Uncovering the link between reproductive factors and multiple sclerosis: A case-control study on Iranian females

Evaluation of ovarian reserve and the assisted reproductive technology (ART) cycles' outcome as well as the relapse rate within one year after ART in women with multiple sclerosis: a case-control study

OBJECTIVE

To compare the ovarian reserve and the results of infertility treatment, as well as to investigate the relapse rate in the first year after the assisted reproductive technology (ART) cycle in patients with multiple sclerosis (MS) referred to Royan Institute.

MATERIALS AND METHODS

This retrospective study was carried out to evaluate all women diagnosed with MS and referred to Royan Institute for assessment and treatment of possible infertility between 2011 and 2022. The control group consisted of randomly selected healthy women with tubal factor infertility who were referred for treatment during the same time period and matched in terms of age. A comparison was made between groups in terms of ovarian reserve and infertility treatment outcomes. Additionally, patients with MS who met the criteria were monitored via telephone to evaluate the symptoms, disability and relapse rate both pre- and post-ART.

RESULTS

Over the course of a decade, the database documented a total of 60 cases diagnosed with MS. Upon examination of the records, it was found that in 27 patients only admission was done without any hormonal assessment or infertility treatment cycle and 5 patients proceeded with the intrauterine insemination cycle. Eventually, 28 women with MS underwent the ART cycle and all of them were treated with interferon beta, glatiramer acetate, or some oral disease modifying therapies. No statistically significant difference in terms of the basal levels of luteinizing hormone, follicle-stimulating hormone and anti-Müllerian hormone was found between the MS and control groups (P > 0.05). Two groups were comparable in terms of menstrual status. The study revealed that both groups exhibited similarities in terms of the controlled ovarian stimulation protocol and duration, the dosage of gonadotropin administered, as well as the ovarian response type, clinical pregnancy rate, and live birth rate (P > 0.05). After follow up, only 2 patients (9.5%) reported relapse of symptoms within one year after ART.

CONCLUSION

The ovarian reserve and ovarian stimulation cycle and pregnancy outcomes following the ART cycle in MS patients were similar to the age-matched control group. The relapse rate of multiple sclerosis did not show a significant increase within a year following the ART cycle.

Multiple sclerosis and pregnancy: Pathogenesis, influencing factors, and treatment options

Multiple sclerosis (MS) is an autoimmune-mediated degenerative disease of the central nervous system, characterized by inflammatory demyelination. It is primarily found in women of childbearing age, making pregnancy a significant concern for both patients with MS and clinicians. To assist these patients in achieving their desire for pregnancy, reducing MS relapses during all stages of pregnancy, preventing the progression of MS, mitigating the impact of MS treatment on the course and outcome of pregnancy, and a thorough understanding of the relationship between pregnancy and MS, as well as specific management and the application of relevant medications for MS patients at each stage of pregnancy, are essential. This article provides an update on pregnancy-related issues in women with MS, including the general recommendations for management at each stage of pregnancy.

Association of pregnancies with risk of multiple sclerosis

Background:

Pregnancies have an impact on the disease course of multiple sclerosis (MS), but their relationship with MS risk is yet unclear.

Objective:

To determine the relationships of pregnancies and gynecological diagnoses with MS risk.

Methods:

In this retrospective case–control study, we assessed differences in gynecological International Classification of Diseases, 10th Revision (ICD-10) code recording rates between women with MS (n = 5720), Crohn’s disease (n = 6280), or psoriasis (n = 40,555) and women without these autoimmune diseases (n = 26,729) in the 5 years before diagnosis.

Results:

Twenty-eight ICD-10 codes were recorded less frequently for women with MS as compared to women without autoimmune disease, 18 of which are pregnancy-related. After adjustment for pregnancies, all codes unrelated to pregnancies were still negatively associated with MS. In a sensitivity analysis excluding women with evidence for possible demyelinating events before diagnosis, all associations were more pronounced. In comparison to women with psoriasis, most associations could be confirmed; that was not true in comparison to women with Crohn’s disease.

Conclusion:

Our findings provide evidence for a possible protective effect of pregnancies on MS risk likely independent of or in addition to a previously suggested reversed causality. The negative associations of gynecological disorders with disease risk need further investigation. The associations might be shared by different autoimmune diseases.

