No abstract

The Hb level during pregnancy was followed in 113 non-anaemic women with uncomplicated pregnancy and birth weight of the baby above the 2.5th percentile. There was an inverse correlation close to statistical significance between the birth weight of the baby and the lowest Hb level reached during pregnancy as well as the Hb level in late pregnancy (38th week). A group of seven non-anaemic women with birth weight of the baby below the 2.5th percentile had a significantly higher (p less than 0.001) Hb level in late pregnancy than the normal group. Four of these cases had a statistically significant higher Hb level already in the second trimester. Trends in the reproductive history, complaints in the present pregnancy as well as results of hormone assays and the condition of the baby indicated that the seven cases represented a pathological group with fetal growth retardation. None of the women in the two groups were treated with diuretics. All had iron supplementation in high doses.

In a series of 24 apparently uncomplicated pregnancies with small-for-dates newborn at or below the tenth percentile, 15 women had hemoglobin (Hb) levels 2 SD above the mean value of normal distribution in late pregnancy. Among these 15 was the only case with intrauterine death of unknown cause. In a series of 15 cases intrauterine fetal death of unknown cause, before start of labor 10 had Hb levels 2 SD above the mean, while in a series of 16 cases of late abortion where the fetus was alive until labor started, only one had a Hb level 2 SD above the mean. In three cases with serial Hb estimations, the levels were 2 SD above the mean one week or more before intrauterine fetal death. Two of these cases also had been observed during a successful pregnancy in which the Hb levels were within normal limits. It is concluded that high Hb levels during pregnancy may indicate a fetus at risk. High viscosity of the mother's blood may impede the uteroplacental circulation, casing placental infarction, growth retardation and ultimately fetal death.

Summary. The last maternal haemoglobin (Hb) concentration before delivery was related to the perinatal outcome in 87 non‐anaemic women suffering from severe pre‐eclampsia. Abnormally high Hb concentrations were found in most women with evidence of placental dysfunction. An inverse correlation was found between the centile weight of the newborn and the maternal Hb. Significantly higher Hb levels were found in pregnancies complicated by fetal growth retardation and perinatal distress compared with those in pregnancies with good outcomes. Particularly high levels were found in pregnancies that ended in perinatal deaths. The hypothesis is put forward that raised haemoconcentration during severe pre‐eclampsia causes increased maternal blood viscosity which predisposes to placental pathology and initiates a vicious circle.

The last maternal haemoglobin (Hb) concentration before delivery was related to the perinatal outcome in 87 non-anaemic women suffering from severe pre-eclampsia. Abnormally high Hb concentrations were found in most women with evidence of placental dysfunction. An inverse correlation was found between the centile weight of the newborn and the maternal Hb. Significantly higher Hb levels were found in pregnancies complicated by fetal growth retardation and perinatal distress compared with those in pregnancies with good outcomes. Particularly high levels were found in pregnancies that ended in perinatal deaths. The hypothesis is put forward that raised haemoconcentration during severe preeclampsia causes increased maternal blood viscosity which predisposes to placental pathology and initiates a vicious circle. Gibson, H. M. (1973) Plasma volume and glomerular 927-936.