I. R. McFADYEN

The relation of birthweight to histological appearances in vessels of the placental bed

Summary. Biopsy of the placental bed was attempted at caesarean section in 109 patients: 77 consecutive and 32 selected because of the maternal or fetal condition. Forty‐seven (44%) of these biopsies were from the placental bed and contained spiral arteries suitable for comment. Histological examination separated the patients into four groups: comprising 11 whose vessels showed normal physiological changes, 20 who showed inadequate physiological change, 12 with acute atherosis, and four with a mixed pattern. There was no relation between these changes and maternal age, parity, race or smoking habit, but no physiological change and atherosis were more common in association with maternal hypertension. Mean adjusted birthweight was greatest in those with physiological changes, less in those without physiological changes or the mixed pattern, and least in those with atherosis. The four patients in the mixed group did not have any unifying clinical characteristics.

Zinc and copper in Asian pregnancies–is there evidence for a nutritional deficiency?

Summary. In 92 Hindu Asians, 59% of them vegetarian, and 51 Europeans longitudinal measurements were made during pregnancy of the zinc and copper concentrations in plasma and hair together with urinary zinc excretion, as indices of their zinc and copper status. Maternal diets were assessed once at booking. Zinc intakes ranged from 3·1 to 16·9 mg/day, with average intakes least in vegetarian Hindus and most in Europeans. Average copper intakes ranged between 1·48 and 1·80 mg/day and were similar in the three patient groups. Both ethnic groups showed the pregnancy‐associated fall in the plasma concentration of zinc and rise in that of copper but throughout the study Hindus had statistically significant lower levels of zinc and higher levels of copper than Europeans. Urinary zinc excretion was not only significantly lower throughout the study in Hindus than in Europeans but the increase in excretion which occurred after 20 weeks gestation was smaller. There were no ethnic differences in the zinc content of hair. Urinary zinc excretion correlated with both plasma zinc levels and dietary zinc. Mean birth‐weight in the Hindus was 2912 g and 34% of infants were below the 10th centile, using the Aberdeen standards, compared with 6% of the European babies (mean birthweight 3349 g). No association was found between crude or adjusted birthweight and any of the measures of zinc or copper status in either ethnic group. The Hindus had an apparently lower average zinc status than the Europeans, but there was no evidence that this had acted as a nutritional constraint and was the cause of their slower rate of intrauterine growth.

THE PHYSIOLOGICAL MACROCYTOSIS OF PREGNANCY

Sixty‐four healthy women were followed during normal pregnancies in which they took supplements of iron or iron+folate or an inactive placebo. The red cell size increased in those patients receiving iron alone or iron+folate. The group on the inactive placebo who received no supplemental iron had red cells of constant size and a falling serum iron. Nineteen women not included in the trial developed macrocytosis during pregnancy: marrow samples from these showed normoblastic erythropoiesis in 18 and minor megaloblastic changes in one. Macrocytosis developing during pregnancy is a physiological change in the majority of cases.

Factors affecting birthweights in Hindus, Moslems and Europeans

Summary. The birthweights of 664 Hindu and 132 Moslem babies were compared with those of 486 European babies born at the same hospital. The mean birthweight of the Europeans was 3362 g, compared with 3146 g for the Moslems and 2960 g for the Hindus. The Asian women were smaller than the European and tended to have a shorter length of gestation. Forty‐four per cent of the Asians and 46% of the European mothers were of social classes I and II; 28% of the Europeans and 2% of the Asians smoked. There were no significant differences between Asians and Europeans in the effects of maternal size, parity, gestational age and fetal sex on birthweight. After adjustment for these variables and for cigarette smoking there was no significant difference in birthweight between the Moslems and the Europeans, but the mean birthweight of the Hindus was about 190 g lighter than that of the Europeans. Hindus from East Africa had lighter babies than those from India.

Fetal urinary tract obstruction: is active intervention before delivery indicated?

Summary. Obstruction of the urinary tract was diagnosed by ultrasound in four fetuses at 16—30 weeks: three of these diagnoses were confirmed after delivery; the fourth fetus had multicystic kidneys with hydroureter and hydronephrosis but no obstruction. The fetus with obstruction diagnosed at 16 weeks was terminated: it had lung hypoplasia with the prune‐belly syndrome. The other two fetuses with obstruction were diagnosed at 25 and 34 weeks; the urinary tracts of both were drained for 5–14 days with reduction of distension. Both were born alive but that diagnosed at 25 weeks died of lung hypoplasia, the other survived, required nephrectomy and at the age of 3 is small but developing normally. Fetal urinary tract obstruction may prevent normal development of the lungs, be associated with other anomalies which cannot be diagnosed before delivery and retard infant development in survivors. Drainage of the dilated urinary tract does not harm the fetus or mother but has not been shown to improve neonatal survival or infant development.

