Differing effects of low and high bulk maternal dietary supplements during pregnancy.

The study attempted to determine if the bulk of dietary supplements given to pregnant women after midgestation affects fetal growth. 127 Zulu women were randomly assigned to four groups, two of which received daily food supplements designed to raise their energy, protein and vitamin intakes to levels recommended by the U.S. Food and Nutrition Board. One of these supplements had a high bulk, the other a low bulk. The third supplement contained only zinc and the fourth a placebo. Women in all four groups had a similar weight gain and length of gestation. Birth weights were from 6.5 to 9.5% greater with the low bulk than with the other supplements.

The effect of diet supplementation and addition of zinc in vitro on the growth-supporting property of amniotic fluid in African women.

The effect of diet supplementation throughout pregnancy on third-trimester amniotic fluid growth-supporting activity (GSP) was studied in 100 African women; 32 were given zinc supplementation, 22 each animal and vegetable supplements, respectively, and 24 served as control subjects. No difference in GSP was noted in any of the four groups, the majority of fluids (65%) being noninhibitory. Zinc levels in fluids from African women were much lower than those described for other population groups at corresponding periods of gestation. Although zinc levels in liquor rose following dietary zinc supplementation, these remained lower than values described in white patients. In vitro addition of zinc (up to 153 mu moles per liter final concentration) to 17 noninhibitory African liquors resulted in these fluids becoming inhibitory.

PIP: The effect of 3 diet supplementation regimes throughout the latter part of pregnancy on the growth-supporting property (GSP) of third trimester fluids was studied in 100 African women: 32 were given zinc, 22 each animal and vegetable supplements, respectively; and 24 were controls. No significant increase of inhibitory activity was found in any of the 4 groups, the majority of fluids (overall average 65%) being noninhibitory. Zinc levels were very low as compared with Caucasian women. The effect of in vitro addition of zinc on the GSP of 17 noninhibitory fluids from African women showed 5 fluids becoming bacteriostatic and 12 becoming bactericidal after adding zinc at a final concentration of 15.3 mcmol/l; raising levels 5 and 10 times those concentrations rendered all fluids bactericidal. Zinc alone did not affect the growth of Staphylococcus aureus in control subjects without liquor.

The genesis of amniotic fluid infections.

Amniotic fluid infections manifested by an inflammatory response in the extraplacental membranes and subchorionic plate of the placenta are a common phenomenon thought to be due in most cases to ascending bacterial infections via intact membranes. Fatal spread to the fetus is much less common and more likely to occur in underprivileged communities. The probable reasons are nutritional deprivation in the mother or both, leading to production of a liquor with diminished ability to suppress bacterial growth. Zinc is one component of the antibacterial system but liquor levels of zinc vary widely and inconsistently with antibacterial activity. Dietary supplementation with zinc did not improve antibacterial activity of liquors in a population with diminished liquor antibacterial activity and large number of fatal infections. Other factors in the genesis of amniotic fluid infections may be interference with normal defence mechanisms as a result of coitus in late pregnancy and vaginal infections with Trichomonas vaginalis. Socioeconomic factors may play a role apart from their association with maternal nutrition, through diminished hygiene associated with insufficient use of water and insufficient availability and use of medical facilities.