post-HBO views the head is in the standard upright position. The transaxial slices are thus not comparable. Furthermore background and saturation levels are different in the two HBO studies: less background has been subtracted from the post-HBO study, which has the effect of making the post-HBO study appear enhanced. Technical factors provide the most plausible explanation for the SPET findings. This report does not support the use of HBO as a 1 treatment for stroke, a conclusion reached by others. Royal Naval Hospital Haslar, Gosport PO12 2AA, UK
M. A. MACLEOD
Institute of Naval Medicine
T. J. R. FRANCIS D. J. SMITH 1. Heimbach RD. Hyperbaric oxygen therapy and stroke. JAMA 1981; 245: 1873-74.
SiR,—In your Feb 17 editorial you say that not every woman wants immediate delivery following the diagnosis of intrauterine death and that 90% of patients will deliver spontaneously within 3 weeks-but you could have added that such labours will be quick and "easy" compared with labours following induction. The tragic effects of stillbirth on parents and nursing and medical staff are probably greater now that the expectations of a safe delivery of a healthy baby are so high. If the grief and distress associated with stillbirth are bypassed there is a danger of promoting various severe psychological complications.1 Support services following perinatal death have proved to reduce psychiatric disorder.2 My own practice3 over many years has been to discuss the possibilities with the patient and her partner and most have chosen to wait for spontaneous onset of labour. Some have changed their mind after about a week whereas other have waited longer to do so—even up to 5 weeks. The consultant sees the patient and her partner as soon as possible after diagnosis; there is close liaison with the community and delivery suite teams so that everyone in contact with the patient is aware of the situation and provides support. Ideally the consultant is present at delivery, the patient is encouraged to hold her baby, and a photograph is offered; time is allotted at the postnatal visit for full discussion. Coagulation studies are done weekly, and no abnormality has yet occurred. You describe "the erroneous impression that just because the baby died, it has suddenly become abhorrent and needs to be delivered as soon as possible". The same reasoning could be applied when the baby in utero proves to have a lethal congenital abnormality. "To me my baby was lovely"-so spoke a mother who 24 hours earlier had given birth to a baby with multiple abnormalities. The baby died 20 minutes after birth. Her words, said reproachfully, made me realise that there was something lacking in the management of such problems. Immediate delivery may initially seem the ideal answer, but even if it were available without accompanying drawbacks it may seem disrespectful to the couple if the baby is got rid of in unseemly haste. Birmingham Maternity Hospital, Queen Elizabeth Medical Centre, Edgbaston, Birmingham B15 2TG, UK
1. Bourne S. Stillbirth, grief and medical education Br Med J 1977; i: 1157. 2. Forrest JC, Standish E, Baum JD. Support after perinatal death: a study of support and counselling after perinatal bereavement. Br Med J 1982; 285: 1475-79. 3 Kelly J The management ofpatients with an intra-uterine death or a fetal abnormality. J Psychosom Obstet Gynaecol 1983; 2: 168.
Dietary calcium supplementation and prevention of pregnancy hypertension SjR,—Dr Lopez-Jaramillo and colleagues (Feb 3, p 293) confirm earlier findings and those of others that calcium supplementation reduces the frequency of pregnancy-induced hypertension. Having previously shown that supplementation caused a small but significant increase in ionised calcium,l they speculate that hypertension in pregnancy may be secondary to their
lowered ionised calcium.
exception, ionised calcium measured in anaerobic reported to be unchanged or decreased during normal pregnancy. However, ionised calcium analysers are affected by serum albumin, giving lower values in the presence of a low albumin concentration.3 Since serum albumin falls by about 10 g/1 during normal pregnancy, a rise in ionised calcium might be obscured by the fall in albumin. We studied 42 pregnancies in 41 healthy women and found that albumin-adjusted calcium concentration rose linearly from conception to term by an average of 0-16 mmol/1.2 When considered with published observations of of concentrations 1,25increasing hypercalciuria4 dihydroxycholecalciferol, possibly of placental origin, 4-6 and decreased concentrations of intact parathyroid hormoneour findings strongly suggest that true ionised calcium increases throughout normal pregnancy. Thus, calcium supplementation may reduce the frequency of pregnancy-induced hypertension by facilitating the physiological increase in serum calcium, rather than by preventing a fall. With
Department of Chemical Pathology, St James’s University Hospital, Leeds LS9 7TF, UK 1.
R. B. PAYNE R. T. EVANS
Narvaez M, Weigel RM, Yepez R. Calcium supplementation reduces the risk of pregnancy-induced hypertension in the Andes population. Br J Obstet Gynaecol 1989; 96: 648-55. Payne RB, Little AJ, Evans RT. Albumin-adjusted calcium concentration in serum increases during normal pregnancy. Clin Chem 1990; 36: 142-44. Butler SJ, Payne RB, Gunn IR, Burns J, Paterson CR. Correlation between serum ionised calcium and albumin concentrations in two hospital populations. Br Med J 1984; 289: 948-50. Kumar R, Cohen WR, Silva P, Epstein FH. Elevated 1,25- dihydroxyvitamin D plasma levels in normal human pregnancy and lactation. J Clin Invest 1979; 63: 342-44. Gertner JM, Coustan DR, Kliger AS, Mallette LE, Ravin N, Broadus AE. Pregnancy as state of physiologic absorptive hypercalciuria. Am J Med 1986; 81: 451-56. Okonofua F, Menon RK, Houlder S, et al. Calcium, vitamin D and parathyroid hormone relationships in pregnant Caucasian and Asian women and their neonates. Ann Clin Biochem 1987; 24: 22-28. Davis OK, Hawkins DS, Rubin LP, Posillico JT, Brown EM, Schiff I. Serum parathyroid hormone (PTH) in pregnant women determined by an immunoradiometric assay for intact PTH. J Clin Endocrinol Metab 1988; 67: 850-52.
Predicting trends in operative delivery for cephalopelvic disproportion in Africa SIR,-In much of Africa growth stunting from the combined effects of poor childhood nutrition and infection is common, and cephalopelvic disproportion is the major obstetric complication. In reproductive terms short women and those who fail to receive antenatal care compare very badly with tall women and those who do receive antenatal care. I wondered if data from the Zaria Birth Survey1 could be used to predict how maternal height and fetal birthweight will vary and how the operative delivery rate (caesarean section and embryotomy combined) might change when nutrition improves and antenatal care becomes universally accepted. All 4702 births to primigravidae in hospital and with complete data on maternal height (116-193 cm) and birthweight (600-4400 g) were divided into fifteen groups, of average size 313 and range 23 to 1063 births. The operative delivery rate rose with increasing birthweight but fell with increasing maternal height (figure); it was 57% in short primigravidae (150 cm and under) who had babies weighing 3510 g or more and less than 6 % in tall primigravidae who gave birth to well-grown babies. Antenatal care greatly influenced birthweight. Of the first-born babies whose mothers had had antenatal care, 14% weighed 2500 g and less, 76% between 2510 and 3500 g, and 10% were 3510 or more; the figures for the group without antenatal care were 31%, 65%, and 4%, respectively. This information allows us to predict the operative delivery pattern once standards of nutrition and basic health care improve and antenatal care is generally accepted. Soon after these changes begin children will attain better growth rates, as will the babies because of improved intrauterine nutrition. However, in most pregnant women skeletal growth will already have ceased, so for a time there will be many women of short stature bearing heavy babies. One generation later the childbearing population