Preconception maternal lipoprotein levels in relation to fecundability

Hyperlipidemia is negatively associated with pregnancy outcomes in patients following frozen-thawed embryo transfer: A retrospective study

Background and Aims

It is demonstrated that lipid metabolism disorders are associated with the reproductive performances of assisted reproductive technology. However, it is little known whether hyperlipidemia is associated with the endometrial receptivity and pregnancy outcomes of patients undergoing frozen-thawed embryo transfer (FET).

Methods

This was a retrospective analysis involving 554 infertile women undergoing FET. The patients were divided into the hyperlipidemia group (n = 224) and control group (n = 320) based on the levels of serum lipids. The clinical and laboratory indexes between the two groups were compared. Meanwhile, the stratified analysis based on body mass index (BMI) and endometrial preparation protocols was performed. The independent samples t-test, Mann-Whitney U test, χ2 test and multiple logistic regression analysis were used to compare and analyze the data.

Results

The patients with hyperlipidemia had significantly higher serum lipids levels and BMI and lower clinical pregnancy and implantation rates than those with normal blood lipids (p < 0.05). The impact of hyperlipidemia on pregnancy outcomes was independent of BMI. The multiple logistic regression analysis showed that higher cholesterol was associated with lower pregnancy rate and implantation rate (p < 0.05). Regardless of blood lipid levels, the patients undergoing the hormone replacement therapy (HRT) protocol had higher estradiol levels and lower progesterone levels compared with the stimulated cycles (STC) (p < 0.05). Moreover, the clinical pregnancy rate and implantation rate of the HRT protocol were higher than those of the STC, although there was no significant difference between the two.

Conclusion

Hyperlipidemia especially higher cholesterol has a negative effect on the pregnancy outcomes of the patients undergoing FET. Actively implementing lipid-lowering treatment and the HRT protocol seem more friendly for these patients.

Astaxanthin supplementation impact on insulin resistance, lipid profile, blood pressure, and oxidative stress in polycystic ovary syndrome patients: A triple-blind randomized clinical trial

Astaxanthin (ASX) is a natural carotenoid compound found in several of microorganisms and seafood. It may have numerous therapeutic benefits for polycystic ovarian syndrome (PCOS) patients. The aim of this study was to investigate the effect of ASX on lipid profile, insulin resistance (IR), blood pressure (BP), and oxidative stress (OS) levels in infertile PCOS patients. Overall, 58 infertile women with diagnosed PCOS participated in this triple-blind randomized clinical trial. They were randomly assigned to two groups, taking either a placebo or ASX (2 × 6 mg/day) for 8 weeks. Blood serum samples were collected from patients before and after the intervention. Fasting Insulin (FI), fasting blood glucose (FBS), OS markers (malondialdehyde [MDA], superoxide dismutase [SOD], and total antioxidant capacity [TAC]), and lipid profiles were evaluated in serum. Moreover, based on the relevant formula, several indices associated with IR were calculated. BP was also assessed at the start and end of the study. After 8 weeks of ASX consumption, a significant reduction was observed in fasting blood sugar, HOMA-IR, FI, MDA, low-density lipoprotein-cholesterol, and TC/HDL-C. Conversely, ASX significantly increased TAC, HDL-C, and QUICKI. After adjusting the analysis for the baseline values of age, body mass index, and biochemical parameters, non-significant values were obtained for QUICKI and FI, along with no changes in other findings. Overall, ASX appears to be an effective and safe supplement that alleviates insulin metabolism, lipid profile parameters, and OS in infertile PCOS patients.

Sex differences in lipids: A life course approach

Differences between men and women in lipids and lipoproteins are observed in distribution and trajectory from infancy to adulthood in the general population. However, these differences are more pronounced in hereditary lipid disorders such as familial hypercholesterolemia (FH) when absolute cholesterol levels are higher from birth onwards. In the early life course, girls compared to boys have higher low-density lipoprotein cholesterol (LDL-C) levels and total cholesterol, while high-density lipoprotein cholesterol (HDL-C) levels are similar. In early adulthood to middle-age, women have lower LDL-C and higher HDL-C levels, as LDL-C levels increase and HDLC levels decrease in men. In the elderly, all lipids - total cholesterol, LDL-C, HDL-C and triglyceride levels decrease but are more pronounced in men. Lipid levels are also affected by specific transitions in girls/women such as the menstrual cycle, pregnancy, breastfeeding and menopause. Lipid levels fluctuate during the menstrual cycle. During pregnancy a physiological increase of LDL-C and even a larger increase in triglyceride levels are observed. Pregnancy has a double impact on LDL-C accumulation in women with FH as they have to stop statins, and the absolute increase in LDL-C is higher than in women without FH. In the menopausal transition, women develop a more adverse lipid profile. Therefore, it is important to take into account both sex and the life course when assessing a lipid profile.

The Association between Circulating Lipids and Female Infertility Risk: A Univariable and Multivariable Mendelian Randomization Analysis

BACKGROUND

Although observational studies have demonstrated that blood lipids are associated with female infertility, the causality of this association remains unclear. We performed a univariable and multivariable Mendelian randomization (MR) analysis to evaluate the causal relationship between blood lipids and female infertility.

METHODS

Single-nucleotide polymorphisms associated with lipid traits in univariate analysis were obtained from the Million Veteran Program (MVP) and Global Lipids Genetics Consortium (GLGC), involving up to 215,551 and 188,577 European individuals, respectively. Blood lipids in multivariate analysis were obtained from the latest genome-wide association study meta-analysis with lipid levels in 73 studies encompassing >300,000 participants. Data on female infertility were obtained from the FinnGen Consortium R6 release, which included 6481 samples and 75,450 controls. Subsequently, MR analysis was performed using inverse variance-weighted (IVW), weighted median, weighted-mode, simple-mode and MR-Egger regression to demonstrate the causal relationship between lipids and female infertility.

RESULTS

After controlling confounding factors including body mass index and age at menarche, two-sample MR demonstrated that genetically predicted LDL-C and TC were causally associated with the risk of female infertility (When the genetic instruments come from the MVP database, LDL-C and female infertility, IVW OR: 1.13, 95% CI: 1.001-1.269, p = 0.047; TC and female infertility, IVW OR: 1.16, 95% CI: 1.018-1.317, p = 0.025, and when the genetic instruments came from the GLGC database, LDL-C and female infertility, IVW OR: 1.10, 95% CI: 1.008-1.210, p = 0.033; TC and female infertility, IVW OR: 1.14, 95% CI: 1.024-1.258, p = 0.015). However, the IVW estimate showed that HDL-C was not significantly associated with the risk of female infertility (when the genetic instruments came from the MVP database, IVW OR: 1.00, 95% CI: 0.887-1.128, p = 0.999; when the genetic instruments came from the GLGC database, IVW OR: 1.00, 95% CI: 0.896-1.111, p = 0.968). The multivariable MR analysis also provided evidence that LDL-C (OR: 1.12, 95% CI: 1.006-1.243, p = 0.042) was significantly associated with the risk of female infertility after considering the correlation of all lipid-related traits.

