21-0.36), respectively (P for trend = .02). The corresponding adjusted probabilities of clinical pregnancy loss were 0.30 (95% CI, 0.22-0.39) and 0.15 (95% CI, 0.10-0.23) (P for trend = .007). A similar pattern was observed for all other dietary patterns, with the exception of the plant-based diet pattern.

Conclusions and Relevance

Findings of this cohort study suggest that preconception adherence to the AHA diet may be associated with a lower likelihood of pregnancy loss during the course of infertility treatment.

Iron intake in relation to ovarian reserve among women seeking infertility treatment

STUDY QUESTION

Is there an association between iron intake and ovarian reserve among women seeking fertility care?

SUMMARY ANSWER

Supplemental iron intake above 45 mg/day is associated with lower ovarian reserve among women seeking fertility care.

WHAT IS KNOWN ALREADY

Although the literature regarding iron intake in relation to ovarian reserve is scant and inconsistent, some evidence suggests that iron may have gonadotoxic effects.

STUDY DESIGN, SIZE, DURATION

This observational study included 582 female participants attending the Massachusetts General Hospital Fertility Center (2007-2019) enrolled in the Environment and Reproductive Health (EARTH) Study.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Iron intake was estimated using a validated food frequency questionnaire. Markers of ovarian reserve included antral follicle count (AFC) (assessed via transvaginal ultrasound) and Day 3 FSH, both obtained during the course of an infertility evaluation.

MAIN RESULTS AND THE ROLE OF CHANCE

Participants had a median age of 35 years and median total iron intake of 29 mg/day. Total iron intake was inversely related to AFC and this association was driven by intake of supplemental iron. Compared to women with a supplemental iron intake of ≤20 mg/day, women consuming 45-64 mg/day of supplemental iron had a 17% (-35%, 0.3%) lower AFC and women consuming ≥65 mg/day of supplemental iron had a 32% (-54%, -11%) lower AFC after adjusting for potential confounders (P, linear trend = 0.003). Similarly, in a multivariable-adjusted analysis, Day 3 FSH levels were 0.9 (0.5, 1.3) IU/ml higher among women with a supplemental iron intake of ≥65 mg/day when compared to women with a supplemental iron intake of ≤20 mg/day (P, linear trend = 0.02).

LIMITATIONS, REASONS FOR CAUTION

Iron intake was estimated using a method that relies on self-report and we had no biomarkers of iron status in our participants; only 36 women consumed ≥45 mg/day of supplemental iron.

WIDER IMPLICATIONS OF THE FINDINGS

Since all study participants were seeking fertility treatment, our findings may not apply to women in the general population. Although our findings are consistent with studies of women with iron overload, given the paucity of literature on this topic, it is essential that this question is revisited in studies designed to better understand the dose-response relation of this association across the entire distribution of ovarian reserve and the risk-benefit balance of pre-conceptional iron supplementation given its many positive effects on pregnancy outcomes.

STUDY FUNDING/COMPETING INTEREST(S)

The project was funded by Grants R01ES022955, R01ES033651, R01ES009718, P30ES000002, and P30DK046200 from the National Institutes of Health. N.J.-C. was supported by a Fulbright Scholarship. N.J.-C., M.M., L.M.-A., E.O.-P., S.W., I.S., and J.E.C. declare no conflict of interest related to the work in the manuscript. R.H. has received grants from the National Institute of Environmental Health Sciences.

TRIAL REGISTRATION NUMBER

N/A.

Pregnancy Intention, Changes in Pregnancy Intention, and Pregnancy Incidence Among Female Nurses in North America

Importance

Pregnancy intention assessment is a key element of preconception and contraceptive care. The association between a single screening question and the incidence of pregnancy is unknown.

Objective

To prospectively evaluate the dynamics of pregnancy intention and pregnancy incidence.

Design, Setting, and Participants

This prospective cohort study (the Nurses' Health Study 3) was conducted from June 1, 2010, to April 1, 2022, in 18 376 premenopausal, nonpregnant female nurses aged 19 to 44 years.

Main Outcomes and Measures

Pregnancy intention and pregnancy status were assessed at baseline and approximately every 3 to 6 months thereafter. Cox proportional hazards regression models were used to estimate the association between pregnancy intention and pregnancy incidence.

