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Biomedical subjects

R L Naeye

Publications and source records attributed to R L Naeye.

At least 55 records · Page 3Linked to original sources
PubMed1982

Causes of fetal and neonatal mortality in a South African black community.

Little has been published about the underlying disorders responsible for the high perinatal mortality rates found in African cities. We searched for answers by identifying the causes of fetal and neonatal death in Blacks living in and around Durban. A 91% autopsy rate was achieved when 506 postmortem examinations were performed in 557 consecutive cases of fetal and early neonatal death. The perinatal mortality rates were 55/1000 for single births and 170/1000 for twins; 29% of the deaths were due to amniotic fluid infections, 9% to abruptio placentae, 5% to birth trauma, 4% to congenital syphilis, 4% to obstructed labour, 4% to major congenital malformations, 2% to umbilical cord compression and the rest to more than 20 other specific disorders.

Africa, Northern↗
PubMed1982

Coitus and chorioamnionitis: a prospective study.

Amniotic fluid infections have been strongly associated with coitus during pregnancy. If the relationship is causal it may be possible to identify a time sequence between coitus, penetration of bacteria through the mucous plug in the cervix, the development of infection in the extraplacental membranes near the cervical os, spread of the infection to the amniotic fluid and complications of the infection. The present study looked for such a sequence in an analysis of 541 pregnancies. A peak frequency of chorioamnionitis limited to the extraplacental membranes was present when labor and delivery took place within two days of the last coitus. In the next two days the infection spread to the amniotic fluid as evidenced by a peak frequency of maternal neutrophils migrating through the placental plate toward the amniotic cavity. Premature delivery was 4 times more frequent when there had been recent coitus and an amniotic fluid infection was present than when either factor was absent (P less than 0.01). Spontaneous rupture of the fetal membranes before the onset of and the membranes were inflamed than when these factors were absent (P less than 0.01). This raises the possibility that orgasm further weakened or ruptured membranes that had already been weakened by infection.

Amnion↗
PubMed1982

Working during pregnancy: effects on the fetus.

In order to determine whether pregnancy outcome was altered when women were employed outside their homes, 7,722 pregnancies were analyzed. Gestations were not shortened but newborns of women who worked in the third trimester weighed 150 to 400 gm less than newborns of mothers who remained at home. The growth retardation was greatest when women were underweight pregravid and had a low pregnancy weight gain, when they were hypertensive, or when the work required standing. The growth retardation remained after the data were stratified by race, socioeconomic status, and other maternal factors that commonly influence fetal growth. The frequency of large placental infarcts progressively increased when women continued stand-up work into late gestation. Such infarcts reached a peak of 250/1,000 births after the 37th week of gestation in stand-up workers. Low uteroplacental blood flow is a likely explanation for both the fetal growth retardation and the large placental infarcts.

Birth Weight↗
PubMed1982

Factors that predispose to premature rupture of the fetal membranes.

Causes of premature rupture of the fetal membranes were explored in a study of 10,460 pregnancies. Five risk factors were analyzed: Cigarette smoking, coitus, parity, prior surgery of the cervix, and chorioamnionitis. To minimize the effects of other influences the author compared the rates of premature rupture in successive pregnancies of the same mothers when the individual risk factors being analyzed were present in only 1 of the 2 pregnancies. Preterm delivery due to premature rupture of the membranes was 11 times more frequent when recent coitus was present in conjunction with chorioamnionitis than when both were absent. Such ruptures were increased only 3-fold when either recent coitus or chorioamnionitis was present without the other.

Amnion↗
PubMed1981

Maternal blood pressure and fetal growth.

Eleven thousand eighty-two term, singleton pregnancies were analyzed for clues to how different levels of maternal blood pressure affect fetal growth. Birth weights progressively increased with increasing pressures until the hypertensive range was reached when maternal edema and proteinuria were absent. Pressure-associated increases in fetal growth were even more rapid when mothers were edematous, and slower when 2+ or greater proteinuria was present. Birth weights leveled off or decreased when pressures reached the hypertensive range. The pressure threshold at which growth slowed increased from diastolic 75 mm Hg in the lowest maternal pregnancy weight gain category to nearly 100 mm Hg in the highest weight gain category. Decreases in birth weight associated with hypertension were most severe when mothers were thin and had low pregnancy weight gains. Diuretics reduced birth weights in low maternal weight gain pregnancies but not in high weight gain ones.

Birth Weight↗
PubMed1981

Effects of maternal acetonuria and low pregnancy weight gain on children's psychomotor development.

Data were analyzed from a large prospective study to determine if children had an excess of psychomotor or IQ impairment when their mothers had eight acetonuria, weight loss, or low weight gain during pregnancy. The effects of these maternal factors on children's development were assessed by a variety of mental and motor tests from the newborn period to 7 years of age. No consistent impairments were found at any age.

Body Weight↗
PubMed1981

Coitus and antepartum haemorrhage.