CONCLUSION

These findings support a causal relationship between increased LDL-cholesterol and increased female infertility risk. Furthermore, the association between lipid-related traits and female infertility risk merits more studies.

Implications of High-Density Cholesterol Metabolism for Oocyte Biology and Female Fertility

Cholesterol is an essential component of animal cells. Different regulatory mechanisms converge to maintain adequate levels of this lipid because both its deficiency and excess are unfavorable. Low cell cholesterol content promotes its synthesis and uptake from circulating lipoproteins. In contrast, its excess induces the efflux to high-density lipoproteins (HDL) and their transport to the liver for excretion, a process known as reverse cholesterol transport. Different studies suggest that an abnormal HDL metabolism hinders female fertility. HDL are the only lipoproteins detected in substantial amounts in follicular fluid (FF), and their size and composition correlate with embryo quality. Oocytes obtain cholesterol from cumulus cells via gap junctions because they cannot synthesize cholesterol de novo and lack HDL receptors. Recent evidence has supported the possibility that FF HDL play a major role in taking up excess unesterified cholesterol (UC) from the oocyte. Indeed, genetically modified mouse models with disruptions in reverse cholesterol transport, some of which show excessive circulating UC levels, exhibit female infertility. Cholesterol accumulation can affect the egg´s viability, as reported in other cell types, and activate the plasma membrane structure and activity of membrane proteins. Indeed, in mice deficient for the HDL receptor Scavenger Class B Type I (SR-B1), excess circulating HDL cholesterol and UC accumulation in oocytes impairs meiosis arrest and hinders the developmental capacity of the egg. In other cells, the addition of cholesterol activates calcium channels and dysregulates cell death/survival signaling pathways, suggesting that these mechanisms may link altered HDL cholesterol metabolism and infertility. Although cholesterol, and lipids in general, are usually not evaluated in infertile patients, one study reported high circulating UC levels in women showing longer time to pregnancy as an outcome of fertility. Based on the evidence described above, we propose the existence of a well-regulated and largely unexplored system of cholesterol homeostasis controlling traffic between FF HDL and oocytes, with significant implications for female fertility.

Lipid metabolism and endometrial receptivity

BACKGROUND

Obesity has now been recognized as a high-risk factor for reproductive health. Although remarkable advancements have been made in ART, a considerable number of infertile obese women still suffer from serial implantation failure, despite the high quality of embryos transferred. Although obesity has long been known to exert various deleterious effects on female fertility, the underlying mechanisms, especially the roles of lipid metabolism in endometrial receptivity, remain largely elusive.

OBJECTIVE AND RATIONALE

This review summarizes current evidence on the impacts of several major lipids and lipid-derived mediators on the embryonic implantation process. Emerging methods for evaluating endometrial receptivity, for example transcriptomic and lipidomic analysis, are also discussed.

SEARCH METHODS

The PubMed and Embase databases were searched using the following keywords: (lipid or fatty acid or prostaglandin or phospholipid or sphingolipid or endocannabinoid or lysophosphatidic acid or cholesterol or progesterone or estrogen or transcriptomic or lipidomic or obesity or dyslipidemia or polycystic ovary syndrome) AND (endometrial receptivity or uterine receptivity or embryo implantation or assisted reproductive technology or in vitro fertilization or embryo transfer). A comprehensive literature search was performed on the roles of lipid-related metabolic pathways in embryo implantation published between January 1970 and March 2022. Only studies with original data and reviews published in English were included in this review. Additional information was obtained from references cited in the articles resulting from the literature search.

OUTCOMES

Recent studies have shown that a fatty acids-related pro-inflammatory response in the embryo-endometrium boundary facilitates pregnancy via mediation of prostaglandin signaling. Phospholipid-derived mediators, for example endocannabinoids, lysophosphatidic acid and sphingosine-1-phosphate, are associated with endometrial receptivity, embryo spacing and decidualization based on evidence from both animal and human studies. Progesterone and estrogen are two cholesterol-derived steroid hormones that synergistically mediate the structural and functional alterations in the uterus ready for blastocyst implantation. Variations in serum cholesterol profiles throughout the menstrual cycle imply a demand for steroidogenesis at the time of window of implantation (WOI). Since 2002, endometrial transcriptomic analysis has been serving as a diagnostic tool for WOI dating. Numerous genes that govern lipid homeostasis have been identified and, based on specific alterations of lipidomic signatures differentially expressed in WOI, lipidomic analysis of endometrial fluid provides a possibility for non-invasive diagnosis of lipids alterations during the WOI.

WIDER IMPLICATIONS

Given that lipid metabolic dysregulation potentially plays a role in infertility, a better understanding of lipid metabolism could have significant clinical implications for the diagnosis and treatment of female reproductive disorders.

Metabolic health status and fecundability in a Singapore preconception cohort study

BACKGROUND

Obesity compromises metabolic health and female fertility, yet not all obese women are similar in metabolic status. The extent to which fecundability is influenced by the metabolic health status of women who are overweight or obese before conception is unknown.

OBJECTIVE

This study aimed to: (1) determine the metabolic health status, and (2) examine the association between metabolic health status and fecundability of overweight and obese women trying to conceive in the Singapore PREconception Study of long-Term maternal and child Outcomes cohort study.

STUDY DESIGN

We conducted a prospective preconception cohort study of Asian women (Chinese, Malay, and Indian) aged 18 to 45 years trying to conceive who were treated from 2015 to 2017 in KK Women's and Children's Hospital in Singapore (n=834). We defined women to have metabolically unhealthy status if they: (1) met 3 or more modified Joint Interim Statement metabolic syndrome criteria; or (2) had homeostasis model assessment-insulin resistance index ≥2.5. Body mass index was categorized as normal (18.5-22.9 kg/m2), overweight (23-27.4 kg/m2), or obese (≥27.5 kg/m2) on the basis of cutoff points for Asian populations. Fecundability was measured by time to pregnancy in menstrual cycles within a year of enrolment. Discrete-time proportional hazards models were used to estimate fecundability odds ratios, with adjustment for confounders and accounting for left truncation and right censoring.

RESULTS

Of 232 overweight women, 28 (12.1%) and 25 (10.8%) were metabolically unhealthy by metabolic syndrome ≥3 criteria and homeostasis model assessment-insulin resistance ≥2.5, respectively. Of 175 obese women, 54 (30.9%) and 93 (53.1%) were metabolically unhealthy by metabolic syndrome ≥3 criteria and homeostasis model assessment-insulin resistance ≥2.5, respectively. Compared with metabolically healthy normal-weight women, lower fecundability was observed in metabolically unhealthy overweight women on the basis of metabolic syndrome criteria (fecundability odds ratios, 0.38 [95% confidence interval, 0.15-0.92]) and homeostasis model assessment-insulin resistance (fecundability odds ratios, 0.68 [95% confidence interval, 0.33-1.39]), with metabolic syndrome criteria showing a stronger association. Metabolically unhealthy obese women showed lower fecundability than the healthy normal-weight reference group by both metabolic syndrome (fecundability odds ratios, 0.35; 95% confidence interval, 0.17-0.72) and homeostasis model assessment-insulin resistance criteria (fecundability odds ratios, 0.43; 95% confidence interval, 0.26-0.71). Reduced fecundability was not observed in overweight or obese women who showed healthy metabolic profiles by either definition.

