Biomedical subjects

J Boreham

Publications and source records attributed to J Boreham.

43 records · Page 3Linked to original sources

PubMed1980

Maternal serum alpha-fetoprotein and birth weight.

Maternal serum alpha-fetoprotein (AFP) levels between 16 and 18 weeks of pregnancy were studied in relation to birth weight among 4198 singleton pregnancies resulting in a liveborn or stillborn infant without a neural tube defect. The highest mean birth weight (3365 g) was found among infants born to women with AFP values in the range 0.50 to 0.74 times the normal median for the relevant week of gestation. As the AFP decreased from this level to less than 0.25 times the median, the birth weight decreased by 193 g and the proportion of infants weighing 2500 g or less increased from 4 per cent to 11 per cent. As the AFP level increased from 0.50 to 0.74 times the median to 3.0 times the median or greater, the birth weight decreased by 371 g and the proportion of infants weighing 2500 g or less increased from 4 to 22 per cent. The negative association was the more important of the two since the magnitude was greater and it affected 92 per cent of pregnancies. The positive association among women with low ARP levels was substantially reduced when the analysis was restricted to women who had spontaneous labours. It seems that this minor positive association arises mainly because women in whom gestation is over-estimated tend to have both a low AFP and, later, an apparently prolonged pregnancy leading to the elective delivery of an infant who is, in fact, born early.

Birth Weight↗

PubMed1980

Small biparietal diameter of fetuses with spina bifida: implications for antenatal screening.

The biparietal diameter of 20 fetuses with spina bifida was measured during pregnancy by ultrasound scanning, mainly in the second trimester. The mean result was 0.83 cm smaller than the value based on 186 unaffected pregnancies at the same gestational ages (P less than 0.001), suggesting that spina bifida fetuses are growth retarded. The practical consequence of this finding is that the routine use of ultrasound in pregnancy will increase the sensitivity of AFP screening for open spina bifida at 16 to 18 weeks gestation from 79 per cent as estimated by the UK Collaborative AFP Study to about 90 per cent or more.

Cephalometry↗

PubMed1980

Birth weight of infants with spina bifida cystica.

The mean birth weight of 189 singleton infants with spina bifida cystica (including 21 with encephalocele) was statistically significantly less than the mean birth weight of 3816 singleton infants without neural tube defects, 0.20 kg less among male infants and 0.24 kg less among female infants. Most, if not all, of this difference in birth weight was due to the spina bifida infants being light for their gestational age. The difference could not be explained by differences in parity or social class.

Birth Weight↗

PubMed1980

Inhaling habits among smokers of different types of cigarette.

Inhaling habits were studied in 1316 men who freely smoked their usual brands of cigarette. An index of inhaling was calculated for each person by dividing the estimated increase in carboxyhaemoglobin level from a standard number of cigarettes by the carbon monoxide yield of the cigarette smoked. Smokers of ventilated filter cigarettes inhaled 82% more than smokers of plain cigarettes (p less than 0.001) and those who smoked unventilated filter cigarettes inhaled 36% more (p less than 0.001). Cigarette consumption was similar among smokers of each type of cigarette. Assuming that the intake of tar and nicotine is proportional to the inhaling index, the intake in either group of filter cigarette smokers would have been less than that in plain cigarette smokers. Among smokers of unventilated cigarettes, however, the intake would not have been much less.

Adult↗

PubMed1979

Antenatal screening in Oxford for fetal neural tube defects.

Between May 1975 and the end of 1977, 6443 antenatal patients were screened mainly between 16 and 22 weeks of pregnancy for neural tube defects (NTDs) at the John Radcliffe Hospital, Oxford, by maternal serum alpha-fetoprotein (AFP) measurement; a take-up of 72 per cent. Seventeen out of 18 (94 per cent) patients with open NTD pregnancies (9 out of 9 with anencephaly and 8 out of 9 with open spina bifida) had positive screening tests, and all except one were offered and accepted a termination of pregnancy. Two hundred and forty-five (3.8 per cent) patients with unaffected pregnancies also had positive screening tests, although only 1.4 per cent had an amniocentesis. Following ultrasonography, about 50 per cent of patients with unaffected pregnancies with positive screening tests were not offered an amniocentesis because they had a multiple pregnancy or their gestational age had been underestimated. The odds of having a fetus with an NTD among the women who had an amniocentesis was about 1 to 6 (1 to 11 for open spina bifida alone). Two apparently normal pregnancies were terminated. A survey of the acceptability of the screening programme among a consecutive sample of 73 patients who knew that they had a positive screening test revealed that all except one had no objection to screening in general, and 68 (93 per cent) wanted to be tested again in a future pregnancy. The approximate direct cost of the programme was 2 pounds to 3 pounds per patient screened, or about 1000 pounds per NTD detected (about 2200 pounds per open spina bifida detected).

Amniocentesis↗

PubMed1979

Maternal serum alpha-fetoprotein and diabetes mellitus.

Maternal serum alpha-fetoprotein (AFP) levels were measured from 12 to 24 weeks gestation in 27 singleton pregnancies in women with insulin-dependent diabetes mellitus and 90 controls without diabetes who were matched for gestational age. The geometric mean AFP level among the diabetic pregnancies was 60 per cent of that in the controls, a difference which was statistically significant (P less than 0.01). The difference in AFP level between diabetic patients and controls was most marked in sera taken before 21 weeks gestation.

Adult↗

PubMedDate not supplied

A survey of diagnostic amniocenteses in Oxford from 1974-1981.

A survey was conducted of the results of mid-trimester diagnostic amniocenteses in the Oxford Region from 1974 to 1981. The survey used data relating to all 4357 singleton pregnancies in which an amniocentesis was performed during this period. Follow-up information on outcome was obtained in respect of 4284 (98 per cent) pregnancies. A cell culture to determine karyotype and an alpha-fetoprotein determination was carried out in all cases. From 1974 to 1981 amniocenteses became increasingly common, rising from 2 to 32 per 1000 births. The most common indication for amniocentesis was a high risk of a chromosome abnormality--56 per cent of all amniocenteses. Within this group advanced maternal age was responsible for 89 per cent of the cases. The next most common indication was a high risk of a neural tube defect (37 per cent of all amniocenteses) --in 1974 a raised maternal serum alpha-fetoprotein level accounted for only 4 per cent of these; by 1981 this had risen to 67 per cent. There were seven false-positive and 132 true-positive diagnoses of neural tube defect; since 1981, with the introduction of amniotic fluid acetylocholinesterase determination as a secondary diagnostic test for neural tube defects, there have been no further false-positive diagnoses. In 1981 76 per cent of women aged 35 years or more did not have an amniocentesis. It is not known to what extent this was due to not offering women in this age group amniocentesis or to women not accepting such an offer.

Abortion, Spontaneous↗