The relationship of coitus to antepartum haemorrhage was explored in a longitudinal study of 56 568 pregnancies. The frequency of the haemorrhages was 19/1000 births when women reported no recent coitus compared with 30/1000 when there had been recent coitus (p less than 0.001). The frequency of the bleeding increased with the frequency of coitus. The correlation between coitus and bleeding was independent of other factors known to increase the risk of antepartum bleeding including cigarette smoking, hypertension, advancing maternal age and placenta praevia.

Coitus↗
PubMed1981

Teenaged and pre-teenaged pregnancies: consequences of the fetal-maternal competition for nutrients.

The study attempted to determine whether the growth needs of young mothers compete with the growth needs of their fetuses for available nutrients. In a large prospective study, 10- to 16-year-old mothers had significant smaller newborns at term than older mothers when the various maternal age groups were matched for prepregnancy body size and pregnancy weight gain. Five percent of the urines of 10- to 14-year-old mothers had 2+ or greater acetone vs only 2% of the urines of 17- to 32-year-old mothers (P less than .001). Acetonuria has been shown to be a marker for high perinatal mortality in undernourished gestations, and it correlated with a high perinatal mortality in the present study. The growth retardation found in the newborns of very young mothers disappeared during childhood.

Acetone↗
PubMed1981

Racial and environmental influences on fetal lung maturation.

Claims that fetal lung maturation is more rapid in blacks than in whites were investigated. Histologic measurements of lung maturation and the frequency of hyaline membrane disease were compared in four groups of Neonates: 490 South African blacks, 841 Ethiopians, 767 US blacks, and 560 US whites. Lungs matured much more rapidly in the Ethiopian and more slowly in the South African than in the US fetuses. The rate of maturation was about the same in the US blacks and whites. Hyaline membrane disease was more frequent in the South Africans and less frequent in the Ethiopians than in either US group. Environmental factors in the mother may explain some of these differences. Lungs matured more rapidly in the fetuses of cigarette smokers than in fetuses of nonsmokers. Half of the US mothers but almost none of the South African mothers smoked during pregnancy. The rate of lung maturation had an inverse correlation with maternal body weights. The South African women were heavier and the Ethiopians lighter than women in the United States.

Birth Weight↗
PubMed1981

Influence of maternal cigarette smoking during pregnancy on fetal and childhood growth.

Data from 8193 pregnancies were analyzed for clues to the mechanisms responsible for the fetal growth retardation associated with maternal cigarette smoking. The retardation proved independent of mothers' prepregnancy body weights and pregnancy weight gains; therefore, it was not due to undernutrition. As the retardation was present in intrapair comparisons of siblings whose mothers had smoked in only 1 of their pregnancies, it was not due to genetic factors. Cigarette smoking causes permanent damage to uterine arteries; however, this did not retard fetal growth because retardation was absent when mothers stopped smoking during pregnancy. Results of the study exclude undernutrition, genetic factors, and placental underperfusion as major contributing factors to the fetal growth retardation associated with cigarette smoking.

Birth Order↗
PubMed1980

Studies on the growth-inhibiting property of amniotic fluids from two United States population groups.

This study attempted to determine if lack of antimicrobial activity in amniotic fluid is the reason United States blacks have more amniotic fluid bacterial infection than whites. No significant interracial differences were found in a study of 111 fluids from whites and 56 fluids from blacks. It has been claimed that the phosphate:zinc ratio in amniotic fluid is an accurate predictor of antimicrobial activity. The present study found this often to be untrue. Amniotic fluids that lacked antimicrobial activity gained such activity when zinc was added, but the in vitro zinc levels required were usually higher than observed physiologic concentrations. Previous studies have claimed that antimicrobial activity first appears in the amniotic fluid in the third trimester of gestation. We found such activity in the majority of fluids by the end of the first trimester, with a Staphylococcus aureus indicator; in contrast, with Escherichia coli and Streptococcus agalactiae as test organisms, greater inhibition was observed after 35 weeks.

Amniotic Fluid↗
PubMed1980

Causes and consequences of premature rupture of fetal membranes.

Data from 6613 pregnancies that ended before term were analysed to determine whether amniotic-fluid infections are a cause as well as a consequence of premature rupture of the fetal membranes. Amniotic-fluid infections seem to be a cause of such ruptures because the infections were 2-3 fold more common when the fetal membranes ruptured just before labour started than when they ruptured just after the onset of labour. There was no relation between the frequency of premature rupture and the number of coital acts in the month before delivery but at every gestational age the proportion of fetuses and neonates who died with amniotic-fluid infections was greater when coitus had occurred in the month before delivery. This was because the infections associated with coitus were more severe. Low Apgar scores and neonatal hyperbilirubinaemia were 60% more frequent when preterm delivery was due to premature rupture of the membranes than when it was due to other causes. This was mainly the result of the high frequency of amniotic-fluid infections associated with the premature membrane ruptures.

Amniotic Fluid↗