Periconceptional maternal ‘high fish and olive oil, low meat’ dietary pattern is associated with increased embryonic growth: The Rotterdam Periconceptional Cohort (Predict) Study

Objective: To investigate the association between periconceptional maternal dietary pattern and first-trimester embryonic growth. Methods: This was a prospective cohort study of 228 women with a singleton ongoing pregnancy, of which 135 were strictly dated spontaneous pregnancies and 93 were pregnancies achieved after in-vitro fertilization or intracytoplasmatic sperm injection (IVF/ICSI). All women underwent serial transvaginal three-dimensional ultrasound (3D-US) examinations from 6 + 0 to 13 + 0 weeks' gestation. Crown–rump length (CRL) and embryonic volume (EV) measurements were performed using a virtual reality system. Information on periconceptional maternal dietary intake was collected via food frequency questionnaires. Principal component analysis was performed to identify dietary patterns. Associations between dietary patterns and CRL and EV trajectories were investigated using linear mixed models adjusted for potential confounders. Results: A median of five (range, one to seven) 3D-US scans per pregnancy were performed. Of 1162 datasets, quality was sufficient to perform CRL measurements in 991 (85.3%) and EV measurements in 899 (77.4%). A dietary pattern comprising high intake of fish and olive oil and a very low intake of meat was identified as beneficial for embryonic growth. In strictly dated spontaneous pregnancies, strong adherence to the ‘high fish and olive oil, low meat’ dietary pattern was associated with a 1.9 mm (95% CI, 0.1–3.63 mm) increase in CRL (+14.6%) at 7 weeks and a 3.4 mm (95% CI, 0.2–7.81 mm) increase (+6.9%) at 11 weeks, whereas EV increased by 0.06 cm3 (95% CI, 0.01–0.13 cm3) (+20.4%) at 7 weeks and 1.43 cm3 (95% CI, 0.99–1.87 cm3) (+14.4%) at 11 weeks. No significant association was observed in the total study population or in the IVF/ICSI subgroup. Conclusion: Periconceptional maternal adherence to a high fish and olive oil, low meat dietary pattern is positively associated with embryonic growth in spontaneously conceived pregnancies.