The effect of adding L-Carnitine to the GnRH-antagonist protocol on assisted reproductive technology outcome in women with polycystic ovarian syndrome: a randomized clinical trial

Astaxanthin compound nutrient improved insulin resistance, hormone levels, embryo quality and pregnancy outcomes in polycystic ovary syndrome patients undergoing in vitro fertilization/intracytoplasmic sperm injection

This study aimed to evaluate the effect of astaxanthin compound nutrient (ACN) complementary therapy on pregnancy outcomes in polycystic ovary syndrome (PCOS) patients undergoing in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI). This study enrolled 92 patients with PCOS who were continuously supplemented with ACN for three months prior to IVF/ICSI treatment from 2021 to 2023, and selected 92 patients who did not receive the treatment during the same period as controls. Baseline characteristics, ovulation induction outcomes, and pregnancy outcomes were compared between the two groups. In addition, the body mass index (BMI), anti-Müllerian hormone (AMH), antral follicle counting (AFC), fasting blood glucose (FBG), fasting insulin (FINS), homeostasis model assessment of insulin resistant (HOME-IR), and basal sex hormones of the supplementary group patients before and after treatment were compared. The results showed that there were no significant differences in the patient's duration of stimulation, total gonadotropin dose, peak E2 levels, and number of retrieved oocytes between the two groups. However, the number of 2 pronucleus (PN) fertilization, transferable embryos, and high-quality embryos was significantly higher in the ACN group compared with the control group. For both fresh and frozen embryo transplantation, positive pregnancy outcomes increased in PCOS patients who received supplementation of ACN for 3 months. In addition, after 3 months of supplementing with ACN, the patient's BMI, AMH, fasting insulin, HOME-IR, basal luteinising hormone (bLH), and basal testosterone (bT) decreased compared to before treatment. This study suggested that ACN improved insulin resistance, hormone levels, embryo quality and pregnancy outcomes in PCOS patients.

The efficacy of orally administered L-carnitine in alleviating ovarian dysfunctions has laid the foundation for targeted in vivo use: a study employing self-control and propensity score matching

Objective

This study aimed to evaluate the effectiveness of oral L-carnitine administration in patients after treatment failure to lay the groundwork for targeted in vivo use.

Methods and materials

A total of 515 In Vitro Fertilization (IVF) patients undergoing subsequent cycles were included after applying exclusion criteria. They were divided into a control group of 362 patients and a study group of 153 patients who received oral L-carnitine until oocyte retrieval.140 patients were matched according to maternal age, infertility duration, body mass index (BMI), day three top-quality embryos rate, by propensity score matching (PSM). The study investigated the relationship between L-carnitine treatment and in vivo oocyte maturation, normal fertilization, and subsequent embryo development.

Results

Following PSM, initial differences in BMI and Day3 top-quality embryo rate between groups were nullified, we created two comparable cohorts with highly similar characteristics. In the subsequent cycles, the study group showed significant improvements in in vivo oocyte maturation rate at retrieval (p=0.002), normal in vitro fertilization rate (p=0.003), blastocyst formation rate (p=0.003), and usable blastocyst rate compared to controls. Although there was no significant difference in the top-quality embryo rate on Day 3, the study group showed a 10% increase in the upper quartile (55.35% vs. 66.67%). The cumulative clinical pregnancy and live birth rates showed a significant improvement (59.82% vs. 68.42%,p=0.004, 47.41% vs. 59.80%, p=0.002). Furthermore, self-control analysis revealed substantial enhancements (p<0.001) in all outcome measures following L-carnitine administration, resulting in the birth of 74 healthy neonates without congenital anomalies.

Conclusion

We theorized that daily oral intake of L-carnitine before oocyte retrieval could boost oocyte quality and embryonic development, thus improving IVF outcomes. Ongoing investigations hold the potential to offer valuable insights into the applications and mechanisms underlying the therapeutic effectiveness of L-carnitine.