CONCLUSION

Overweight or obesity was not synonymous with having metabolic syndrome or insulin resistance. In our preconception cohort, metabolically unhealthy overweight and obese women showed reduced fecundability, unlike their counterparts who were metabolically healthy. These findings suggest that metabolic health status, rather than simply being overweight and obese per se, plays an important role in fecundability.

Associations between dyslipidaemia and pregnancy outcomes in the first complete cycle of IVF/ICSI: a real-world analysis

RESEARCH QUESTION

Are there associations between dyslipidaemia and pregnancy outcomes in the first complete cycle of IVF/intracytoplasmic sperm injection (ICSI)?

DESIGN

This long-term, retrospective real-world analysis involved 5030 infertile women who underwent a first complete IVF/ICSI cycle between January 2015 and October 2020. They were categorized into dyslipidaemia (n = 1903) and control (n = 3127) groups according to serum lipid concentrations before ovarian stimulation. Propensity score matching and multivariable logistic regression were used to control for confounding variables.

RESULTS

In the raw cohort, women with dyslipidaemia had a significantly increased late miscarriage rate (P = 0.039), decreased term birth rate (P = 0.002) and decreased live birth rate (P = 0.005) compared with non-dyslipidaemic women. In the propensity score-matched cohort, the term birth rate (P = 0.038) and live birth rate (P = 0.044) were significantly lower in the dyslipidaemia group (n = 1686) than the controls (n = 1686). Multivariable logistic regression indicated that infertile women with dyslipidaemia (P = 0.026) and elevated serum total cholesterol concentrations (total cholesterol ≥5.20 mmol/l; P = 0.028) were significantly less likely to have a live birth. Rates of late miscarriage (P = 0.027), term birth (P = 0.003) and live birth (P = 0.010) differed significantly among women with normal, borderline increased and increased serum lipid concentrations. Compared with controls, women with increased serum lipid concentrations had a significantly higher late miscarriage rate, lower term birth rate and lower live birth rate. Women with increased serum lipid concentrations were significantly less likely than controls to have a live birth.

CONCLUSIONS

Dyslipidaemia, total cholesterol ≥5.20 mmol/l and degrees of elevated serum lipid concentrations are negatively associated with live birth rate in the first complete IVF/ICSI cycle in infertile women.

Dyslipidemia Is Negatively Associated With the Cumulative Live-Birth Rate in Patients Without PCOS Following IVF/ICSI

Objective: To evaluate the effect of dyslipidemia on the cumulative live-birth rate (cLBR) in patients without polycystic ovary syndrome (PCOS) undergoing in vitro fertilization/intracytoplasmic sperm injection-embryo transfer (IVF/ICSI-ET) cycles. Methods: A total of 1,132 patients from the Yantai Yuhuangding Hospital Affiliated to Qingdao University from January 2016 to December 2017 were retrospectively included. The subjects were distributed into two groups based on their lipid profiles, namely, dyslipidemia group (n = 195) and control group (n = 937). The clinical and laboratory parameters of the two groups were analyzed, and a multivariate logistic regression analysis of the cLBR was conducted. In addition, subgroup analysis was carried out to avoid deviation according to the body mass index (BMI). Results: Patients with dyslipidemia had significantly greater BMI and longer duration of infertility, as well as lower antral follicle count and basal follicle-stimulating hormone level compared with patients without dyslipidemia. Stratified analysis showed that dyslipidemia was associated with a significantly higher total gonadotrophin dosage required for ovarian stimulation as well as lower number of oocytes retrieved, independent of obesity. The live-birth rate in fresh cycle and cLBR were higher in the control group, although the difference between the groups was not significant (54.9% vs. 47.3%, p = 0.116; 67.6% vs. 62.1%, p = 0.138). However, multivariate logistic regression analysis adjusting for potential confounders showed that dyslipidemia was negatively associated with cLBR (OR, 0.702, 95% CI, 0.533-0.881, p = 0.044). Conclusion: Our findings demonstrate for the first time that dyslipidemia has a deleterious impact on cLBR, independent of obesity, in non-PCOS population considered to have good prognosis. Assessment of serum lipid profiles as well as the provision of nutritional counseling is essential for increasing successful outcomes in assisted reproductive techniques.

Dietary Energy Density and Fertility: Results from the Lifestyle and Fertility Study

BACKGROUND

Diet is a modifiable lifestyle factor linked with fertility in a growing number of studies.

OBJECTIVE

The objective of this study was to evaluate the association between dietary energy density (ED), a summary measure of diet quality that estimates the amount of energy per unit food (kcal/g) consumed, and conception and pregnancy outcomes.

METHODS

A prospective cohort study of couples planning their first pregnancy was conducted in the Northeast region of the USA. Dietary data were collected prior to conception via 3 unannounced interviewer-administered 24-h dietary recalls. Multivariable-adjusted logistic regression (ORs and Cox proportional hazards models [RR] and 95% CIs) were estimated for continuous and categorical (tertile [T]) variables of dietary ED.

RESULTS

The majority of women (n = 80; 61%) achieved clinical pregnancy. Median time to conception of a clincal pregnancy(TTC) for those who conceived was 4.64 mo with an IQR of 4.37 mo. ED modeled as a continuous variable was not associated with clinical pregnancy, live birth, or TTC after controlling for race, physical activity, and male partner's ED. When ED was categorized to consider nonlinear associations, 60%, 73%, and 50% of the participants in the tertiles (from lowest ED to highest) achieved clinical pregnancy. In multivariable logistic analyses with the middle group as the referent (ED = 1.37-1.60), membership in the highest ED group (ED >1.60) was associated with lower odds of clinical pregnancy (OR = 0.30; 95% CI: 0.11, 0.81, P = 0.02). In Cox proportional hazards analyses, membership in the highest ED group was associated with significantly longer TTC compared with the middle category (HR = 0.41; 95% CI: 0.21,0.82, P = 0.01).

CONCLUSIONS

These results suggest that high dietary ED is associated with reduced fertility.This study evaluated associations between dietary energy density and the probability of conceiving clinical pregnancy, having a live birth, and the time to conception among couples planning pregnancy.

Adiposity is associated with anovulation independent of serum free testosterone: A prospective cohort study

BACKGROUND

Obesity, a body mass index (BMI) ≥30 kg/m2 , is linked to infertility, potentially through a greater risk of anovulation due to elevated androgens. Yet, previous studies have not directly assessed the impact of adiposity, or body fat, on anovulation in the absence of clinical infertility.

OBJECTIVE

To characterise the associations between adiposity and anovulation among women menstruating on a regular basis.

METHODS

Women from the EAGeR trial (n = 1200), a randomised controlled trial of low-dose aspirin and pregnancy loss among women trying to conceive, were used to estimate associations between adiposity and incident anovulation. Participants completed baseline questionnaires and anthropometry, and provided blood specimens. Women used fertility monitors for up to six consecutive menstrual cycles, with collection of daily first morning voids for hormone analysis in the first two menstrual cycles for prospective assessment of anovulation. Anovulation was assessed by urine pregnanediol glucuronide or luteinising hormone concentration or the fertility monitor. Weighted mixed-effects log-binomial regression was used to estimate associations between measures of adiposity and incident anovulation, adjusted for free (bioavailable) testosterone, anti-Mullerian hormone (AMH), serum lipids, and demographic and life style factors.