Results

A total of 18 376 premenopausal, nonpregnant women (mean [SD] age, 32.4 [6.5] years) participated in the study. At baseline, 1008 women (5.5%) were trying to conceive, 2452 (13.3%) were contemplating pregnancy within 1 year, and the remaining 14 916 (81.2%) were neither trying to conceive nor thought they would be pregnant within 1 year. A total of 1314 pregnancies were documented within 12 months of pregnancy intention assessment. The cumulative incidence of pregnancy was 38.8% in women actively trying to conceive (median [IQR] time to pregnancy, 3.3 [1.5-6.7] months), 27.6% in women contemplating pregnancy (median [IQR] time to pregnancy, 6.7 [4.2-9.3] months), and 1.7% in women neither trying to conceive nor contemplating pregnancy (median [IQR] time to pregnancy, 7.8 [5.2-10.5] months) among those who became pregnant. Women who were actively trying to conceive were 23.1 times (95% CI, 19.5-27.4 times) and women who were contemplating pregnancy were 13.0 times (95% CI, 11.1-15.2 times) more likely to conceive within 12 months than women who were neither attempting nor contemplating pregnancy. Among women contemplating pregnancy at baseline who did not get pregnant during follow up, 18.8% were actively trying and 27.6% were not trying by 12 months. Conversely, only 4.9% of women neither trying to conceive nor contemplating pregnancy within 1 year at baseline changed pregnancy intention during follow up.

Conclusions and Relevance

In this cohort study of reproductive-aged nurses in North America, pregnancy intention was highly fluid among women who were contemplating pregnancy but relatively stable among women trying to conceive and women who were neither trying to conceive nor contemplating pregnancy. Pregnancy intention was strongly associated with pregnancy incidence, but the median time to pregnancy points to a relatively short time window to initiate preconception care.

Intake of soy products and soy isoflavones in relation to ovarian reserve

BACKGROUND

Previous studies suggest on the relation between soy intake and human fertility are inconsistent. Some clinical studies suggest that soy and phytoestrogens may not be deleterious to reproduction and may even be beneficial in couples undergoing infertility treatment. However, no studies have evaluated the relation between soy or isoflavone intake with markers of ovarian reserve other than follicle stimulating hormone (FSH).

OBJECTIVE

To investigate the association between intakes of soy food and isoflavone with ovarian reserve.

DESIGN

Cross-sectional study SETTING: Patients presenting to an academic fertility center between 2007 and 2019 were invited to participate in the Environment and Reproductive Health (EARTH) Study. Patients, Exposure(s): 667 participants reported their soy food intake and had an antral follicle count (AFC) assessment. Intake of 15 soy-based foods during the previous three months was obtained at baseline and intake of isoflavone was estimated from these reports. Participants were divided into five groups based on soy food and isoflavone intake using those who did not consume soy as the reference group.

MAIN OUTCOME MEASURE(S)

Ovarian reserve was assessed using AFC as the primary outcome measure, with AMH and FSH as secondary outcome measures. AFC was measured on the third day of the menstrual cycle. FSH and anti-Mullerian hormone (AMH) were measured in blood samples obtained on the third day and the follicular phase of the menstrual cycle. To evaluate the association between soy intakes and ovarian reserve, we used Poisson regression models for AFC and quantile regression models for AMH and day 3 FSH adjusting for confounders.

RESULTS

Participants had a median age of 35.0 years. The median intake of soy was 0.09 servings/day and isoflavones was 1.78 mg/day. AFC, AMH and FSH were unrelated to soy intake in crude analyses. We found no association between soy food intake with AFC or day 3 FSH in multivariable models. However, participants in the highest category of soy foods intake had significantly lower AMH levels (-1.16, 95% CI: -1.92, -0.41). Soy intake had no association with AFC, AMH, or FSH in sensitivity analyses that included using different cutoff points of soy intake, excluding participants in the highest 2.5 percentile of intake, and additional statistical adjustment for dietary patterns.

CONCLUSION

The results of this study are not consistent with a strong positive or inverse association of soy or isoflavone intakes within the observed range of intake, which substantially overlaps with that in the general population of the USA, and ovarian reserve among individuals presenting to fertility centers.

