67. Birthweight in pregnancies complicated by maternal heart disease

Objective To assess the mean and centile birthweight distribution in women with various groups of heart disease compared with controls. Methods Data on birthweight and gestational age at birth (⩾24 weeks gestation) were collected about women with known heart disease (both congenital and acquired) from seven specialist UK maternity units. Women were assigned to one of 16 groups according to their cardiac lesion. Whenever possible, data on two controls delivering before and after the index cases was also collected. Birth weight percentiles (corrected for gestational age, sex and parity) were calculated using the Aberdeen norms. Using multivariate regression, we also assessed the impact of beta blockers, maternal hypoxemia maternal saturations ( Results 1321 pregnancies in women with heart disease and 2307 controls were studied. All groups of women with heart disease had lower mean centile birthweight than controls, significantly so in 10 groups, the biggest effect being seen in women with Fontan circulation, pulmonary hypertension, prosthetic heart valves, systemic right ventricle, Marfan’s syndrome, repaired tetralogy of Fallot, and cardiomyopathy (in that order). Beta blockers, low maternal oxygen saturation, and impaired systemic ventricular function were also associated with significantly lower centile birthweights.Following multivariate regression; mean birthweight with beta blockers was 3116.7 g (SD 700.02) cf 3354.7 g (SD 539.06) without beta blockers, a difference of 238.1 g (p Conclusion Our findings identify specific groups of women with heart disease at risk of having a small baby who therefore need close surveillance of fetal growth.