RESULTS

343 (28.3%) women experienced at least one anovulatory cycle. Anovulation risk was higher per kg/m2 greater BMI (relative risk [RR] 1.03, 95% confidence interval (CI) 1.01, 1.04), cm waist circumference (RR 1.01, 95% CI 1.00, 1.02), mm subscapular skinfold (RR 1.02, 95% CI 1.01, 1.03), and mm middle upper arm circumference (RR 1.04, 95% CI 1.01, 1.06) adjusted for serum free testosterone, AMH, lipids, and other factors.

CONCLUSIONS

Adiposity may be associated with anovulation through pathways other than testosterone among regularly menstruating women. This may account in part for reported associations between greater adiposity and infertility among women having menstrual cycles regularly. Understanding the association between adiposity and anovulation might lead to targeted interventions for preventing infertility.

Serum Lipid Levels and Treatment Outcomes in Women Undergoing Assisted Reproduction: A Retrospective Cohort Study

OBJECTIVE

To evaluate associations between serum lipid levels and treatment outcomes in women undergoing assisted reproduction.

MATERIALS AND METHODS

The study included 2011 women who underwent in vitro fertilization/intracytoplasmic sperm injection with fresh embryo transfer. Serum lipid evaluation included total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG). Ovarian stimulation outcomes included endometrial thickness and the number of oocytes retrieved, and reproductive outcomes included live birth, clinical pregnancy, and miscarriage.

RESULTS

Higher HDL-C quartiles were associated with more oocytes retrieved. Lower TC (quartile 1 odds ratio [OR] 1.59 [1.21-2.08], quartile 3 OR 1.36 [1.04-1.77]), LDL-C (quartile 1 OR 1.41 [1.07-1.86]), and TG (quartile 2 OR 1.39 [1.06-1.84]) were independently associated with clinical pregnancy after adjusting for potential confounders. Lower LDL-C (quartile 1 OR 2.22 [1.58-3.13], quartile 2 OR 1.78 [1.27-2.50], quartile 3 OR 1.51 [1.07-2.13]), TC (quartile 1 OR 1.39 [1.00-1.93]), TG (quartile 1 OR 1.44 [1.03-2.03], quartile 2 OR 1.46 [1.04-2.04], quartile 3 OR 1.44 [1.04-1.99]), and higher HDL-C (quartile 2 OR 0.71 [0.51-0.99]) were independently associated with live birth. Higher LDL-C (quartile 1 OR 0.44 [0.30-0.66], quartile 2 OR 0.49 [0.33-0.73], quartile 3 OR 0.63 [0.43-0.94]) and lower HDL-C (quartile 1 OR 1.60 [1.07-2.39]) were independently associated with miscarriage.

CONCLUSIONS

Serum lipid levels were associated with treatment outcomes in women undergoing assisted reproduction.

Activation of nuclear factor-kappa B subunits c-Rel, p65 and p50 by plasma lipids and fatty acids across the menstrual cycle

This study focused on a comprehensive analysis of the canonical activation pathway of the redox-sensitive transcription factor nuclear factor-kappa B (NF-κB) in peripheral blood mononuclear cells, addressing c-Rel, p65 and p50 activation in 28 women at early (T1) and late follicular (T2) and mid (T3) and late luteal (T4) phase of the menstrual cycle, and possible relations with fasting plasma lipids and fatty acids. For the first time, strong inverse relations of c-Rel with apolipoprotein B were observed across the cycle, while those with LDL cholesterol, triglycerides as well as saturated (SFA), particularly C14-C22 SFA, monounsaturated (MUFA), and polyunsaturated fatty acids (PUFA) clustered at T2. In contrast, p65 was positively related to LDL cholesterol and total n-6 PUFA, while p50 did not show any relations. C-Rel was not directly associated with estradiol and progesterone, but data suggested an indirect C22:5n-3-mediated effect of progesterone. Strong positive relations between estradiol and individual SFA, MUFA and n-3 PUFA at T1 were confined to C18 fatty acids; C18:3n-3 was differentially associated with estradiol (positively) and progesterone (inversely). Given specific roles of c-Rel activation in immune tolerance, inhibition of c-Rel activation by higher plasma apolipoprotein B and individual fatty acid concentrations could have clinical implications for female fertility.

Women's age and total motile normal morphology sperm count predict fecundability: a prospective cohort study

OBJECTIVE

This study investigated the role of women's age, serum anti-Müllerian hormone (AMH) level and semen parameters in predicting fecundability.

METHODS

This was a prospective cohort study on couples attending for preconceptional health check. Occurrence of conception at 1 year after ceasing contraception and time to pregnancy were noted by telephone follow-up. The women's age, serum AMH level and total motile normal morphology sperm count (TMNC) were compared between those who conceived and those who did not after 1 year; their independent predictive value on conception at 1 year was analysed by logistic regression. Among those conceiving within 1 year, Spearman's correlations between time to pregnancy and the clinical parameters were studied.

RESULTS

Of the 100 couples analysed, we found younger age of the women (p=0.008), higher serum AMH level (p=0.038) and higher TMNC (p=0.015) in those that conceived within 1 year. Multivariate logistic regression found that women's age (OR 0.867, 95% CI 0.761 to 0.988, p=0.032) and TMNC (OR 1.089, 95% 1.001-1.185, p=0.047), but not serum AMH level, significantly predicted conception within 1 year. Among those that conceived within 1 year, none of the parameters analysed were correlated with time to pregnancy within 1 year.

CONCLUSIONS

Women's age and TNMC are significant independent predictors of conception within 1 year. No parameter was shown to predict the time to pregnancy within 1 year. This finding can aid preconceptional counselling of couples who are planning for pregnancy.

Women Living with Familial Hypercholesterolemia: Challenges and Considerations Surrounding Their Care

PURPOSE OF REVIEW

To highlight the gender-based differences in presentation and disparities in care for women with familial hypercholesterolemia (FH).

RECENT FINDINGS

Women with FH experience specific barriers to care including underrepresentation in research, significant underappreciation of risk, and interrupted therapy during childbearing. National and international registry and clinical trial data show significant healthcare disparities for women with FH. Women with FH are less likely to be on guideline-recommended high-intensity statin medications and those placed on statins are more likely to discontinue them within their first year. Women with FH are also less likely to be on regimens including non-statin agents such as PCSK9 inhibitors. As a result, women with FH are less likely to achieve target low-density lipoprotein cholesterol (LDL-C) targets, even those with prior atherosclerotic cardiovascular disease (ASCVD). FH is common, under-diagnosed, and under-treated. Disparities of care are more pronounced in women than men. Additionally, FH weighs differently on women throughout the course of their lives starting from choosing contraceptives as young girls along with lipid-lowering therapy, timing pregnancy, choosing breastfeeding or resumption of therapy, and finally deciding goals of care during menopause. Early identification and appropriate treatment prior to interruptions of therapy for childbearing can lead to marked reduction in morbidity and mortality. Women access care differently than men and increasing awareness among all providers, especially cardio-obstetricians, may improve diagnostic rates. Understanding the unique challenges women with FH face is crucial to close the gaps in care they experience.

