Background: Adequate folate intake before and during early pregnancy is essential for neural tube defect (NTD) prevention. In 2023, the Polish Society of Gynecologists and Obstetricians updated national recommendations, emphasizing the use of L-5-methyltetrahydrofolate (5-MTHF). Evidence on women’s awareness of these guidelines is limited. Methods: This cross-sectional online survey (2025) included 188 Polish women aged 18–45 years who were currently pregnant or had been pregnant within the previous 12 months. Knowledge, attitudes, and supplementation practices were compared between women with (n = 94) and without infertility (n = 94). Group differences were assessed using χ2 tests, and predictors of 5-MTHF use were examined with multivariable logistic regression. Results: General awareness of folate recommendations was high (98.9%). However, detailed knowledge varied substantially. Women with infertility more frequently recognized different folate forms (87.2% vs. 72.3%; p = 0.018), knew the role of the MTHFR gene (77.7% vs. 39.4%; p < 0.001), and initiated supplementation ≥3 months before conception (88.3% vs. 47.9%; p < 0.001). Overall, 66% reported using 5-MTHF. Independent predictors of choosing 5-MTHF included awareness of folate forms, MTHFR knowledge, and awareness of emerging considerations related to folic acid metabolism. Infertility status was not an independent predictor. Conclusions: Although folate supplementation was nearly universal in this selective sample, more advanced knowledge—particularly regarding folate forms and genetic aspects of folate metabolism—remained limited. Higher awareness among women with infertility likely reflects greater exposure to medical supervision rather than inherent differences between groups. These findings may represent early signals of how the 2023 Polish recommendations are disseminating among women who are more engaged with health information, highlighting the need for continued public and professional education to support informed use of folate supplements.