Folic acid (FA) can reduce the risk for selected birth defects other than neural tube defects. We examined whether FA has preventive effects against fetal abdominal wall defects (AWD) in a unique intervention cohort in China. Birth outcomes of 247 831 singleton births from a population-based cohort study with detailed pre-conceptional FA intake information were collected in China in 1993–1996. Information on births at 20 complete gestational weeks, including live births, stillbirths and pregnancy terminations, and all structural birth defects regardless of gestational week were recorded. The birth prevalence of omphalocele, gastroschisis and total fetal AWD was classified by maternal FA supplementation. The prevalence of total AWD was 4·30 per 10 000 births among women who took FA compared with 13·46 per 10 000 births among those who did not take FA in northern China and 6·28 and 5·18 per 10 000 births, respectively, in southern China. The prevalence of omphalocele was 0·54 per 10 000 births among women who took FA compared with 3·74 per 10 000 births among those who did not take FA in northern China and 1·79 and 1·44 per 10 000 births, respectively, in southern China. FA supplementation significantly prevented total AWD in multivariate analysis (relative risk 0·26, 95 % CI 0·11, 0·61) in northern China, although no preventive effect of FA on AWD was observed in southern China. FA supplementation successfully reduced the prevalence of AWD in northern China.

Pentalogy of Cantrell is characterised by a combination of severe defects in the middle of the chest including the sternum, diaphragm, heart, and abdominal wall. Mortality rate after cardiac surgery is usually high. We report a successful total correction of the cardiac defects in a case of Pentalogy of Cantrell with a double-outlet right ventricle prior to abdominal wall defect repair.

Omphaloceles and left ventricular diverticulums are rare disorders. Although either is known to occur on its own, the combination is highly suggestive of the so-called pentalogy of Cantrell. This syndrome is a combination of deformities involving midline structures, with exteriorisation of the heart, or ‘ectopia cordis’, as the most severe malformation. A cause has yet to be identified, though genes located on the X-chromosome may be involved. We discuss a neonate who presented with an omphalocele and a palpable diverticulum of the left ventricle. An omphalocele, especially when above the umbilicus, is an indication for further investigation for deformities as seen in the spectrum of Cantrell's pentalogy, especially cardiac malformations and anterior diaphragmatic herniation. A left ventricular diverticulum is usually associated with Cantrell's syndrome. When found, it is usually accompanied by other intracardiac malformations, so that again further examination is indicated. In our patient, there was an atrial septal defect within the oval fossa, along with a ventricular septal defect and unobstructed albeit anomalous venous pulmonary return to the left atrium. Early surgical intervention seems to be indicated, as spontaneous rupture, arrhythmias, and thromobogenicity of the ventricular diverticulum have all been reported.

Monozygotic twins with typical trisomy 13 are reported. Despite an identical karyotype, the twins were dimorphic for the presence of an omphalocele. Reasons for the rarity of MZ twins with trisomy 13 are presented. It is suggested that the presence of a chromosomal abnormality in MZ twins may predispose to dimorphism.

Two cases of holoacardius are presented. Both had a normal 46,XX female karyotype, identical to that of their respective cotwin. Data are presented supporting the concept that the placental vascular anastomoses are the primary agents in the formation of an acardiac. Cytogenetics, epidemiology and other theories of pathogenesis are discussed.