AMOSS (Australasian (Australia and New Zealand) Maternity Outcomes Surveillance System) studies rare and serious conditions in pregnancy, including rheumatic heart disease (RHD). Pregnant women with RHD were prospectively identified throughout New Zealand between October 1st , 2012 - December 31st, 2014, to determine the numbers affected by RHD in pregnancy, the degree of severity of RHD and outcomes for mother and baby.
147 pregnancies, occurred in 130 women, 64 (44%) Maori, 74 (50%) Pacific. Ages ranged from 15-43 years. 16 women (11%) were diagnosed with RHD for the first time. 41 (28%) women had severe RHD. 24 (16%) women had had previous cardiac surgery including 13 (9%) with mechanical valves.
Cardiac complications occurred in 24/147 (15.6%) pregnancies. 5 women with less than severe RHD were assessed for shortness of breath or palpitations and 1 (moderate mixed mitral valve disease) admitted for medical stabilisation. 19 women with severe RHD presented with acute pulmonary oedema or atrial fibrillation, managed medically apart from 2 requiring balloon mitral valvotomy and 2 urgent valve surgery. There were no maternal deaths.
Infant outcomes included miscarriage or termination 14 (9.6%), still birth 2 (1.5%) and preterm birth 15 (11.4%). Mean birth weight 3295g (410-5300g). There were 88 (60.3%) spontaneous vaginal deliveries, 42 (32.8%) inductions and 31 (23.5%) Caesarian sections.
Most mothers and babies did well. With known disease, echocardiography in pregnancy is required for risk stratification. In NZ, RHD occurs in pregnancy in 1/500 Maori and 1/200 Pacific women. Screening echocardiogram should be considered in these women.