Table 2.
The effect of several nutritional factors and dietary patterns on ART outcomes.
| Assisted reproductive technologies | |||
|---|---|---|---|
| Nutrients | Study type/population | Findings | Evidence* |
| Proteins |
Animal proteins: - Cohort study/Women undergoing ICSI (35) - Cohort studies/Women undergoing ICSI, ART (35, 36) |
Animal proteins: - Red meat intake negatively correlates with embryo development and pregnancy rate (35) - Seafood sourced proteins increase likelihood of blastocyst formation and live births rate (35, 36) |
+ |
|
Plant proteins: - Cohort study/Women undergoing ART (37) - RCTs/Infertile women (38), Women undergoing IVF (39) - Cross sectional study/Women cohort (12) - Cohort studies/Women undergoing IVF (40), healthy women (41) |
Plant proteins (soy intake): - Isoflavones supplementation increased pregnancy and live births rate, progesterone, endometrial thickness (37, 38, 42) - Soy intake shows no/reduced likelihood of pregnancy and female fecundability (12, 40, 41) |
± | |
| Carbohydrates |
Sugars: - RCT/Obese and overweight infertile women (43) - Cross sectional study/Women eligible for IVF (44) - Cohort study/ Infertile couples eligible for IVF (45) |
Sugars: - Low glycemic load diet is associated with the number of retrieved oocytes, spontaneous pregnancy, and live birth rate (43) - High glycemic load is associated with poor ovarian response (44) - No association is observed between dietary glycemic load and IVF outcomes (45) Fibers: |
± |
|
Fibers: - Cross sectional study/Women eligible for IVF (44) - Cohort study/Infertile couples eligible for IVF (45) |
- Poor ovarian response (44) - No association between fiber intake and IVF outcomes (45) |
± | |
| Fat |
PUFA: - RCT/Overweight and obese women undergoing IVF (46) - Cohort studies/Women undergoing IVF and ICSI (18, 47) - RCT/Couples undergoing IVF and ICSI (48) - Cohort studies/Women undergoing IVF (49–51) |
PUFA: - ω-3/ ω-6 PUFA intake is associated with improved pregnancy rates (46) - ω-3 PUFA is associated with estradiol (E2) levels, embryo morphology, number of follicles, pregnancy and birth rates (18, 47) - ω-3 PUFA combined with vitamin D supplementation improved embryo quality (48) - contrasting data show different PUFA associated with decreased chance of pregnancy development (49–51) and no association between ω-3 PUFA and IVF outcomes (51) |
± |
|
Trans-fatty acids: - Cohort study/Women undergoing IVF (51) |
Trans-fatty acids: - The intake negatively correlates with IVF fertilization rate and blastulation rate (51) |
+ | |
| Vitamins |
Multivitamins: - Cohort study/Women underwent ART (52) |
Multivitamins: - The combination of multivitamins, whole grains, soy foods, dairy, fruits and vegetables (“pro-fertility diet”) is associated with an increased likelihood of live birth (52) |
+ |
|
Folate: - Cohort study/Women undergoing ART (5) - RCT/Women undergoing IVF (53) |
Folate: - Intake is associated with improved ART outcomes (5, 53) |
++ | |
|
Vitamin D: - Cohort studies/Women undergoing IVF (54–57) - RCT (58), cohort study (59) and cross-sectional study (60)/Women undergoing IVF |
Vitamin D: - High serum level is associated with high pregnancy and live births rate (54–57) - Contrasting data show no association of vitamin D levels with pregnancy rate and number of collected fertilized oocyte (58–60) |
± | |
| Minerals |
Zinc: - RCTs (61, 62), cohort study (63)/Women undergoing IVF - Cohort study/Women undergoing IVF (64) Selenium and copper: - RCTs (61, 62), cohort study (63)/Women undergoing IVF |
Zinc: - The level of zinc is restored after dietary supplementation indicating its possible role in improving fertility rates and ART outcomes (61–63) - In contrast, no association between the level of zinc, calcium and copper and follicle volume, oocyte fertilization rate and number of oocytes (64) Selenium and copper: - Follicular level of selenium and copper impact the quality of the microfollicular environment (61–63) |
± |
| Dietar patterns |
MedDiet: - Cohort studies/Couples undergoing IVF and ICSI (65–68) - RCT/Couples undergoing IVF and ICSI (48) - Cohort study/Couples undergoing IVF (69) |
MedDiet: - Increased fertilization rate, embryo yield, likelihood of pregnancy and live births rate (65–68) - Associated with embryos with shortened fourth cell cycle (CC4) and synchrony of the third cell cycle (S3) (48) - Contrasting study shows no association with IVF outcomes (69) |
± |
|
Western-like diet: - Animal study/Rhesus Macaques (70) |
Western-like diet: - Increased proinflammatory intrafollicular microenvironment and impaired preimplantation development (70) |
+ | |
*
+ limited evidence; ++ moderate evidence; ± conflicting evidence.
ICSI, intracytoplasmic sperm injection; IVF, in vitro fertilization; PUFA, polyunsaturated fatty acids; DHA, docosahexaenoic acid; ART, assisted reproductive technology; RCT, randomized controlled trial.