Metabolic Syndrome and the Effectiveness of Low-dose Aspirin on Reproductive Outcomes

BACKGROUND

Metabolic syndrome is associated with increases in both inflammation and aspirin resistance, but effectiveness of aspirin in improving reproductive health among women with metabolic syndrome is unknown. We evaluated the effectiveness of low-dose aspirin in improving reproductive outcomes across metabolic syndrome score.

METHODS

The EAGeR trial randomly assigned 1228 women with a history of pregnancy loss to receive 81 mg aspirin or placebo for up to six menstrual cycles of attempting pregnancy and, if they became pregnant, throughout pregnancy. We assessed components of metabolic syndrome at enrollment, including: waist circumference ≥88 cm, triglycerides ≥150 mg/dl, high-density lipoprotein ≤50 mg/dl, blood pressure ≥130 mmHg systolic or ≥85 mmHg diastolic, and glucose ≥100 mg/dl. We summed components to calculate metabolic syndrome score.

RESULTS

A total of 229 participants (20%) met full criteria for metabolic syndrome, 207 (18%) had two components, 366 (31%) one component, and 372 (32%) no components. Among those without any component of metabolic syndrome, aspirin was associated with 10.7 [95% confidence interval (CI) = 1.2, 20.2] more pregnancies and 13.7 (95% CI = 3.3, 24.0) more live births per 100 couples. Effects were attenuated as metabolic syndrome score increased and we observed no clear effect of aspirin on pregnancy or live birth among women with metabolic syndrome.

CONCLUSIONS

Low-dose aspirin is most effective in increasing pregnancy and live birth among women with no or few components of metabolic syndrome. Reduced effectiveness among women with metabolic syndrome may be due to differences in effective dose or aspirin resistance.

A method to visualize a complete sensitivity analysis for loss to follow-up in clinical trials

Loss to follow-up occurs in randomized controlled trials. Missing data methods, including multiple imputation (MI), can be used but often rely upon untestable assumptions. Sensitivity analysis can quantify violations of these assumptions. Since an adequate sensitivity analysis requires evaluation of multiple scenarios, presenting this information in an easily interpretable manner is challenging.

We propose to graphically represent a thorough sensitivity analysis displaying all possible outcomes for loss to follow-up in randomized controlled trial data relating a completely observed binary exposure to a binary outcome. We describe plausible results under different missingness mechanisms using data from the EAGeR Trial (n = 1228) on low-dose aspirin versus placebo on pregnancy and live birth, in which 140 participants had early withdrawal. For the effect of aspirin on live birth, sensitivity analysis risk ratios (RR) for all potential outcome scenarios ranged from 0.88 to 1.34, applicable to any possible missingness mechanism. MI produced RR = 1.10; 95% confidence interval: (0.98, 1.22). RRs from individual imputations ranged from 1.04 to 1.16, the range of results that could have been observed if data were missing at random. Under this mechanism, the conclusions about the efficacy of low-dose aspirin could have been sensitive to the missing outcome data. Rather than limiting sensitivity analysis for loss to follow-up to a few scenarios that can be presented tabularly, results of a complete sensitivity analysis can be presented in a single plot, which should be implemented in all studies with missing outcome data to convey certainty or uncertainty, confidence or caution.

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Loss to follow-up can cause selection bias in randomized controlled trials.

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Sensitivity analysis is often limited to a few scenarios presented tabularly.

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A complete sensitivity analysis is demonstrated for binary exposure and outcomes.

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All possible and probable outcomes can be graphically displayed in a single plot.

Aspirin or heparin or both for improving pregnancy outcomes in women with persistent antiphospholipid antibodies and recurrent pregnancy loss

BACKGROUND

Aspirin and heparin are widely used as preventive strategy to reduce the high risk of recurrent pregnancy loss in women with antiphospholipid antibodies (aPL). This review supersedes a previous, out-of-date review that evaluated all potential therapies for preventing recurrent pregnancy loss in women with aPL. The current review focusses on a narrower scope because current clinical practice is restricted to using aspirin or heparins, or both for women with aPL in an attempt to reduce pregnancy complications.

OBJECTIVES

To assess the effects of aspirin or heparin, or both for improving pregnancy outcomes in women with persistent (on two separate occasions) aPL, either lupus anticoagulant (LAC), anticardiolipin (aCL) or aβ₂-glycoprotein-I antibodies (aβ₂GPI) or a combination, and recurrent pregnancy loss (two or more, which do not have to be consecutive).

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (3 June 2019), and reference lists of retrieved studies. Where necessary, we attempted to contact trial authors.

SELECTION CRITERIA

Randomised, cluster-randomised and quasi-randomised controlled trials that assess the effects of aspirin, heparin (either low-molecular-weight heparin (LMWH) or unfractionated heparin (UFH]), or a combination of aspirin and heparin compared with no treatment, placebo or another, on pregnancy outcomes in women with persistent aPL and recurrent pregnancy loss were eligible. All treatment regimens were considered.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion criteria and risk of bias. Two review authors independently extracted data and checked them for accuracy and the certainty of the evidence was assessed using the GRADE approach.

MAIN RESULTS

Eleven studies (1672 women) met the inclusion criteria; nine randomised controlled trials and two quasi-RCTs. The studies were conducted in the USA, Canada, UK, China, New Zealand, Iraq and Egypt. One included trial involved 1015 women, all other included trials had considerably lower numbers of participants (i.e. 141 women or fewer). Some studies had high risk of selection and attrition bias, and many did not include sufficient information to judge the risk of reporting bias. Overall, the certainty of evidence is low to very low due to the small numbers of women in the studies and to the risk of bias. The dose and type of heparin and aspirin varied among studies. One study compared aspirin alone with placebo; no studies compared heparin alone with placebo and there were no trials that had a no treatment comparator arm during pregnancy; five studies explored the efficacy of heparin (either UFH or LMWH) combined with aspirin compared with aspirin alone; one trial compared LMWH with aspirin; two trials compared the combination of LMWH plus aspirin with the combination of UFH plus aspirin; two studies evaluated the combination of different doses of heparin combined with aspirin. All trials used aspirin at a low dose. Aspirin versus placebo We are very uncertain if aspirin has any effect on live birth compared to placebo (risk ratio (RR) 0.94, 95% confidence interval (CI) 0.71 to 1.25, 1 trial, 40 women, very low-certainty evidence). We are very uncertain if aspirin has any effect on the risk of pre-eclampsia, pregnancy loss, preterm delivery of a live infant, intrauterine growth restriction or adverse events in the child, compared to placebo. We are very uncertain if aspirin has any effect on adverse events (bleeding) in the mother compared with placebo (RR 1.29, 95% CI 0.60 to 2.77, 1 study, 40 women). The certainty of evidence for these outcomes is very low because of imprecision, due to the low numbers of women involved and the wide 95% CIs, and also because of risk of bias. Venous thromboembolism and arterial thromboembolism were not reported in the included studies. Heparin plus aspirin versus aspirin alone Heparin plus aspirin may increase the number of live births (RR 1.27, 95% CI 1.09 to 1.49, 5 studies, 1295 women, low-certainty evidence). We are uncertain if heparin plus aspirin has any effect on the risk of pre-eclampsia, preterm delivery of a live infant, or intrauterine growth restriction, compared with aspirin alone because of risk of bias and imprecision due to the low numbers of women involved and the wide 95% CIs. We are very uncertain if heparin plus aspirin has any effect on adverse events (bleeding) in the mother compared with aspirin alone (RR 1.65, 95% CI 0.19 to 14.03, 1 study, 31 women). No women in either the heparin plus aspirin group or the aspirin alone group had heparin-induced thrombocytopenia, allergic reactions, or venous or arterial thromboembolism. Similarly, no infants had congenital malformations. Heparin plus aspirin may reduce the risk of pregnancy loss (RR 0.48, 95% CI 0.32 to 0.71, 5 studies, 1295 women, low-certainty evidence). When comparing LMWH plus aspirin versus aspirin alone the pooled RR for live birth was 1.20 (95% CI 1.04 to 1.38, 3 trials, 1155 women). In the comparison of UFH plus aspirin versus aspirin alone, the RR for live birth was 1.74 (95% CI 1.28 to 2.35, 2 trials, 140 women).