Effect of puberty on the immune system: Relevance to multiple sclerosis

Puberty is a dynamic period marked by changing levels of sex hormones, the development of secondary sexual characteristics and reproductive maturity. This period has profound effects on various organ systems, including the immune system. The critical changes that occur in the immune system during pubertal onset have been shown to have implications for autoimmune conditions, including Multiple Sclerosis (MS). MS is rare prior to puberty but can manifest in children after puberty. This disease also has a clear female preponderance that only arises following pubertal onset, highlighting a potential role for sex hormones in autoimmunity. Early onset of puberty has also been shown to be a risk factor for MS. The purpose of this review is to overview the evidence that puberty regulates MS susceptibility and disease activity. Given that there is a paucity of studies that directly evaluate the effects of puberty on the immune system, we also discuss how the immune system is different in children and mice of pre- vs. post-pubertal ages and describe how gonadal hormones may regulate these immune mechanisms. We present evidence that puberty enhances the expression of co-stimulatory molecules and cytokine production by type 2 dendritic cells (DC2s) and plasmacytoid dendritic cells (pDCs), increases T helper 1 (Th1), Th17, and T follicular helper immunity, and promotes immunoglobulin (Ig)G antibody production. Overall, this review highlights how the immune system undergoes a functional maturation during puberty, which has the potential to explain the higher prevalence of MS and other autoimmune diseases seen in adolescence.

Association of Pregnancy With the Onset of Clinically Isolated Syndrome

Importance

Multiple sclerosis (MS) is usually diagnosed in women during their childbearing years. Currently, no consensus exists on whether pregnancy can delay the first episode of demyelination or clinically isolated syndrome (CIS).

Objective

To investigate the association of pregnancy with time to CIS onset.

Design, Setting, and Participants

This multicenter cohort study collected reproductive history (duration of each pregnancy, date of delivery, length of breastfeeding) on all participants between September 1, 2016, and June 25, 2019. Adult women being treated at the MS outpatient clinics of 4 tertiary hospitals in 2 countries (Charles University and General University Hospital in Prague, Czech Republic; Royal Melbourne Hospital in Melbourne, Australia; Alfred Hospital in Melbourne, Australia; and John Hunter Hospital in Newcastle, Australia) were recruited to participate in the study. Preexisting data (date of CIS onset, date of birth, sex, date of clinical onset, and Expanded Disability Status Scale result) were collected from MSBase, an international registry of long-term prospectively collected data on patients with MS. Data analyses were performed from June 1, 2019, to February 3, 2020.

Exposures

Gravida (defined as any pregnancy, including pregnancy that ended in miscarriage and induced abortion) and parity (defined as childbirth after gestational age of more than 20 weeks, including livebirth and stillbirth) before CIS onset.

Main Outcomes and Measures

Time to CIS onset. The following were assessed: (1) whether women with previous pregnancies and childbirths had a delayed onset of CIS compared with those who had never been pregnant and those who had never given birth, and (2) whether a dose response existed, whereby a higher number of gravidity and parity was associated with a later onset of CIS.

Results

Of the 2557 women included in the study, the mean (SD) age at CIS onset was 31.5 (9.7) years. Of these women, before CIS onset, 1188 (46%) had at least 1 pregnancy and 1100 (43%) had at least 1 childbirth. The mean (SD) age at first pregnancy was 23.3 (4.5) years and at first childbirth was 23.8 (4.5) years. Women with previous pregnancies and childbirths had a later onset of CIS compared with those who had never been pregnant (HR, 0.68; 95% CI, 0.62-0.75; P < .001), with a median delay of 3.3 (95% CI, 2.5-4.1) years. Women who had given birth also had a later CIS onset compared with women who had never given birth (HR 0.68; 95% CI, 0.61-0.75; P < .001), with a similar median delay of 3.4 (95% CI, 1.6-5.2) years. A higher gravidity and parity number was not associated with delay in CIS onset.

Conclusions and Relevance

This study suggests an association between previous pregnancies and childbirths and timing of CIS onset, but having more pregnancies or childbirths did not appear to be associated with a later CIS onset. Further studies are needed to help explain the mechanisms behind the associations between pregnancy and onset of multiple sclerosis.

Age at menarche and risk of multiple sclerosis (MS): a systematic review and meta-analysis

BACKGROUND

Some studies have looked at the age at menarche and risk of Multiple Sclerosis (MS).We aimed to conduct a systematic review and meta-analysis to estimate a pooled odds ratio of developing MS by increasing age at menarche.

METHODS

We searched PubMed, Scopus, EMBASE, CINAHL, Web of Science, Ovid, google scholar and gray literature (references of references, congress abstracts) up to 10th April 2019.