Abstract 15: Pre-Pregnancy Healthy Lifestyle is Associated With Lower Risk of Adverse Pregnancy Outcomes: A Prospective Cohort Study

Introduction: Adverse pregnancy outcomes (APOs) have been linked with maternal mortality, higher risk of metabolic and cardiovascular diseases, and adverse neonatal outcomes. The World Health Organization recommends the adoption of a healthy lifestyle (maintaining a normal BMI, not smoking, regular exercise, healthy diet, avoiding harmful alcohol intake, and multivitamin supplementation) before conception to improve pregnancy health. However, the combined effect of these lifestyle factors on reducing APOs is unknown.

Hypothesis: Adherence to healthy lifestyle prior to pregnancy may be associated with a lower risk of subsequent development of APOs.

Methods: We followed 15,509 women without chronic diseases (27,135 pregnancies) and participating in an ongoing cohort in the United States, the Nurses’ Health Study II. Healthy lifestyle factors preceding pregnancy were prospectively assessed every 2 to 4 years from 1991 to 2009, using validated measures. Reproductive history was self-reported in 2001 and 2009. A composite outcome of APOs included miscarriage, ectopic pregnancy, gestational diabetes, gestational hypertension, preeclampsia, preterm birth, stillbirth, and low birth weight (<5.5 lbs). We estimated the relative risks (RRs) of APOs according to the number of healthy lifestyle factors (0-6), using Poisson regression models with generalized estimating equations, specifying an exchangeable correlation structure, adjusting for maternal age, race/ethnicity, year of birth, history of infertility, parity, and interpregnancy interval.

Results: The mean (SD) maternal age was 35.1 (4.2) years. Nearly one in three pregnancies (N=9,702, 35.8%) were complicated with an APO. All healthy lifestyle factors, except alcohol consumption, were independently associated with APOs after mutual adjustment for each other. The combination of 6 low-risk factors (BMI=18.5-24.9 kg/m 2 , non-smoking, ≥150 minutes/week of moderate to vigorous physical activity, healthy eating (top 40% of Dietary Approaches to Stop Hypertension score), low-to-moderate alcohol intake (<15 g/day), and use of multivitamin) was inversely associated with risk of APOs, in a dose-dependent manner ( P trend<0.001). Compared to women who had 0 or 1 healthy lifestyle factors, those with 6 had a 45% lower risk of APOs (RR=0.55, 95% CI=0.44-0.68). The associations were stronger among women who were <35 years or had BMI <25 kg/m 2 but did not differ by parity. If the relationships were causal, 10% of APOs in the study population could have been prevented by the adoption of all 6 healthy lifestyle factors (population attributable risk=10%, 95% CI=6%-14%).

Conclusions: Our findings suggest that pre-conception healthy lifestyle is associated with a substantially lower risk of APOs and could be an effective intervention for the prevention of APOs and their downstream long-term maternal and offspring health consequences.

Pre-pregnancy fat intake in relation to hypertensive disorders of pregnancy

BACKGROUND

Many studies have linked intakes of fat and of specific fatty acids during pregnancy with preeclampsia; however, information on the association of intake before pregnancy with hypertensive disorders of pregnancy (HDP) is scant.

OBJECTIVES

We evaluated the associations of intakes of major and specific types of fat before pregnancy with the risks of HDP, including preeclampsia and gestational hypertension (GHTN).

METHODS

We followed 11,535 women without chronic disease participating in the Nurses' Health Study II from 1991 and 2009. Pre-pregnancy dietary fat was assessed by an FFQ. Intakes of total fat, saturated fat, trans fatty acid (TFA), MUFAs, PUFAs, and fat subtypes (omega-3 and omega-6) were categorized into quintiles of intake. HDP were self-reported. The RRs (95% CIs) of HDP were estimated by log-binomial generalized estimating equation regression models, with an exchangeable correlation matrix to account for repeated pregnancies while adjusting for potential confounders.

