Low hemoglobin in late pregnancy reflects plasma volume changes, rather than poor maternal nutrition or adaptation, and is not linked to discordant placenta to birth weight ratio.

Serum ferritin, total plasma ferritin and haematological indices were determined during and for 6 months after normal pregnancy in 45 healthy women, 21 of whom took oral iron supplements. The physiological effect of pregnancy was to markedly depress serum ferritin concentration. During unsupplemented pregnancy median serum ferritin concentration decreased to approx. 6.0 pg/l by 28 weeks gestation, this concentration was maintained until term and was associated with the appearance of erythrocyte microcytosis during the third trimester. At 6 months postpartum, individual and average serum and total plasma ferritin values showed a deficit compared with the values recorded at the beginning of pregnancy. Oral iron supplementation during pregnancy modified the fall in serum ferritin, median serum ferritin concentrations remained about 14.0 Fg/1 after 28 weeks gestation; normocytic erythropoiesis was maintained throughout the third trimester and no deficit in serum and total plasma ferritin occurred as a result of pregnancy. It is concluded that routine oral iron administration should be recommended during pregnancy, certainly after 28 weeks gestation.During pregnancy, iron is required for the developing fetus, placenta and increasing maternal erythrocyte mass in addition to the normal daily requirements of a non-pregnant woman. The ability of a pregnant woman to meet these extra demands will depend on her dietary *Present address: Senior Lecturer,

Red cell mass, derived from plasma volume and haematocrit, was calculated serially in 45 healthy women during pregnancy and 4 to 6 months after delivery. Compared to the non-pregnant, postpartum value there was a reduction of approximately 100 ml at 12 weeks gestation. An increase in red cell mass occurred thereafter: at 36 weeks gestation values 180 ml greater than the non-pregnant were found. Iron and folic acid supplements almost double,d this increment to 349 ml of red cells.

No abstract

Objective-To determine whether the increased iron demands of pregnancy could be met by increased absorption from dietary sources.Design and setting6-Longitudinal prospective study in the research unit ofa maternity hospital.Subjects Main outcome measures-Serum samples were taken for 10 hours after administration of the isotopes; ratios of the isotopes were measured by inductively coupled plasma mass spectrometry, and the absorption oforal iron was calculated.Results-The geometric mean (95% confidence interval) absorption of iron at 12, 24, and 36 weeks' gestation was 7% (5% to 11%), 36% (28% to 47%), and 66% (57% to 76%) respectively. At 16-24 weeks after delivery the absorption was 11% (6% to 21%). The mean increase in absorption at 36 weeks (compared with that at 12 weeks) was 9*1 times (6.0 to 13.7). One pregnant woman developed iron deficiency anaemia but was otherwise indistinguishable from the others.Conclusions-An increase in the absorption of iron from food is a physiological consequence of normal pregnancy, not the result of developing anaemia during pregnancy, and such an increase is large enough to meet the increased requirements of pregnancy provided that the dietary intake is adequate.

Serial changes in serum uric acid concentrations have been studied in a group of healthy women before conception, at regular intervals throughout pregnancy and finally 12 weeks after delivery. Compared with pre-pregnancy values uric acid concentrations decreased significantly by 8 weeks gestation and this reduced level was maintained until about 24 weeks. Thereafter the concentrations increased such that by term they were greater than the pre-pregnancy values in the majority of patients and remained elevated until a t least 12 weeks after delivery. If clinical management during the second half of pregnancy is to be based on increases in serum uric acid concentrations then such increases will have to be carefully interpreted against the background of rising concentrations which occur as part of the physiological response t o normal pregnancy.Modern clinicians rely increasingly on laboratory tests for the management of patients; for some the stage has been reached when deviation from an accepted range of laboratory values is in itself sufficient reason to justify treatment. The principle is not intrinsically unreasonable but clinical management based solely, or even largely, on such tests implies a confidence in the 'normality' of any given range of laboratory values that is seldom justified.During pregnancy progressive maternal physiological adaptations occur and many biochemical measurements deviate conspicuously from the normal range for males and nonpregnant females. Laboratory ranges specific to pregnancy need to be defined and ideally would be determined in healthy women having uncomplicated pregnancies resulting in the birth of live healthy children; such data are relatively scarce.This paper describes the changes in serum uric acid concentrations throughout normal pregnancy and reports two clinically important aspects. First the values decrease significantly below non-pregnant levels by 8 weeks gestation; second serum uric acid concentrations are not only increased above non-pregnant values by term in many women but remain elevated for as long as 12 weeks after delivery. Such postpartum values should not therefore be used as representative of non-pregnant concentrations. Patients and methods PatientsThirty-one healthy women have been studied; the mean age was 28 (range 23-37) years and each was without any adverse medical, surgical or obstetric history. In five of the women uric acid determinations were repeated during a subsequent pregnancy so that data were obtained from a total of 36 pregnancies. Nine women were primigravidae and 27 were multiparae of whom five had had a previous spontaneous abortion and 22 a successful pregnancy. During the time of this study none of the patients developed medical or obstetric complications or required pharmacological agents including salicylates; all gave birth to live, healthy infants. 128

Summary Nineteen healthy pregnant women with no family history of diabetes took part in a serial study in which they had a standard 50 g. oral glucose tolerance test (OGTT) at 10, 20, 30 and 38 weeks gestation and again 10 to 12 weeks after delivery. While every test result remained within “normal” limits as defined by any of the standard criteria, subtle and progressive changes in the shape of the glucose response curve were shown to occur throughout pregnancy. These changes in shape were evaluated by means of the H index recently described by Billewicz et al. (1973); in 14 patients the values attained were characteristic of a “suspect” or “abnormal” response in non–pregnant subjects. Nevertheless since all of these women remained clinically normal throughout, and it is unlikely that 14 out of 19 will become diabetic later in life, it seems unreasonable that these changes per se should be regarded as evidence of impending pathology.

No abstract