Smoking in pregnancy is a key factor for sudden infant death among Māori

AIM

To examine the sudden unexpected death in infancy (SUDI) disparity between Māori and non-Māori in New Zealand.

METHODS

A nationwide prospective case-control study ran from March 2012 to February 2015. Exposure to established SUDI risk factors was analysed to investigate the disparity experienced by Māori. Infant ethnicity was based on mother's ethnicity. Māori ethnicity was prioritised. Non-Māori includes Pacific, Asian, NZ European and Other.

RESULTS

There were 137 cases and 649 controls. The Māori SUDI rate was 1.41/1000 live births compared to 0.53/1000 for non-Māori. Parents/caregivers of 132 cases (96%) and 258 controls (40%) were interviewed. Smoking in pregnancy was associated with an equally increased SUDI risk for Māori (adjusted OR = 8.11, 95% CI = 2.64, 24.93) and non-Māori (aOR = 5.09, 95% CI = 1.79, 14.47), as was bed-sharing (aOR = 3.66, 95% CI = 1.49, 9.00 vs aOR = 11.20, 95% CI = 3.46, 36.29). Bed-sharing prevalence was similar; however, more Māori controls smoked during pregnancy (46.7%) than non-Māori (22.8%). The main contributor relating to increased SUDI risk for Māori/non-Māori infants is the combination of smoking in pregnancy and bed sharing.

CONCLUSION

The association between known SUDI risk factors, including bed sharing and/or smoking in pregnancy and SUDI risk, is the same regardless of ethnicity. Māori infants are exposed more frequently to both behaviours because of the higher Māori smoking rate.

Development of an animal model to study congenital urinary obstruction

PURPOSE

We outline the development of a reliable model of obstructive uropathy in fetal lambs highlighting our understanding of the critical time points for interventions and the variability of any such model. We identify some discoveries that may have clinical implications.

METHODS

The model requires 60-day-gestation fetal lambs. In lambs, glomerulogenesis is complete by 90 days gestation. (Term is 145 days.) The ability to develop a reliable method of creating bladder outlet obstruction in females, ligating both the urethra and urachus was critical. The lambs are bred to an accuracy of ±24 h.

RESULTS

Creating the model at 50-60 days gestation, produces different expressions of renal dysplasia in groups of lambs undergoing identical interventions at the same stage of gestation. Early complete urethral obstruction can produce the Potter phenotype. An appropriately timed vesico-amniotic shunt preserves renal development, producing a shrunken, non-compliant bladder. Shunting the normal fetal bladder at 80 days gestation produces a similar bladder. Provision of a low-pressure valve in the shunt preserves bladder development and compliance. Using a high-pressure shunt produces results similar to non-shunted lambs.

DISCUSSION

We developed a reliable animal model for obstructive uropathy. Being alert to peripheral results can lead to new findings.

A case of amyoplasia in a monochorionic twin pregnancy: a sequela from twin-twin transfusion syndrome?

OBJECTIVE

To present and discuss the sonographic and clinical findings in one twin of a monochorionic pair affected by amyoplasia.

METHODS

On ultrasound examination at 21 weeks in a monochorionic twin pregnancy, twin I was smaller, hydropic, with multiple contractures consistent with amyoplasia and oligohydramnios. Twin II was anatomically normal with polyhydramnios.

RESULTS

The twins were delivered at 28 weeks' gestation. The clinical findings were consistent with twin-twin transfusion syndrome (TTTS).

CONCLUSION

It is postulated that TTTS may be a causative factor in the excessive incidence of amyoplasia in monozygotic twin pregnancy.

Potential confusion arising from materials presenting as possible human remains

The accurate identification of human tissues is an important part of forensic science, but may be difficult when specimens are small, fragmented, or burned. A wide variety of materials may be submitted as human, including parts of animals and nonorganic materials. Two cases involving a plastic fetal skeleton and a rubber fetus are described, which were initially considered to represent human remains, thus initiating police investigations for possible concealed stillbirth or infanticide. In one case, the remains were so deceptively real in appearance that hospital personnel initiated fibroblast cultures from an "umbilical cord". A third case of mineral concretions that resembled a human hand is also described. These cases demonstrate that protocols should be in place for the rapid assessment of all suspected human remains by pathologists, so that nonhuman material can be rapidly excluded, and police investigations terminated.

