Contribution of congenital malformations to perinatal mortality. A 10 years prospective regional study in The Netherlands.

Objective: : To determine the precise contribution of congenital malformations to perinatal mortality in a region.
Design: Prospective, descriptive.
Setting: Region, Delft-Westland-Oostland (DWO) in the Netherlands.
Material and Methods: The registration was based on data concerning all deliveries of women domiciled in the health region DWO of the Netherlands. The incidence and contribution of congenital malformations to perinatal death was evaluated by a team consisting of a gynaecologist. a paediatrician and a paediatric pathologist. Malformations were classified as lethal or nonlethal and recorded separately for stillbirth (from 28 weeks gestation) and liveborn infants with 7-day follow-up.
Results: In 10 years (1993-1992) 28983 children were born in the region DWO. The perinatal mortality was calculated as 247 cases (0.85%). The overall incidence of congenital malformations in the perinatal death-group was 33%. Lethal congenital malformations were found in 51% of the cases in the stillbirth-group and 70% of the cases in the neonatal death-group. Congenital malformations of the central nervous system are mostly lethal in the stillbirth-group (45%). Cardiovascular- and pulmonary-defects were more prominent in the neonatal period (27% and 33% respectively of the neonatal deaths). Uro-genital and minor malformations (miscellaneous) are more often seen in perinatal deaths without being a contributor to the cause of death.
Conclusions: As most congenital malformations are multifactorial in origin, it is in the understanding and control of such conditions that efforts and resources should now be turned. Through a detailed postmortem fetal and placental examination and clinical-pathological correlations lethal congenital malformations were found in 51% in stillbirths (mainly central nervous system) and 70% in neonates (mainly cardiovascular and pulmonary defects).