Corresponding author; viv.perry@nottingham.ac.uk
Neonatal death is increased if the fetus is male. Physiological mechanisms that may affect this condition are the focus of this study. Placental insufficiency has been associated with arterial Doppler assessment of blood flow to the fetus. Evidence is emerging of a sex specific difference in fetal and placental perfusion[1]. This study investigates the effects of dietary intervention at specific time points upon blood flow and its consequence upon placental and fetal growth trajectory.
360 primiparous females were selected from a range population and individually fed either high or low protein diet 60d prior to conception and 98 days post conception (dpc). 120 became pregnant of which 48 fetuses and placentae were excised at 98dpc. The pregnant females were ultrasound scanned for fetal development monthly from 36dpc until term at 280 dpc. This included Doppler scanning at 120, 150, 180, 210 dpc. Significant effects from Doppler assessment of uterine arterial flow were found for the preconception diet; these being confined to those females carrying male fetuses. Increased preconception dietary protein increased uterine artery; Pulsatility index PI 0.66 vs 0.74 p=0.03 at dpc120, Vmax 109 vs 120cm/s p= 0.01 at 150dpc, and reduced TAMV 156 vs 140 cm/s p =0.02 at 210dpc, in these females. Intriguingly, ongoing immunohistochemistry suggests differential development of blood vessels in the 98dpc placenta also dependent upon preconception diet while blood flow volume was affected by sex but not dietary intervention (Fig 1, dpc120 shown).

As reported in a concomitant report at this conference effects upon fetal growth were sex specific from 36 to 98dpc with the male feto placental unit significantly affected by the preconception diet (p=>0.05). In combination these results suggest preconception diet influences oocyte and embryo development which may have long term and sex specific effects for the offspring.

Acknowledgements: We are indebted to S.Kidman and Co., Ridley Agriproducts and ARC for funding this research.