AUTHORS' CONCLUSIONS

The combination of heparin (UFH or LMWH) plus aspirin during the course of pregnancy may increase live birth rate in women with persistent aPL when compared with aspirin treatment alone. The observed beneficial effect of heparin was driven by one large study in which LMWH plus aspirin was compared with aspirin alone. Adverse events were frequently not, or not uniformly, reported in the included studies. More research is needed in this area in order to further evaluate potential risks and benefits of this treatment strategy, especially among women with aPL and recurrent pregnancy loss, to gain consensus on the ideal prevention for recurrent pregnancy loss, based on a risk profile.

Association between blood lipid level and embryo quality during in vitro fertilization

The aim of this study was to investigate the relationship between blood lipid level and the parameters of embryo morphology of in vitro fertilization (IVF).A total of 488 patients undergoing conventional IVF were divided into pregnant (n = 286) and nonpregnant (n = 202) groups. Levels of triglycerides (TG), total cholesterol (TC), high-density lipoproteins (HDL), low-density lipoprotein (LDL), lipoprotein (a), lipoprotein (b), and embryo outcomes were studied. Spearman correlation was performed to analyze the correlation between blood lipid levels and embryo quality in pregnant group.The normal fertilization rate and number of good quality embryos were higher than nonpregnant group (P < .05). TG, TC, and LDL levels were negatively correlated with number of normal fertilized oocytes, while TG, TC, and Lp(b) were negatively correlated with number of good quality embryos. TG level was negatively correlated with number of oocytes and cleavage embryos while HDL and Lp(a) were positively correlated with number of oocytes, normal fertilized oocytes and cleavage embryos (P < .05).TG, TC, LDL, and Lp(b) levels had negative correlation with embryo quality, while HDL and Lp(a) had positive correlation with the embryo quality. Our present findings showed blood lipid levels may provide certain reference for the prediction of IVF pregnancy outcome.

Gestational hypercholesterolemia alters fetal hepatic lipid metabolism and microRNA expression in Apo-E-deficient mice

Maternal hypercholesterolemia (MHC) is a pathological condition characterized by an exaggerated rise in maternal serum cholesterol during gestation, which can alter offspring hepatic lipid metabolism. However, the extent that these maladaptations occur during gestation and the molecular mechanisms involved remain unknown. MicoRNAs (miRNA) are small, noncoding RNAs that contribute to the development and progression of nonalcoholic fatty liver disease. Therefore, we sought to determine the degree to which in utero exposure to excessive cholesterol affects fetal hepatic lipid metabolism and miRNA expression. Twelve female apoE^-/- mice were randomly assigned to two different chow-based diets throughout gestation: control (CON) or the CON diet with cholesterol (0.15%). MHC reduced maternal fecundity and reduced litter size and weight. On gestational day 18, fetuses from MHC dams possessed increased placental cholesterol and hepatic triglycerides (TG), which were accompanied by a downregulation in the expression of hepatic lipogenic and TG synthesis and transport genes. Furthermore, fetal livers from MHC mothers showed increased miRNA-27a and reduced miRNA-200c expression. In summary, in utero exposure to MHC alters fetal lipid metabolism and lends mechanistic insight that implicates early changes in miRNA expression that may link to later-life programming of disease risk.

Antiplatelet agents for preventing pre-eclampsia and its complications

BACKGROUND

Pre-eclampsia is associated with deficient intravascular production of prostacyclin, a vasodilator, and excessive production of thromboxane, a vasoconstrictor and stimulant of platelet aggregation. These observations led to the hypotheses that antiplatelet agents, low-dose aspirin in particular, might prevent or delay development of pre-eclampsia.

OBJECTIVES

To assess the effectiveness and safety of antiplatelet agents, such as aspirin and dipyridamole, when given to women at risk of developing pre-eclampsia.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (30 March 2018), and reference lists of retrieved studies. We updated the search in September 2019 and added the results to the awaiting classification section of the review.

SELECTION CRITERIA

All randomised trials comparing antiplatelet agents with either placebo or no antiplatelet agent were included. Studies only published in abstract format were eligible for inclusion if sufficient information was available. We would have included cluster-randomised trials in the analyses along with individually-randomised trials, if any had been identified in our search strategy. Quasi-random studies were excluded. Participants were pregnant women at risk of developing pre-eclampsia. Interventions were administration of an antiplatelet agent (such as low-dose aspirin or dipyridamole), comparisons were either placebo or no antiplatelet.

DATA COLLECTION AND ANALYSIS

Two review authors assessed trials for inclusion and extracted data independently. For binary outcomes, we calculated risk ratio (RR) and its 95% confidence interval (CI), on an intention-to-treat basis. For this update we incorporated individual participant data (IPD) from trials with this available, alongside aggregate data (AD) from trials where it was not, in order to enable reliable subgroup analyses and inclusion of two key new outcomes. We assessed risk of bias for included studies and created a 'Summary of findings' table using GRADE.