RESULTS

During 19 years of follow-up, there were 495 cases of preeclampsia (2.9%) and 561 (3.3%) cases of GHTN in 16,892 singleton pregnancies. The mean age at pregnancy was 34.6 years (SD, 3.9 years). Among major fat types, only pre-pregnancy TFA was related to a higher risk of HDP (RR, 1.32; 95% CI: 1.05-1.66), and only for preeclampsia (RR, 1.50; 95% CI: 1.07-2.10) but not for GHTN (RR, 1.21; 95% CI: 0.87-1.70). Among specific types of PUFAs, intake of arachidonic acid was positively related with GHTN (RR, 1.43; 95% CI: 1.00-2.04) but not preeclampsia (RR, 1.08; 95% CI: 0.75-1.57). In analyses restricted to pregnancies 1 year after the diet assessment, women with the highest intake of long-chain omega-3 fatty acids had a 31% lower risk of HDP (95% CI: 3%-51%), which was driven by preeclampsia (RR, 0.55; 95% CI: 0.33-0.92).

CONCLUSIONS

Pre-pregnancy intakes of total fat, saturated fat, and MUFA were unrelated to HDP, whereas TFA was positively related to HDP. These findings highlight the importance of ongoing efforts to eliminate TFA from the global food supply.

Importance of human papillomavirus vaccination leaflets focusing on the safety profile targeted pediatricians in Japan

OBJECTIVES

To investigate the association between providing leaflets to support pediatricians in explaining the safety of the human papillomavirus (HPV) vaccine and mother's decision to vaccinate their daughters in Japan.

METHODS

In this cross-sectional study, we conducted a survey of mothers to evaluate the effect of leaflets that were created to support pediatricians in explaining the safety profile of the HPV vaccine. Mothers who provided consent for vaccination before receiving an explanation were excluded from the study. The primary outcome was the mother's decision to vaccinatetheir daughters with the HPV vaccine after receiving an explanation from pediatricians using our leaflets.

RESULTS

Among 161 eligible mothers, 101 decided on HPV vaccination (decided group) and 60 did not (decided against group). There was no difference in the maternal background between the 2 groups. The decided group had a significantly more positive impression of the leaflets than the undecided group. In multivariable logistic regression analysis, a detailed explanation for possible adverse events and specific solutions to them was associated with the mother's decision to have their daughters vaccinated (odds ratio 2.35, 95% confidence interval 1.02-5.44), but not the pathology of cervical cancer and the HPV vaccination process.

CONCLUSION

Leaflets emphasizing an explanation of adverse events may contribute to mothers' decision making for HPV vaccination.

P-647 Intake of soy foods and soy isoflavones in relation to ovarian reserve among women presenting to a fertility center

Study question

Are soy food and isoflavone intakes associated with ovarian reserve as measured by antral follicle count (AFC)?

Summary answer

Within the observed range of intake, soy food or isoflavone consumptions are not associated with AFC.

What is known already

Phytoestrogens are structurally similar to 17β-estradiol, and bind to ER-α and ER-β in vitro resulting in weak estrogenic activity. Previous work in ruminants, felines and rodents has shown that exposure to phytoestrogens can have major adverse impacts on reproduction. However, findings of studies in humans suggest that soy foods and soy phytoestrogens may not have major deleterious impacts on reproductive hormone levels or reproductive outcomes, and could even be beneficial in couples undergoing infertility treatment.

Study design, size, duration

Women presenting to a large academic fertility center between April 2007 and December 2019 were invited to participate in the Environment and Reproductive Health (EARTH) Study, a prospective cohort study. Intake of 15 soy-based foods during the previous three months was obtained at baseline and intake of soy phytoestrogens was estimated from these reports. AFC was assessed with transvaginal ultrasound performed as part of diagnostic evaluation for infertility.

Participants/materials, setting, methods

We included 667 women who reported their soy food intake and had an AFC assessment. Women were divided in groups of increasing soy food and soy isoflavone intake with women who reported not consuming soy-based foods serving as the reference group. We evaluated the association of soy foods and soy isoflavones intake with AFC using Poisson regression models adjusting for confounders. Analyses were also stratified by age, BMI, and smoking status.

Main results and the role of chance

Women had median baseline age of 35.0 years and BMI of 23.4 kg/m2. Mean (range) intake of soy foods was 0.1 (0-7.4) servings/day, and mean (range) intake of isoflavones was 6 (0-166) mg/day, which is comparable to that of women in the general population of the USA. Intakes of soy foods or isoflavones were not related to AFC. The median (IQR) AFC for women who did not consume soy foods and women in the highest category of soy intake (&gt;0.45 servings/day, median 0.88 servings/day) were 12 (9, 18) and 13 (9, 19). After adjustment for potential confounders, the mean difference in AFC between women in the highest category of soy intake and women who did not consume soy was -0.5% (-6.6%, 6.1%). Soy food intake remained unrelated to AFC when intake was categorized using different cutoff values when intake was modeled as a continuous variable when departures from a linear association were considered, and when we excluded from analysis 76 women whose AFC ultrasound scan was performed before they completed the diet assessment. Soy intake was also unrelated to AFC within categories of age, BMI and smoking status. Findings for soy isoflavones mirrored those for soy-food intake.

