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Biomedical subjects

Philip Steer

Publications and source records attributed to Philip Steer.

7 recordsLinked to original sources
PubMed2005

The epidemiology of preterm labour.

Although the definition of preterm birth is birth before 37 completed weeks, the major transition in terms of needing special care occurs between 34 and 37 weeks. The Homo sapiens neonate is born much more immature than other anthropoid species, perhaps because earlier birth has evolved to avoid the large head of the human fetus becoming impacted in the small pelvis of the mother, who has become adapted to a bipedal gait. The main burden of preterm birth exists in developing countries. There are no accurate recent worldwide data, but estimates of preterm birth rates range from 5% in developed countries to 25% in developing countries. The preterm delivery rate has been relatively stable at 5-10% in developed countries for many years. The North Thames database of 517,381 pregnancies demonstrates significant ethnic variation in preterm birth rates, with higher rates in black women. This is associated with an accelerated rate of maturity in the black fetus and neonate, with correspondingly lower gestation-specific neonatal mortality rates below 38 weeks, and higher at 38 weeks of gestation and beyond. Ethnic differences can explain only a very small proportion of global preterm births. The greatest aetiological factor worldwide is infection, mainly due to malaria and HIV. In developed countries, iatrogenic delivery is responsible for almost half of the births between 28 and 35 weeks; hypertension and pre-eclampsia are the major pathologies. Other factors include multiple pregnancy, intrauterine growth restriction, maternal stress and heavy physical work.

Female↗
PubMed2005

The bioethics of preterm labour.

Until recently, bioethics (ethics related to biology or, more specifically, in the context of preterm labour, medical ethics) was considered mainly to relate to the active treatment or investigation of patients. Collection of data, excised specimens or even whole organs was considered to be relatively uncontentious as it did not impinge directly upon the health of the individual concerned. However, in the UK in particular, the practice of collecting data, tissues or even whole organs has recently come under the spotlight of public scrutiny, particularly following the Alder Hey Enquiry. Coincidentally with a decline in public confidence in the probity of authority, medical scientists increasingly have to justify the accumulation of data about individuals.

Adrenal Cortex Hormones↗
PubMed2005

The epidemiology of preterm labor--a global perspective.

The major burden of preterm birth is in the developing world, where much of the death and morbidity is secondary to infectious diseases such as malaria, HIV, tuberculosis and intestinal parasites. There is some evidence to support the concept that normal gestational length varies with ethnic group; babies of black African ancestry tend to be born earlier, more commonly pass meconium in labor, but have less respiratory distress than white European babies of matched gestational age. However, ethnic differences are tiny compared with the effects of infectious disease and malnutrition. Interventions to prevent preterm birth should predominantly be aimed at the prevention and treatment of infectious disease, and the improvement of maternal nutrition. Without this, medical intervention tends to increase the rate of preterm birth without corresponding improvement in outcomes.

Developing Countries↗
PubMed2004

The management of large and small for gestational age fetuses.

The major influence on birth weight is gestational age. At any given week of gestation, however, size varies enormously. There is no specific cut-off that separates abnormally large or small babies for gestational age from normal. Instead, function alters as a continuum across the weight distribution. Small babies are prone to hypoxia, acidosis, and stillbirth. Large babies on the other hand are associated with prolonged labor and mechanical problems. The optimum size for fetal survival is 1 to 1.5 standard deviations above the mean, whereas cesarean section rates are lowest when the fetal weight is 0.5 to 1.5 standard deviations below the mean. Antenatal detection of both very small and very large babies is difficult and imprecise. Expectant management is therefore preferable unless there are very specific indications for emergency or operative delivery.

Cesarean Section↗
PubMed2004

Does gestation vary by ethnic group? A London-based study of over 122,000 pregnancies with spontaneous onset of labour.

BACKGROUND: Evidence exists that normal gestational length varies with ethnicity. This UK-based study compares gestational length amongst a cohort of white European, Black and Asian women. METHODS: The cohort comprised 122 415 nulliparous women with singleton live fetuses at the time of spontaneous labour, giving birth in the former North West Thames Health Region, London, UK. RESULTS: The median gestational age at delivery was 39 weeks in Blacks and Asians and 40 weeks in white Europeans. Black women with normal body mass index (BMI) (18.5-24.9 kg/m(2)) had increased odds of preterm delivery (odds ratio [OR] = 1.33, 95% CI: 1.15, 1.56, adjusted for deprivation and BMI) compared with white Europeans. The OR of preterm delivery was also increased in Asians compared with white Europeans (OR = 1.45, 95% CI: 1.33, 1.56, adjusted for single unsupported status and smoking). Meconium stained amniotic fluid, which is a sign of fetal maturity, was statistically significantly more frequent in preterm Black and Asian infants and term Black infants compared with white European infants. CONCLUSIONS: This research suggests that normal gestational length is shorter in Black and Asian women compared with white European women and that fetal maturation may occur earlier.

Adolescent↗