Different phenotypes of dysplastic kidney in obstructive uropathy in fetal lambs

PURPOSE

The cause of cyst production in renal dysplasia is uncertain. The authors hypothesized that different patterns of renal dysplasia result from variations in the timing and site of the urinary tract obstruction.

METHODS

The authors operated on fetal lambs at 50 and 60 days' gestation. Male lambs underwent urethral and urachal ligation and female lambs unilateral ureteric ligation. They were delivered by cesarean section at 145 days' gestation and killed.

RESULTS

Of 12 lambs operated on at 50 days' gestation, 4 survived. Of 26 lambs operated on at 60 days, 21 survived. The authors identified 3 types of dysplastic kidneys. Type A, fibrotic kidneys (2.2 g) with no cysts and interstitial fibrosis. There were reduced numbers of proximal tubules, but distal tubules and collecting ducts persisted. (50-day obstruction, n = 5 kidneys); type B, Sponge-like kidneys (37g): these had large cysts with minimal interstitial fibrosis. (87% of 60-day uretheral and urachal ligation model n = 12 kidneys); Type C, Small kidneys (4.8 g) with no large cysts (60-day Ureteric ligation model n = 7 kidneys).

CONCLUSION

The authors produced 3 different types of renal dysplasia by creating urinary tract obstruction at different sites and gestational ages.

Glomerular size in renal dysplasia secondary to obstructive uropathy: a further exploration of the fetal lamb model

BACKGROUND/PURPOSE

Creating an obstructive uropathy early in glomerulogenesis would produce multicystic dysplastic kidneys (MCDK). Measuring the mean planar area of the glomeruli (GMPA) may clarify the pathogenesis of MCDK.

METHODS

Fetal lambs at 60 days' gestation had their left ureter ligated and were delivered by cesarian section at 145 days' gestation. Kidney weight and length were recorded. GMPA in 3 zones (outer, middle, inner) of the sectioned kidney was measured using a computerized planimeter. The obstructed kidneys were compared with contralateral unobstructed kidneys. The unpaired Student's t test was used to determine significance.

RESULTS

One ewe miscarried. Four of 5 (80%) 60-day lambs survived. All had dysplastic kidneys. Mean kidney weights were 4.3 +/- 0.84 g in MCDK and 16.8 +/- 3.6 g in controls (P< .05). The GMPA of the outer, middle, and inner zones of the MCDK were 2.7 x 10(-3) mm2, 3.2 x 10(-3) mm2, and 4.0 x 10(-3) mm2, respectively. Controls were 2.8 x 10(-3) mm2, 4.4 x 10(-3) mm2, and 6.0 x 10(-3) mm2. The glomeruli of 60-day fetal kidneys were 3.0 x 10(-3) mm2, 6.1 x 10(-3) mm2, and 11.0 x 10(-3) mm2. MCDK had smaller glomeruli in the inner and middle zones than controls.

CONCLUSION

Fetal glomeruli appear to grow from the inner zone of the kidney. Early urinary tract obstruction stops this growth.

Lethal congenital dyserythropoietic anaemia type I in siblings presenting as pericardial effusions in the second trimester

Congenital dyserythropoietic anaemias (CDA) are rare inherited disorders of erythropoiesis characterised by abnormal red cell morphology and haemolysis. The diagnosis of CDA should be considered in the fetus or patient presenting with a normocytic or macrocytic anaemia especially if red cell morphology is abnormal. Three types and other possible variants have been described. There are few reports of clinical presentation of CDA in utero. We present 2 cases of lethal CDA in siblings that presented with pericardial effusions in the second trimester.