MAIN RESULTS

Seventy-seven trials (40,249 women, and their babies) were included, although three trials (relating to 233 women) did not contribute data to the meta-analysis. Nine of the trials contributing data were large (> 1000 women recruited), accounting for 80% of women recruited. Although the trials took place in a wide range of countries, all of the nine large trials involved only women in high-income and/or upper middle-income countries. IPD were available for 36 trials (34,514 women), including all but one of the large trials. Low-dose aspirin alone was the intervention in all the large trials, and most trials overall. Dose in the large trials was 50 mg (1 trial, 1106 women), 60 mg (5 trials, 22,322 women), 75mg (1 trial, 3697 women) 100 mg (1 trial, 3294 women) and 150 mg (1 trial, 1776 women). Most studies were either low risk of bias or unclear risk of bias; and the large trials were all low risk of bas. Antiplatelet agents versus placebo/no treatment The use of antiplatelet agents reduced the risk of proteinuric pre-eclampsia by 18% (36,716 women, 60 trials, RR 0.82, 95% CI 0.77 to 0.88; high-quality evidence), number needed to treat for one women to benefit (NNTB) 61 (95% CI 45 to 92). There was a small (9%) reduction in the RR for preterm birth <37 weeks (35,212 women, 47 trials; RR 0.91, 95% CI 0.87 to 0.95, high-quality evidence), NNTB 61 (95% CI 42 to 114), and a 14% reduction infetal deaths, neonatal deaths or death before hospital discharge (35,391 babies, 52 trials; RR 0.85, 95% CI 0.76 to 0.95; high-quality evidence), NNTB 197 (95% CI 115 to 681). Antiplatelet agents slightly reduced the risk of small-for-gestational age babies (35,761 babies, 50 trials; RR 0.84, 95% CI 0.76 to 0.92; high-quality evidence), NNTB 146 (95% CI 90 to 386), and pregnancies with serious adverse outcome (a composite outcome including maternal death, baby death, pre-eclampsia, small-for-gestational age, and preterm birth) (RR 0.90, 95% CI 0.85 to 0.96; 17,382 women; 13 trials, high-quality evidence), NNTB 54 (95% CI 34 to 132). Antiplatelet agents probably slightly increase postpartum haemorrhage > 500 mL (23,769 women, 19 trials; RR 1.06, 95% CI 1.00 to 1.12; moderate-quality evidence due to clinical heterogeneity), and they probably marginally increase the risk of placental abruption, although for this outcome the evidence was downgraded due to a wide confidence interval including the possibility of no effect (30,775 women; 29 trials; RR 1.21, 95% CI 0.95 to 1.54; moderate-quality evidence). Data from two large trials which assessed children at aged 18 months (including results from over 5000 children), did not identify clear differences in development between the two groups.

AUTHORS' CONCLUSIONS

Administering low-dose aspirin to pregnant women led to small-to-moderate benefits, including reductions in pre-eclampsia (16 fewer per 1000 women treated), preterm birth (16 fewer per 1000 treated), the baby being born small-for-gestational age (seven fewer per 1000 treated) and fetal or neonatal death (five fewer per 1000 treated). Overall, administering antiplatelet agents to 1000 women led to 20 fewer pregnancies with serious adverse outcomes. The quality of evidence for all these outcomes was high. Aspirin probably slightly increased the risk of postpartum haemorrhage of more than 500 mL, however, the quality of evidence for this outcome was downgraded to moderate, due to concerns of clinical heterogeneity in measurements of blood loss. Antiplatelet agents probably marginally increase placental abruption, but the quality of the evidence was downgraded to moderate due to low event numbers and thus wide 95% CI. Overall, antiplatelet agents improved outcomes, and at these doses appear to be safe. Identifying women who are most likely to respond to low-dose aspirin would improve targeting of treatment. As almost all the women in this review were recruited to the trials after 12 weeks' gestation, it is unclear whether starting treatment before 12 weeks' would have additional benefits without any increase in adverse effects. While there was some indication that higher doses of aspirin would be more effective, further studies would be warranted to examine this.

Lipid levels after childbirth and association with number of children: A population-based cohort study

OBJECTIVE

Low parity women are at increased risk of cardiovascular mortality. Unfavourable lipid profiles have been found in one-child mothers years before they conceive. However, it remains unclear whether unfavourable lipid profiles are evident in these women also after their first birth. The aim was to estimate post-pregnancy lipid levels in one-child mothers compared to mothers with two or more children and to assess these lipid's associations with number of children.

METHODS

We used data on 32 618 parous women (4 490 one-child mothers and 28 128 women with ≥2 children) examined after first childbirth as part of Cohort of Norway (1994-2003) with linked data on reproduction and number of children from the Medical Birth Registry of Norway (1967-2008). Odds ratios (ORs) with 95% confidence intervals (CIs) for one lifetime pregnancy (vs. ≥2 pregnancies) by lipid quintiles were obtained by logistic regression and adjusted for age at examination, year of first birth, body mass index, oral contraceptive use, smoking and educational level.

RESULTS

Compared to women with the lowest quintiles, ORs for one lifetime pregnancy for the highest quintiles of LDL and total cholesterol were 1.30 (95%CI: 1.14-1.45) and 1.43 (95%CI: 1.27-1.61), respectively. Sensitivity analysis (women <40 years) showed no appreciable change in our results. In stratified analyses, estimates were slightly stronger in overweight/obese, physically inactive and women with self-perceived bad health.

CONCLUSIONS

Mean lipid levels measured after childbirth in women with one child were significantly higher compared to mothers with two or more children and were associated with higher probability of having only one child. These findings corroborate an association between serum lipid levels and one lifetime pregnancy (as a feature of subfecundity), emphasizing that these particular women may be a specific predetermined risk group for cardiovascular related disease and death.

Pilot randomized trial of short-term changes in inflammation and lipid levels during and after aspirin and pravastatin therapy

BACKGROUND

Inflammation and elevated blood lipids are associated with infertility. Aspirin and statin therapy may improve infertility treatment outcomes among overweight and obese women with systemic inflammation, but little is known about the short-term effects of statins in this population. We conducted a pilot study of aspirin, pravastatin, or combined treatment among a group of overweight and obese, reproductive-aged women. Our goal was to characterize short-term changes in inflammatory and lipid biomarkers during and after treatment.

METHODS

In this open-label trial, women aged 18-40 years with a body mass index ≥25 kg/m² were randomized to receive either 162 mg aspirin, 40 mg pravastatin, or both. The study medication was taken daily for 2 weeks, and participants were then followed for a two-week washout period. Participants provided blood samples at baseline, after the intervention period, and after the washout period. The outcomes were changes in biomarkers of inflammation and lipids measured in blood components at each timepoint.

RESULTS

Nine, 8, and 8 women were randomized to the aspirin, pravastatin, and combined arms, respectively. Analyses were conducted among 8, 7, and 7 women in the aspirin, pravastatin, and combined arms for whom biomarker data was available at baseline. High-sensitivity C-reactive protein (hsCRP) levels were lower after treatment in all arms and continued to decrease after washout in the pravastatin and combined arms. Results were consistent between the whole sample and women with baseline hsCRP between 2 and 10 mg/L. Low-density lipoprotein (LDL) cholesterol was lower after treatment in the pravastatin and combined arms and rose slightly after washout.

CONCLUSIONS

Our results provide preliminary evidence that short-term aspirin and pravastatin therapy reduces hsCRP and LDL cholesterol among overweight and obese women of reproductive age, including those with low-grade inflammation. Because of these short-term effects, these drugs may improve infertility treatment outcomes in this population, which we will assess in a future randomized trial.

Preconception serum lipids and lipophilic micronutrient levels are associated with live birth rates after IVF

RESEARCH QUESTION

Is a mixture of preconception serum lipids and lipophilic micronutrients associated with clinical pregnancy and live births?