RESULTS

The literature search found 312 articles. After eliminating duplicates, reviews, case reports and trials, 18 articles remained. Three articles were ultimately included in the final analysis. Two studies were from Iran, and one from Canada. The pooled odds ratio (OR) for increasing 1 year of age at menarche was 0.88 (95% CI:0.82-0.94), with no significant heterogeneity (I2 = 49%, p = 0.1). Mean age at menarche was significantly different between case and control groups (mean difference = - 0.22, 95% CI = -0.42,-0.02).

CONCLUSION

The result of this systematic review showed that the risk of MS decreases by increasing age at menarche.

Pregnancy and autoimmune diseases

Autoimmune diseases (AID) are more prevalent in women than in men, and pregnancy-related factors such as hormonal modulation and fetal microchimerism may influence the future risk of maternal AID. For women with AID, optimizing reproductive health requires a continuum of multidisciplinary care that initiates well before the desire for pregnancy is articulated. Family planning is essential so that pregnancy can be timed when disease is stable and to allow for appropriate medication adjustments. When contraception is used, the choice of method needs to take into consideration underlying disease and laboratory features. For females undergoing gonadotoxic therapy, options for preserving ovarian health and fertility warrant consideration, even among those who are not contemplating future pregnancy. Both maternal and fetal outcomes are optimized with multispecialty care as well as close monitoring during pregnancy and the postpartum period and when treatment regimens compatible with pregnancy are maintained to control underlying disease activity.

Environmental and genetic risk factors for MS: an integrated review

Recent findings have provided a molecular basis for the combined contributions of multifaceted risk factors for the onset of multiple sclerosis (MS). MS appears to start as a chronic dysregulation of immune homeostasis resulting from complex interactions between genetic predispositions, infectious exposures, and factors that lead to pro-inflammatory states, including smoking, obesity, and low sun exposure. This is supported by the discovery of gene-environment (GxE) interactions and epigenetic alterations triggered by environmental exposures in individuals with particular genetic make-ups. It is notable that several of these pro-inflammatory factors have not emerged as strong prognostic indicators. Biological processes at play during the relapsing phase of the disease may result from initial inflammatory-mediated injury, while risk factors for the later phase of MS, which is weighted toward neurodegeneration, are not yet well defined. This integrated review of current evidence guides recommendations for clinical practice and highlights research gaps.

Pregnancy and multiple sclerosis: Clinical effects across the lifespan

Multiple sclerosis (MS) is commonly diagnosed in women of childbearing age. Having a greater understanding of the effects of pregnancy on the course of MS will lead to improved family-planning counselling for women. We found well-established evidence for a protective effect of pregnancy on relapse occurrence in historical cohorts. More recent studies suggest that the protective effect of pregnancy against relapse may be lost in those women with more active disease treated with high efficacy therapies. Furthermore, a strong body of evidence suggests that gravidity after diagnosis of MS does not lead to worse long-term outcomes. More contentious however, is whether pregnancy can delay a first episode of demyelination or a confirmed diagnosis of MS. This review provides a detailed analysis of the literature relating to the clinical effects of pregnancy on MS outcomes across a woman's reproductive lifespan.

Age at Menarche and Risk of Multiple Sclerosis: Current Progress From Epidemiological Investigations

Multiple sclerosis (MS) is a chronic autoimmune inflammatory disorder of the brain and spinal cord in which focal lymphocytic infiltration leads to the damage of myelin and axons. As a multi-factorial complex trait, both genetic background and environmental factors are involved in MS etiology. The disease is more prevalent among women, and an overall female-to-male sex ratio of around 3 is usually reported. The fact that the female preponderance is only apparent among patients with disease onset after age 12 points toward a role of puberty in MS. A key marker of female pubertal development is menarche, however, evidence from previous epidemiological investigations has been sparse and conflicting: although some studies have linked earlier age at menarche (AAM) to an increased risk of MS, others have found no association or an inverse association. Understanding the effect of AAM in MS could increase our knowledge to the disease etiology, as well as deliver meaningful implication to patients' care by aiding clinical diagnosis. Therefore, we reviewed all the currently available epidemiological studies conducted for AAM and risk of MS in adult human populations. We found evidence supporting a possible favorable role of late AAM on MS risk, but this should be further confirmed by well-designed large-scale epidemiological studies and meta-analysis. Future work may be focused on Mendelian randomization analysis incorporating genetic markers to provide additional evidence of a putative causal relationship between AAM and MS. More work should be conducted for non-European populations to increase generalizability, and among the males to complementary with results from females. Future work may also be conducted focusing on hormonal reproductive factors other than menarche, and their effects in MS prognosis, severity, and drug response.