Outcome of antenatally detected cystic dysplastic kidney disease

Forty four fetuses with multicystic dysplastic kidney (MCDK) disease recognised on antenatal ultrasound were studied prospectively. In nine aborted fetuses and in five who died in the neonatal period the MCDK disease was bilateral or there were associated lethal abnormalities or syndromes. All surviving infants had unilateral disease and in six (20%) there was significant reflux into the normal contralateral kidney. Since 1988 the management of unilateral MCDK disease has been conservative with no child developing sepsis, hypertension, or malignancy. Serial ultrasound examinations suggest that MCDK lesions involute with time and conservative rather than operative management is favoured.

The outcome of fetal ventriculomegaly

Over a 5 year period 38 cases of fetal ventriculomegaly were diagnosed at Queen's Medical Centre, Nottingham. There were 12 cases of spina bifida and all patients opted for a termination of pregnancy. There were 15 cases of isolated ventriculomegaly comprising seven cases of aqueduct stenosis, four abnormalities of the corpus callosum, one cavum septum pellucidum cyst, one case of porencephaly and two cases of mild lateral ventricular dilatation. The fetuses in this group had a relatively good outcome with five babies showing normal development, three with mild development delay and one with moderate developmental delay. There was one stillbirth and five patients opted for a termination of pregnancy. Associated abnormalities were seen in seven cases and these carried a poor prognosis with one fetus stillborn, one neonatal death, and three patients opted for a termination of pregnancy. Two babies were liveborn, one has severe developmental delay and the other one is normal. The four remaining cases included two Dandy Walker syndrome, one brain tumour and one case of subdural haemorrhage. There were three terminations of pregnancy and one stillbirth in this group. The outcome of fetal ventriculomegaly depends on the presence of associated abnormalities which carry a poor prognosis. It also depends on the timing of the diagnosis as most patients will opt for a termination of pregnancy if the diagnosis is made before 24 weeks gestation. A review of the literature reveals that, excluding terminations, fetuses with isolated ventriculomegaly have an 80% chance of survival and a 50% chance of normal development.

The ultrasound markers of chromosomal disease: a retrospective study

Over a 3 year period 37 pregnancies were complicated by a chromosomal abnormality. In the two cases of trisomy 13, holoprosencephaly, facial clefting, polydactyly and growth retardation were seen. In the seven cases of trisomy 18, abnormalities of the extremities, face and heart were common. Growth retardation and diaphragmatic hernia were also demonstrated. In the 21 cases of Down's syndrome the main abnormalities were cardiac, duodenal atresia and subtle digital anomalies. The two fetuses with triploidy showed a large hydropic placenta and holoprosencephaly respectively, and all five cases of Turner's syndrome demonstrated a cystic hygroma two of which were associated with hydrops. From the antenatal scans major anomalies were detected in 18 fetuses, however, chromosomal disease was suspected in only 15 cases. This was in part owing to a high false negative rate for cardiac anomalies (14 cases) in both routine and detailed scans. Owing to the diversity of anomalies present in chromosomal disease full assessment of the fetus is recommended with particular attention to the fetal heart, face, hands and feet. Specific anomalies are suggested for karyotype.

Fetal choroid plexus cysts: a prospective study and review of the literature

To determine the incidence and significance of fetal choroid plexus cysts, a prospective study was carried out at Queen's Medical Centre, Nottingham. The incidence of cysts was found to be 0.42% and the size of cysts varied from 3 to 13 mm with a mean diameter of 6.2 mm. Choroid plexus cysts were associated with other fetal abnormalities in three cases, two of which were subsequently found to have a chromosomal abnormality, one Trisomy 18 and one Trisomy 21. A review of the reported cases of choroid plexus cysts reveals an overall incidence of 5.8% for Trisomy 18. We therefore recommend that in patients with choroid plexus cysts a detailed scan should be carried out to look for the ultrasound markers of Trisomy 18. If there is an associated abnormality or cysts are large (13 mm or greater in diameter) and bilateral then a karyotyping should be carried out.