Limitations, reasons for caution

Self-reported soy intake may have resulted in measurement error leading to attenuation of observed relations towards the null. Also, all participants were women presenting to a fertility center and therefore, findings may not be generalizable to women in the general population.

Wider implications of the findings

Our findings suggest soy food and isoflavone intakes within the ranges observed among women in the general population of the USA is unlikely to influence ovarian reserve in any meaningful way.

Trial registration number

Not applicable

Paternal adherence to healthy dietary patterns in relation to sperm parameters and outcomes of assisted reproductive technologies

OBJECTIVE

To investigate whether men's adherence to dietary patterns promoted for the prevention of cardiovascular disease is associated with semen parameters and couples' assisted reproductive technology (ART) outcomes.

DESIGN

Prospective cohort study.

SETTING

Fertility center at an academic medical center.

PATIENT(S)

A total of 245 men and their female partners who underwent 438 ART cycles between 2007 and 2020.

INTERVENTION(S)

Male pretreatment dietary intake was assessed with a 131-item food frequency questionnaire from which we calculated eight a priori defined scores: Trichopoulou Mediterranean, Alternate Mediterranean, Panagiotakos Mediterranean, Healthy Eating Index, Alternative Healthy Eating Index, American Heart Association, Dietary Approaches to Stop Hypertension, and Plant-based.

MAIN OUTCOME MEASURE(S)

The primary outcome was live births per treatment cycle. The secondary outcomes were fertilization, implantation, and clinical pregnancy and seminogram parameters.

RESULT(S)

There was an inverse association between greater adherence by men to the Panagiotakos Mediterranean diet and the American Heart Association dietary pattern and lower fertilization rate. However, there were no significant associations between men's adherence to any of the analyzed dietary patterns and the probabilities of implantation, clinical pregnancy, or live birth in multivariable-adjusted models. No significant differences in any of the semen parameters were found between participants of the lowest quartile and those of the highest quartile of the eight dietary patterns.

CONCLUSION(S)

These findings suggest that men's adherence to several a priori defined dietary scores with documented cardiovascular benefits is not related to major outcomes of infertility treatment with ART or semen quality.

A dietary score representing the overall relation of men's diet with semen quality in relation to outcomes of infertility treatment with assisted reproduction

Objective

To examine the impact of men's diet on outcomes of infertility treatment with assisted reproductive technology (ART) using an empirical score representing the relation of diet with semen quality.

Design

Prospective cohort study.

Setting

Fertility center at an academic medical center.

Patients

We included 296 men (688 semen samples) to identify an empirical dietary pattern and 231 couples (406 ART cycles) to investigate the association of this diet pattern with ART outcomes.

Interventions

Men's diet was assessed at baseline using a validated questionnaire. An empirical dietary pattern reflecting the overall relation of diet with semen quality was identified using reduced rank regression.

Main Outcome Measures

The primary outcome was live birth per treatment cycle. The secondary outcomes were fertilization, implantation, and clinical pregnancy.

Results

Men had a median baseline age and body mass index of 36.8 years and 26.9 kg/m², respectively. Although the empirical diet pattern was significantly associated with all semen parameters, the empirical diet score was not related to any clinical outcome of infertility treatment after ART. The adjusted probabilities of relevant clinical outcomes in the lowest and highest quartiles of the empirical score were 0.62 (0.50-0.73) and 0.55 (0.45-0.66) for implantation, 0.57 (0.46-0.69) and 0.50 (0.40-0.61) for clinical pregnancy, and 0.49 (0.37-0.62) and 0.36 (0.25-0.48) for live birth. Analyses excluding couples with a diagnosis of male factor infertility and, separately, excluding intracytoplasmic sperm injection cycles yielded similar results.

Conclusions

A dietary score representing the overall association of diet with semen quality parameters was not associated with ART outcomes.

