Lower follicular n-3 polyunsaturated fatty acid levels are associated with a better response to ovarian stimulation

Abstract

Objectives To analyze in detail the fatty acid (FA) composition of follicular fluid (FF) from two-sized follicles at oocyte retrieval and to determine associations of the FAs from large follicles with the woman's age and the response to ovarian stimulation. Design Observational study. Setting University and fertility clinic. Patients Sixty-four women (age 19-46), consisting of unfertile patients and oocyte donors, undergoing controlled ovarian stimulation. Interventions None. Main outcome measure(s) FF from small (< 12 mm) and large (≥ 18 mm) follicles was collected at oocyte retrieval. FAs by gas chromatography-flame ionization detection. Result Thirty-two FAs with chain lengths ranging from 14 to 25 carbons were identified. There was a readjustment in FA distribution as follicle size increased, raising very long-chain saturated FAs, nervonic (24:1n-9), arachidonic (20:4n-6), and n-3 polyunsaturated FAs (PUFA, P < 0.001), the latter mainly due to an increase in docosahexaenoic acid (22:6n-3, DHA). In large follicles, double bond and peroxidizability indices and total n-3 PUFA, particularly DHA, correlated positively with the woman's age and negatively with the number of total and mature oocytes, total and top-quality embryos, and fertilization rate. Conclusions We have described 32 FAs in ovarian FF, of which 16 changed their distribution with follicle size. The results also indicate that lower n-3 PUFA levels in large follicles, which are associated with younger women, predict a better response to ovarian stimulation based on the recovery of total and mature oocytes, total and top-quality embryos, and fertilization rate per cycle. Key message The fatty acid profile of ovarian FF changes as the follicle grows and lower n-3 PUFA levels in large follicles, associated with younger women, predict a better response to ovarian stimulation.

The Fatty Acid Composition of Human Follicular Fluid Is Altered by a 6‐Week Dietary Intervention That Includes Marine Omega‐3 Fatty Acids

“…Using a large cohort of New Zealand women ( n = ~ 1300) aged 15 to 65+ years, Crowe et al identified that concentrations of EPA and DHA in blood serum lipids increased with age (Crowe et al, 2008). Our findings of positive association of follicular fluid omega‐3 fatty acids with age, agree with previous description of such associations for EPA, DPA, and DHA (Ruiz‐Sanz et al, 2019). Higher omega‐3 fatty acids with age may relate to dietary or metabolic differences.…”

Oocytes of women who are obese or overweight have lower levels of n-3 polyunsaturated fatty acids compared with oocytes of women with normal weight

“…In animals, there are many examples of diet and body composition influencing the FA content of FF (32), cumulus cells (33,34), and oocytes (34). In humans, the FA profile of FF changes as the follicle grows (35). Elevated FF levels of FAs have been associated with poor cumulusoocyte morphology (31).…”

The fatty acid composition in follicles is related to the developmental potential of oocytes up to the blastocyst stage: a single-centre cohort study

“…As follicular fluid (FF) surrounds the maturing oocyte prior to fertilization, its characteristics can influence the outcome of assisted reproduction in terms of fertilization success, embryonic development, and pregnancy rate [ 13 ]. In FF, fatty acids (FA) play important roles as cellular energy sources, structural components of membranes, and precursors for prostaglandins and steroid synthesis [ 14 ].…”

“…In the study of O’Gorman et al [ 15 ] , non-cleaved oocytes (which fertilized normally but failed to cleave) showed an increased proportion of C16:0 in FF compared with oocytes which developed into early cleavage stage embryos, while the proportions of C18:0, C20:4n-6 and C22:6n-3 were lower. Ruiz-Sanz et al [ 13 ] showed that the levels of total n-3 polyunsaturated FA (PUFA), particularly C22:6n-3, as well as C20:4n-6 were significantly increased while lower levels of C18:3n-3 were noted in the FF of large compared to small follicles. However, investigations into the effect of FA available in the follicular environment on embryo development until day 5 are still lacking.…”