Bacteriuria in pregnancy treated with a single dose of cephalexin

Summary. Of 87 women in whom bacteriuria was diagnosed on dip slides at between 9 and 22 weeks gestation only 51 (59%) had true bacteriuria in urine obtained by suprapubic aspiration. A single oral dose of cephalexin (3 g) was given to 37 of these patients, 10 were Indian and none of them had recurrence of infection after treatment, whereas 11 of the 27 (41%) ‘indigenous’ women again had bacteriuria within 2 weeks of treatment. None of the other 26 patients had recurrent bacteriuria in the pregnancy studied. Success of treatment was not related to renal concentrating ability nor, apart from ethnic group, were there other significant differences between successes and failures. Although single‐dose treatment seems to be less effective in pregnancy than in the non‐pregnant patients, it is an acceptable method of treatment provided that all treated patients are followed closely to detect those who do not respond and require further therapy.

High oestrogen excretion in pregnancy

Summary. Fifty‐one women with singleton pregnancies whose urinary oestrogen excretion was above the 95th centile of the hospitals reference range on two or more occasions were reviewed. The women did not differ from the general population in race, parity, age, height or weight gain during pregnancy, but they were slightly heavier. Fetal and placental weights were greater than the corresponding values in the general population, as were the volumes of urine containing the oestrogen, but none of these differences was sufficient to account for oestrogen excretion above the 95th centile. Eleven patients, has a glucose tolerance test, two of them had abnormal results and nine had normal results but heavy babies. Patterns of oestrogen excretion did not identify a high‐risk population but the women with consistently high excretion gave birth to eight of the nine babies that weighed 4 kg in this population. Twenty‐two of the women had 23 subsequent pregnancies in which oestrogen excretion was measured: excretion was normal in 17, low in two and above the 95th centile in four.

The relation between plasma urate and placental bed vascular adaptation to pregnancy

Summary. Placental bed biopsies were obtained at caesarean section from 34 women. Their plasma urate was directly related to maximum mean arterial pressure and inversely to adjusted birthweight; but it was related most closely to the histological appearances of the spiral arteries in the placental bed. Nine women had physiological changes in the spiral arteries: their mean urate (233, SD 28·9 μmol/l) was significantly (P <0·00l) lower than the mean urate in those who did not have adequate physiological changes (339, SD 90·3 μmo1/l) or that in the nine women who had atherosis (397, SD 153·2 μmol/l). Raised plasma urate appears to be better related to maternal vascular pathology than to the clinical condition or infant birthweight.

Concentrations of hypoxanthine, xanthme, undine and urate in amniotic fluid at caesarean section and the association of raised levels with prenatal risk factors and fetal distress

Summary. Samples of amniotic fluid were obtained at caesarean section from 33 of 80 consecutive unselected patients in whom the membranes were intact. Concentrations of the ATP metabolites, hypoxanthine and xanthine, as well as uridine and urate were determined using high pressure liquid chromatography. Independent ‘clinical’ factors associated with reduced fetal growth and well‐being were identified and the patients were assigned to one of three groups: those with no recognized risk, those with moderate risk and a small group of four patients with high risk. The mean hypoxanthine concentration was higher in the moderate‐risk group than in the group with no risk. Two of the three patients with proteinuric hypertension in the high‐risk group had normal hypoxanthine concentrations. There were seven patients with fetal distress, and concentrations of hypo xanthine, xanthine, uridine and urate were significantly higher in the three patients who had meconium stained amniotic fluid in addition to abnormal fetal heart rate tracings than in the remaining four who had fetal heart rate abnormalities only. It is suggested that fetal distress at emergency caesarean sections might be quantitated by such analysis.

THE DETERMINATION OF A REFERENCE RANGE FOR URINARY OESTROGEN EXCRETION IN LATE PREGNANCY

A reference range for urinary oestrogen excretion between 28 and 40 weeks has been produced by analysis of 18 870 estimations. The data were transformed logarithmically to give a Gaussian distribution on which parametric analysis was performed: non‐parametric analysis was carried out on the untransformed data : the results of both analyses were compatible. Multiple pregnancies tended to have levels above the 50th centile, light‐for‐dates fetuses below the 50th centile. Antepartum haemorrhage showed no difference from the general reference range. Intrauterine death was preceded by a level below the 5th centile if the estimation was carried out less than one week before the fetus died.