Pre-pregnancy menstrual cycle regularity and length and the risk of gestational diabetes mellitus: prospective cohort study

AIMS/HYPOTHESIS

Menstrual cycle dysfunction has been associated with many endocrine-related diseases, but evidence linking menstrual cycle dysfunction with gestational diabetes mellitus (GDM) is scant. The current study investigated the association of pre-pregnancy menstrual cycle regularity and length during adolescence, early adulthood and mid-adulthood with the subsequent risk of GDM.

METHODS

Between 1993 and 2009, we followed 10,906 premenopausal women participating in the Nurses' Health Study II who reported menstrual cycle characteristics during adolescence (age 14-17 years), early adulthood (age 18-22 years) and mid-adulthood (age 29-46 years). Incident GDM was ascertained from a self-reported questionnaire regarding physician diagnosis. Log-binomial models with generalised estimating equations were used to estimate the RRs and 95% CI for the associations between menstrual cycle characteristics and GDM.

RESULTS

We documented 578 incident cases of GDM among 14,418 pregnancies over a 16 year follow-up. After adjusting for potential confounders, women reporting always having irregular menstrual cycles during mid-adulthood had a 65% (95% CI 21, 125%) higher risk of GDM than women reporting very regular cycles. GDM risk was also greater among women reporting that their cycles were usually ≥32 days during mid-adulthood, compared with women reporting cycles between 26 and 31 days (RR 1.42 [95% CI 1.15, 1.75]). The risk of GDM was greater for women whose cycles changed from regular early in their reproductive years to irregular or from <32 days to ≥32 days during mid-adulthood, compared with women whose cycles remained <32 days or regular, respectively.

CONCLUSIONS/INTERPRETATION

Women whose cycles were long or irregular during mid-adulthood, but not in adolescence or young adulthood, were at higher risk of GDM.

Men's dietary patterns in relation to infertility treatment outcomes among couples undergoing in vitro fertilization

PURPOSE(S)

To evaluate the relationship of men's dietary patterns with outcomes of in vitro fertilization (IVF).

METHODS

This is a prospective cohort study including 231 couples with 407 IVF cycles, presented at an academic fertility center from April 2007 to April 2018. We assessed diet with a validated food frequency questionnaire and identified Dietary Pattern 1 and Dietary Pattern 2 using principal component analysis. We evaluated adjusted probability of IVF outcomes across the quartiles of the adherence to two dietary patterns by generalized linear mixed models.

RESULTS

Men had a median age of 36.8 years and BMI of 26.9 kg/m2. Women's median age and BMI were 35.0 years and 23.1 kg/m2, respectively. Adherence to Dietary Pattern 1 (rPearson=0.44) and Dietary Pattern 2 (rPearson=0.54) was positively correlated within couples. Adherence to Dietary Pattern 1 was positively associated with sperm concentration. A 1-unit increase in this pattern was associated with a 13.33 (0.71-25.96) million/mL higher sperm concentration. However, neither Dietary Pattern 1 nor Dietary Pattern 2 was associated with fertilization, implantation, clinical pregnancy, or live birth probabilities.

CONCLUSIONS

Data-derived dietary patterns were associated with semen quality but unrelated to the probability of successful IVF outcomes.

P–106 The evaluation of dietary score representing the overall effect of men’s diet to semen quality on couple’s fertility

Study question

Is men’s diet associated with assisted reproductive technology (ART) outcomes?

Summary answer

An empirical dietary score representing the overall effect of men’s diet on semen quality was unrelated to ART outcomes.

What is known already

Multiple studies have related various aspects of men’s diet to semen quality. Generally, healthier foods, such as fish, vegetables, and fruits, have been related to better semen quality, whereas unhealthy foods, like processed and red meats, have had the opposite relationship. Nevertheless, while bulk semen parameters are important biomarkers of male fertility and a diagnostic cornerstone for male factor infertility, they are imperfect predictors of a couple’s fertility.

Study design, size, duration

Couples presenting to the Massachusetts General Hospital Fertility Center between April 2007 and April 2018 were invited to participate in the Environment and Reproductive Health (EARTH) study, a prospective cohort study. Men’s diet was assessed with a previously validated food frequency questionnaire. A dietary score reflecting the overall relation of men’s food intake with semen quality parameters was empirically derived using reduced rank regression (RRR). The resulting dietary score was related to ART outcomes.