Nutritional supplements and IVF: an evidence-based approach

Many women undergoing IVF take supplements during treatment. The purpose of this review was to systematically review these nutritional supplements. The therapies studied are dehydroepiandrosterone (DHEA), melatonin, co-enzyme Q10 (CoQ1O), carnitine, selenium, vitamin D, myo-inositol, omega-3, Chinese herbs and dietary interventions. A literature search up to May 2023 was undertaken. The data suggest that a simple nutritional approach would be to adopt a Mediterranean diet. With regards to supplements to treat a potential poor ovarian response to ovarian stimulation, starting DHEA and COQ-10 before cycle commencement is better than control therapies. Furthermore, medication with CoQ10 may have some merit, although it is unclear whether its place is for older women, for those with a poor response to ovarian stimulation or for poor embryonic development. There appears a benefit for some IVF outcomes for the use of melatonin, although it is unclear what group of patients would derive the benefit and the appropriate dosing regimen. For women with polycystic ovary syndrome, there may be a benefit to the use of myo-inositol, although again the dosing regimen is unclear. Furthermore, the place of vitamin D supplementation has yet to be clarified, and supplementation with omega-3 free fatty acids may lead to improvements in clinical and embryological IVF outcomes.

Effects of L-carnitine supplementation for women with polycystic ovary syndrome: a systematic review and meta-analysis

Background

Polycystic ovary syndrome (PCOS) is a disorder in reproductive age women and is characterized by hyperandrogenic anovulation and oligo-amenorrhea, which leads to infertility. Anovulation in PCOS is associated with low follicle-stimulating hormone levels and the arrest of antral follicle development in the final stages of maturation. L-carnitine (LC) plays a role in fatty acid metabolism, which is found to be lacking in PCOS patients. This systematic review and meta-analysis aimed to determine the effectiveness of LC supplementation for patients with PCOS.

Methods

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Psychological Information Database (PsycINFO), and the World Health Organization International Clinical Trials Registry Platform for all randomized control trials, comparing LC alone or in combination with other standard treatments for the treatment of PCOS from inception till June 2021. We independently screened titles and abstracts to identify available trials, and complete texts of the trials were checked for eligibility. Data on the methods, interventions, outcomes, and risk of bias from the included trials were independently extracted by the authors. The estimation of risk ratios and mean differences with a 95 percent confidence interval (CI) was performed using a random-effects model.

Results

Nine studies with 995 participants were included in this review. Five comparison groups were involved. In one comparison group, LC reduced the fasting plasma glucose (FPG) (mean differences (MD) -5.10, 95% CI [-6.25 to -3.95]; P = 0.00001), serum low-density lipoprotein (LDL) (MD -25.00, 95% CI [-27.93 to -22.07]; P = 0.00001), serum total cholesterol (MD -21.00, 95% CI [-24.14 to -17.86]; P = 0.00001), and serum triglyceride (TG) (MD -9.00, 95% CI [-11.46 to -6.54]; P = 0.00001) with moderate certainty of evidence. Another comparison group demonstrated that LC lowers the LDL (MD -12.00, 95% CI [-15.80 to -8.20]; P = 0.00001), serum total cholesterol (MD -24.00, 95% CI [-27.61 to -20.39]; P = 0.00001), and serum TG (MD -19.00, 95% CI [-22.79 to -15.21]; P = 0.00001) with moderate certainty of evidence.

Conclusion

There was low to moderate certainty of evidence that LC improves Body Mass Index (BMI) and serum LDL, TG, and total cholesterol levels in women with PCOS.

Biological roles of l-carnitine in oocyte and early embryo development

Poor oocyte quality is responsible for female infertility. Multiple studies have been carried out to find supplements to enhance oocyte quality and mitigate infertility problems. l-carnitine and its derivatives have diverse roles in developing oocytes and early embryos. This review focuses on the in vitro and in vivo studies that using l-carnitine alone or in combination with other supplements for oocyte quality enhancement. The key roles of l-carnitine in oocyte quality and embryo growth were summarized, and the underlying mechanism was also elucidated. l-carnitine helps in the lipid metabolism process by controlling the transfer of fatty acids to mitochondria for β-oxidation. l-carnitine modulates glucose metabolism and enhances respiratory chain enzyme activity. Furthermore, it acts as an antioxidant to prevent oxidative damage and inhibit apoptosis, a signal in response to oxidative stress. Results show the potential of l-carnitine as a potential agent in assisted reproductive technology to improve oocyte quality and the subsequent embryonic development.