Low serum zinc concentrations in pregnancy, results of investigations and treatment.

Twenty gravidae in whom the serum zinc concentration was less than 11.5 mumol/1 were investigated. Haemoglobin, serum vitamin B-12, serum folate, serum copper, and bone marrow smears were assessed. Thirteen showed haemoglobin concentrations below 110 g/1 and in 7 of them the cause of this anaemia was not found. Histological investigations indicated increased intramedullary cell destruction. Eight women selected at random were referred for further investigation including tests of renal and hepatic function, serum protein analyses, tests of haemolysis, and estimation of zinc and oestriol excretion in urine. The low serum zinc concentrations received no probable explanation other than zinc deficiency. Seven gravidae were treated with 90 mg Zn2+ daily as zinc sulphate by mouth during the latter part of pregnancy. Zinc excretion in urine was low and increased significantly (p less than 0.005) after one week's therapy. The serum zinc also increased (p less than 0.05). Zinc therapy gave no reticulocytosis within 8-12 days. Three women reported spontaneously an improvement in sense of taste. Five of 20 gravidae had dysmature infants. Heavy bleeding occurred at delivery in 6 cases, possibly secondary to impaired uterine contractility. Seven women who received zinc therapy had all normal deliveries, but labour was prolonged in one. No side effects of zinc therapy were noted except for nausea in one case. Further trials of zinc supplementation in larger series of women with low serum zinc concentrations during pregnancy seem to be justified.