DESIGN

In this prospective cohort study, blood serum was collected on the day of oocyte retrieval for 180 women undergoing IVF at an academic reproductive health centre. Concentrations of lipids (phospholipids, total cholesterol, high- and low-density lipoproteins, and triglycerides) and lipophilic micronutrients (α-, δ-, and γ-tocopherols, retinol, β- and α-carotenes, β-cryptoxanthin, lutein and lycopene) were determined using diagnostic reagent kits and high-performance liquid chromatography. Poisson regression was used with robust variance estimation to evaluate changes in Z-scores for the mixture of serum lipid and lipophilic micronutrient concentrations as predictors of embryo implantation, clinical pregnancy and live birth, adjusted for age, body mass index (BMI), race, smoking status, infertility diagnosis, ovarian stimulation protocol and other measured lipid and lipophilic micronutrient concentrations.

RESULTS

Each SD higher serum triglyceride concentration was associated with a lower chance of live birth (RR 0.54; 95% CI 0.33 to 0.90) whereas a 1 SD higher serum α-tocopherol concentration, as part of a mixture of serum lipids and lipophilic micronutrients, was associated with a higher likelihood for a live birth (RR 1.61; 95% CI 1.11 to 2.36). Serum β-carotene concentrations were associated with live birth in a non-linear fashion; low β-carotene was associated with a lower chance of live birth and high β-carotene with a higher chance of live birth.

CONCLUSION

Although components of a mixture of lipids and lipophilic micronutrients were associated with live birth outcomes after IVF, a larger investigation is necessary to fully evaluate the potential clinical implications.

Metabolic syndrome and time to pregnancy: a retrospective study of nulliparous women

OBJECTIVE

To determine: (1) the association between metabolic syndrome (MetS), time to pregnancy (TTP), and infertility; (2) associations between individual and an increasing number of MetS components, TTP, and infertility; and (3) whether these relationships differ by body mass index (BMI < 30 kg/m² versus BMI ≥ 30 kg/m² ).

DESIGN

Retrospective cohort study.

SETTING

Multiple centres (in Australia, Ireland, New Zealand, and the UK).

POPULATION

Five thousand five hundred and nineteen low-risk nulliparous pregnant women.

METHODS

Data on retrospectively reported TTP (number of months to conceive) and a blood sample to assess metabolic health were collected between 14 and 16 weeks of gestation. MetS was defined according to the International Diabetes Federation criteria. Accelerated failure time models with log-normal distribution were conducted to estimate time ratios (TRs) and 95% CIs. Differences in MetS on infertility (TTP > 12 months) were compared using a generalised linear model (Poisson distribution) with robust variance estimates (relative risks, RRs; 95% CIs). All analyses (entire cohort and split by BMI) were controlled for a range of maternal and paternal confounding factors.

MAIN OUTCOME MEASURES

Time to pregnancy and infertility.

RESULTS

Of the 5519 women included, 12.4% (n = 684) had MetS. Compared with women without MetS, women with MetS had a longer TTP (adjusted TR 1.30; 95% CI 1.15-1.46), which was similar in women who were obese and in women who were not obese. Marginal estimates for median TTP in women with MetS versus without MetS was 3.1 months (3.0-3.3 months) versus 4.1 months (3.6-4.5 months), respectively. Women with MetS were at a 62% greater risk for infertility and were at a greater risk for infertility whether they were obese (adjusted RR 1.62; 95% CI 1.15-2.29) or not (adjusted RR 1.73; 95% CI 1.33-2.23). Reduced high-density lipoprotein cholesterol (HDL-C) and raised triglycerides (TGs) were the main individual components associated with risk for infertility.

CONCLUSION

Metabolic syndrome is associated with longer TTP and infertility, independent of obesity. Additional studies, before pregnancy, are required to support our findings and to determine the applicability of which combinations of metabolic abnormalities pose the greatest risk to delayed fertility, or whether individual components are amenable to modification.

TWEETABLE ABSTRACT

Metabolic syndrome is associated with longer time to pregnancy and infertility, independent of obesity.

Childhood cardiovascular health and subfertility: the Bogalusa Heart Study

BACKGROUND

Although childhood cardiovascular risk can contribute to adult cardiovascular disease, and fertility and adult cardiovascular health are linked, the association between early-life cardiovascular risk and female infertility has not been studied.

METHODS

A total of 1799 women participated in the Babies substudy of the Bogalusa Heart Study. Systolic blood pressure (SBP), diastolic blood pressure (DBP), low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides, glucose, and insulin were age-standardized and examined as predictors of self-reported fertility difficulties using multivariable logistic regression with adjustment for confounders. Polycystic ovarian syndrome (PCOS) was assessed via a report of diagnosis and symptoms, using a validated questionnaire.

RESULTS

Women with a history of PCOS were more likely to report fertility difficulties. Childhood and adolescent cardiovascular risk factors were generally not associated with fertility indicators, although childhood LDL (aOR 1.38 per one-SD increase, 0.97-1.96) and total cholesterol (aOR 1.49, 1.06-2.11) were raised in those who never became pregnant. Pre-pregnancy risk SBP (overall fertility, aOR 1.49, 1.00-2.23) and glucose levels (ever tried but unable, aOR 2.65, 1.39-5.06) were associated with an increased risk of some infertility indicators. These results were largely unaffected by exclusion of women with PCOS.

CONCLUSION

Some childhood and pre-pregnancy cardiovascular risk factors are associated with adult subfertility.

Women's prepregnancy lipid levels and number of children: a Norwegian prospective population-based cohort study

OBJECTIVE

To study prepregnancy serum lipid levels and the association with the number of children.

DESIGN

Prospective, population-based cohort.

SETTING

Linked data from the Cohort of Norway and the Medical Birth Registry of Norway.

PARTICIPANTS

2645 women giving birth to their first child during 1994-2003 (488 one-child mothers and 2157 women with ≥2 births) and 1677 nulliparous women.

MAIN OUTCOME MEASURES

ORs for no and one lifetime pregnancy (relative to ≥2 pregnancies) obtained by multinomial logistic regression, adjusted for age at examination, education, body mass index (BMI), smoking, time since last meal and oral contraceptive use.

RESULTS

Assessed in quintiles, higher prepregnant triglyceride (TG) and TG to high-density lipoprotein (TG:HDL-c) ratio levels were associated with increased risk of one lifetime pregnancy compared with having ≥2 children. Compared with the highest quintile, women in the lowest quintile of HDL cholesterol levels had an increased risk of one lifetime pregnancy (OR 1.7, 95% CI 1.2 to 2.4), as were women with the highest low-density lipoprotein (LDL) cholesterol, TG and TG:HDL-c ratio quintiles (compared with the lowest) (OR 1.2, 95% CI 0.8 to 1.7; OR 2.2, 95% CI 1.5 to 3.2; and OR 2.2, 95% CI 1.5 to 3.2, respectively). Similar effects were found in women with BMI≥25 and the highest LDL and total cholesterol levels in risk of lifetime nulliparity.

CONCLUSION

Women with unfavourable prepregnant lipid profile had higher risk of having no or only one child. These findings substantiate an association between prepregnant serum lipid levels and number of children. Previously observed associations between low parity and increased cardiovascular mortality may in part be due to pre-existing cardiovascular disease lipid risk factors.