RESUMEN
OBJECTIVE: In 1991, the Medical Research Council (MRC) Vitamin Study demonstrated that folic acid taken before pregnancy and in early pregnancy reduced the risk of a neural tube defect (NTD). We aimed to estimate the number of NTD pregnancies that would have been prevented if flour had been fortified with folic acid in the UK from 1998 as it had been in the USA. DESIGN: Estimates of NTD prevalence, the preventive effect of folic acid and the proportion of women taking folic acid supplements before pregnancy were used to predict the number of NTD pregnancies that would have been prevented if folic acid fortification had been implemented. SETTING: Eight congenital anomaly registers in England and Wales. MAIN OUTCOME MEASURES: The prevalence of pregnancies with an NTD in the UK and the number of these pregnancies that would have been prevented if folic acid fortification had been implemented. RESULTS: From 1991 to 2012, the prevalence of NTD pregnancies was 1.28 (95% CI 1.24 to 1.31) per 1000 total births (19% live births, 81% terminations and 0.5% stillbirths and fetal deaths ≥20â weeks' gestation). If the USA levels of folic acid fortification from 1998 onwards had been adopted in the UK, an estimated 2014 fewer NTD pregnancies would have occurred. CONCLUSIONS: Failure to implement folic acid fortification in the UK has caused, and continues to cause, avoidable terminations of pregnancy, stillbirths, neonatal deaths and permanent serious disability in surviving children.
Asunto(s)
Harina/análisis , Ácido Fólico/administración & dosificación , Alimentos Fortificados , Defectos del Tubo Neural/prevención & control , Aborto Inducido/estadística & datos numéricos , Inglaterra/epidemiología , Femenino , Humanos , Recién Nacido , Defectos del Tubo Neural/epidemiología , Atención Preconceptiva/métodos , Embarazo , Atención Prenatal/métodos , Prevalencia , Sistema de Registros , Gales/epidemiologíaRESUMEN
AIMS: The reason for the fivefold increased risk of stillbirth in women with diabetes is not known. Further understanding of the underlying mechanisms may facilitate identification of pregnancies at increased risk. We have compared post-mortem reports in matched pairs of stillbirths in women with and without diabetes. METHODS: Post-mortem reports were provided by the Centre for Maternal and Child Enquiries. Stillbirths as a result of lethal congenital and genetic abnormalities were excluded. Whole body, placenta and organ weights and histo-pathological findings in cases and controls were compared and also related to published reference values. RESULTS: We analysed post-mortem reports on 23 matched pairs of stillbirths from 2009 to 2010. Mean placental weight in women with diabetes was 75 g less than in control subjects (95% CI -143 to -7 g; P = 0.032). In maternal diabetes, the thymus was often small and showed a 'starry sky' pattern on histology in 11 of 20 cases compared with four of 22 controls (P = 0.03). This histological finding was associated with a particularly low mean placental weight z-score -2.1 (1.1) standard deviations below a reference population corrected for gestational age. CONCLUSIONS: In over half of the stillbirths occurring in women with diabetes, there was a 'starry sky' appearance in the fetal thymus on histology, this being associated with a small placenta. These findings are consistent with a critical subacute metabolic disturbance being a prominent cause of the increased risk of stillbirth in pregnancies complicated by maternal diabetes.