Participants/materials, setting, methods

We used information from 349 men (908 semen samples) to derive the empirical diet pattern and data from 231 couples (407 ART cycles). The primary outcome was the probability of live birth per treatment cycle; secondary outcomes were semen quality, and fertilization, implantation, and clinical pregnancy rates. We evaluated the association between the dietary score and these outcomes using logistic generalized linear mixed models to account for repeated cycles while adjusting for confounders.

Main results and the role of chance

Men had a median baseline age and BMI of 36.8 years and 26.9 kg/m2, respectively. The empirical diet pattern was significantly associated with all semen parameters. One standard deviation increase in the empirical diet pattern was associated with lower volume (–0.10 standard units [95% CI: –0.17 to –0.04]) and to higher sperm total sperm count (0.13 standard units [0.06 to 0.20]), concentration (0.17 standard units [0.10 to 0.24]), total motility (0.14 standard units [0.07 to 0.20]), progressive motility (0.08 standard units [0.01 to 0.15]), and normal morphology (0.18 standard units [0.11 to 0.25]). Couples with men in the lowest quartile of the empirical score were more likely to have a diagnosis of male infertility than couples with men in the highest quartile (49% vs 24%). Despite the association with semen parameters, the empirical diet score was not related to any clinical outcome of infertility treatment with ART. The adjusted probabilities of implantation, clinical pregnancy and live birth in the lowest and highest quartile of the empirical score were 0.62 (0.50–0.73) and 0.55 (0.45–0.66), 0.57 (0.46–0.69) and 0.50 (0.40–0.61), and 0.49 (0.37–0.62) and 0.36 (0.25–0.48), respectively. Analyses excluding couples with a diagnosis of male factor infertility yielded similar results.

Limitations, reasons for caution

We evaluated the relationship only among couples presenting to a fertility center and therefore it is unclear whether findings can be generalized to couples trying to conceive without ART.

Wider implications of the findings: Given ART is a robust intervention including stringent sperm selection procedures, any effect that empirical diet may have on a couple’s chances of conceiving through assisted reproduction is unlikely to reflect the effect of these factors on bulk semen quality parameters.

Trial registration number

The project was funded by ES009718, ES022955, ES026648, and ES000002 from the National Institute of Environmental Health Sciences, and P30DK46200 from the National Institute of Diabetes and Digestive and Kidney Diseases

P–716 The relationship of men’s adherence to the Mediterranean diet with sperm parameters and outcomes of assisted reproductive technologies

Study question

Is men’s adherence to the Mediterranean diet (MD) associated with sperm parameters and couples’ outcomes of assisted reproductive technologies (ART)?

Summary answer

Higher men’s adherence to the MD was associated with an increased probability of clinical pregnancy and live birth among couples undergoing ART.

What is known already

There is growing literature supporting the hypothesis that some nutrients, foods, and dietary patterns may be related to sperm quality and fertility. However, no previous studies analyzed the relationship of men’s adherence to the Mediterranean diet with sperm parameters and ART outcomes in the same cohort.

Study design, size, duration

The Environmental and Reproductive Health (EARTH) Study is a prospective preconception cohort of couples seeking fertility treatment at the Massachusetts General Hospital Fertility Center (Boston, USA). This analysis includes 314 men and their female partner, who underwent 791 ART cycles (2007–2020). Diet intake was measured by a validated semi-quantitative food frequency questionnaire completed prior to ART. Men’s adherence to the MD was estimated using the Trichopoulou score.

Participants/materials, setting, methods

Primary outcomes included: conventional sperm parameters (volume, sperm count, concentration, motility, and morphology), and ART outcomes (implantation, clinical pregnancy, and live birth). We estimated the marginal means and 95% confidence interval (95%CI) for semen parameters and the probability of ART (95%CI) by employing generalized linear mixed models while adjusting for several potential confounders. Sensitivity analyses by changing the cut-off points of adherence to the MD were tested.

Main results and the role of chance

At baseline, men had a median (IQR) age of 35.6 (32.6, 38.8) years and a BMI of 26.7 (24.0, 29.4) kg/m2. Female partner age median (IQR) was 35.0 years (32.0, 38.0) and BMI 23.3 (21.3, 26.6) kg/m2. Couples were mostly white and had never smoked. Men’s adherence to the MD was not associated with seminal parameters in the multivariable-adjusted models but it was related to a higher probability of clinical pregnancy and live birth. The predicted marginal proportions and confidence intervals among men in the lowest compared with the highest quartile of adherence to the MD were 0.25 (0.14, 0.40), 0.55 (0.41, 0.68) for clinical pregnancy (P-trend=0.005), and 0.19 (0.10, 0.32), 0.42 (0.30, 0.55) for live birth (P-trend=0.014). Male partner MD dietary pattern scores were unrelated to the probability of implantation. Sensitivity analyses using tertiles and quintiles of men’s adherence to the MD showed similar associations.

Limitations, reasons for caution

Although we have adjusted our models by several potential confounding factors, residual confounding cannot be ruled out, and therefore our results should be interpreted with caution. The findings may not be generalizable to other populations or couples attempting conception without ART.

Wider implications of the findings: According to our knowledge, this is the first study suggesting that adherence to MD could be suitable dietary guidance for men whose partners are undergoing infertility treatment.

Trial registration number

Not applicable

Pre-pregnancy Dietary Intake of Omega-3 and Omega-6 Fatty Acids and the Risk of Hypertensive Disorders of Pregnancy

Objectives

To evaluate whether pre-pregnancy intakes of omega-3 and omega-6 fatty acids prevent HDP.

Methods

We followed 11,535 women from the Nurses' Health Study-II free of chronic disease that filled out food frequency questionnaires starting in 1991 before their 16,892 singleton pregnancies. Intakes of omega-3 fatty acids (alpha-linolenic acid[ALA] + long-chain omega-3 [LCN-3]) and omega-6 (linoleic acid [LA] + arachidonic acid[ARA]). In 2009, participants reported history of preeclampsia and GHTN. The relative risk (95%CI) of HDP across quintiles of intakes of omega-3 and omega-6 were estimated by log-binomial regression model using generalized estimating equation to account for repeated pregnancies from the same woman and adjusted for age at pregnancy, year of pregnancy, and pre-pregnancy: BMI, physical activity, smoking, infertility diagnosis, marital status, race, parity, multivitamin use, concurrent gestational diabetes, and preeclampsia at baseline.

Results

During 18 years of follow-up, there were 495 pregnancies with preeclampsia (2.9%) and 561 pregnancies (3.3%) with GHTN. Mean (SD) age at pregnancy was 34.6 (3.9) years. Intakes of total omega-6 and total omega-3 fatty acids before pregnancy were unrelated with the risk of either HDP. From individual omega subtypes, only ARA had a marginally significant relation to higher risk of GHTN. Women in the highest quintile of ARA had 43% increased risk of GHTN (CI: 1.00–2.04) compared to women in the lowest quintile of intake. Intakes of the remaining subtypes, LA, LCN-3, and ALA were not associated to HDP risk. When we restricted the analysis to a closer window of exposure among 5,208 women with diet assessment one year before pregnancy, only intakes of LCN-3 (RR = 0.55, CI:0.33–0.91) and LA (RR = 0.54, CI: 0.29,0.99) were associated with a lower risk of preeclampsia, comparing women in the highest versus the lowest quintile of intake.

Conclusions

Dietary intake of long-chain omega-3 fatty acid and linoleic acid one year before pregnancy was associated with a reduced risk of preeclampsia. The extent to which long-chain omega-3 prevents preeclampsia may be more relevant in a window of exposure closer to pregnancy.

Funding Sources

National Institutes of Health grants U01-HL145386–01, UM1-CA176726, P30-DK046200, and R00ES026648.

Complete androgen insensitivity syndrome and anti-Müllerian hormone levels before and after laparoscopic gonadectomy

We report cases of two sisters with complete androgen insensitivity syndrome (CAIS). A complete female appearance, blind-ending vagina, and testes in the pelvis are characteristics of CAIS. Prophylactic laparoscopic gonadectomy was performed in both cases. Anti-Müllerian hormone (AMH) level is known to be very high in patients with CAIS; AMH is secreted by Sertoli cells and testosterone suppresses the secretion. In our cases, serum AMH was very high before gonadectomy and dramatically decreased after gonadectomy. AMH could be the diagnostic feature for patients with CAIS.