Sharon F. Evans

Effects of frequent ultrasound during pregnancy : a randomised controlled trial

Despite widespread application of ultrasound imaging and Doppler blood flow studies, the effects of their frequent and repeated use in pregnancy have not been evaluated in controlled trials. From 2834 women with single pregnancies at 16-20 weeks gestation, 1415 were selected at random to receive ultrasound imaging and continuous-wave Doppler flow studies at 18, 24, 28, 34, and 38 weeks gestation (the intensive group) and 1419 to receive single ultrasound imaging at 18 weeks (the regular group). Outcome data was obtained from 99% of women who entered the study. The only difference between the two groups was significantly higher intrauterine growth restriction in the intensive group, when expressed both as birthweight < 10th centile (relative risk 1.35; 95% confidence interval 1.09 to 1.67; p = 0.006) and birthweight < 3rd centile (relative risk 1.65; 95% confidence intervals 1.09 to 2.49; p = 0.020). While it is possible that this finding was a chance effect, it is also plausible that frequent exposure to ultrasound may have influenced fetal growth. Repeated prenatal ultrasound imaging and Doppler flow examinations should be restricted to those women to whom the information is likely to be of clinical benefit.

Maternal cigarette smoking during pregnancy, low birth weight and subsequent blood pressure in early childhood

Given the widely acknowledged inverse relationship between birth weight and blood pressure, a raised blood pressure in the offspring of smoking mothers as compared to those whose mothers did not smoke, would be anticipated by virtue of the reduction in birth weight associated with smoking during pregnancy. The objective of the present study was to test the hypothesis that maternal cigarette smoking during pregnancy has an effect on blood pressure in childhood independent of its effect on birth weight. Data was obtained from a prospective cohort study of 1708 pregnant women and their singleton offspring, delivered live at term, in Perth, Western Australia, commenced at 16 weeks gestation with serial blood pressure measurements through early childhood. Statistically significant associations were found between maternal smoking during pregnancy and systolic blood pressure at age six, between birth weight and systolic blood pressure at ages three and six, and between maternal smoking during pregnancy and birth weight. The relationship between birth weight and blood pressure in early childhood differed significantly on the basis of maternal cigarette smoking or not during pregnancy. This differential relationship persisted after adjustment for the childs current weight and socio-economic status. We concluded that intra-uterine exposure to maternal cigarette smoking increased childrens blood pressure at age one through to age six. This was not wholly attributable to an effect on birth weight or confounding of the association between birth weight and subsequent blood pressure by the childs current weight or socio-economic factors. Furthermore, maternal smoking during pregnancy does not account for the acknowledged elevation in blood pressure associated with low birth weight. The present study is an exploration of a possible causal pathway underlying the birth weight/blood pressure association rather than simply a confirmation of such an association which has been detailed in many other papers.

Hospital admissions in the first year of life in very preterm infants

Objective: To analyse hospital readmissions to 1 year in infants <33 weeks’ gestation.

Recurrent wheezing in very preterm infants.

AIMS: To document the prevalence of, and identify risk factors for, recurrent wheezing treated with bronchodilators in the first year of life. METHODS: Parental history and neonatal data were collected prospectively in a regional cohort of very preterm infants (< 33 weeks). Data on maternal smoking, siblings at home, breast feeding, respiratory symptoms, and hospital re-admissions were documented at 12 months. RESULTS: Outcome data were available for 525/560 (95%) of survivors. The incidence of recurrent wheeze was 76/525 (14.5%) in very preterm infants and 20/657 (3%) in a cohort of term newborns. Significant risk factors for recurrent wheeze in very preterm infants were parental history of asthma, maternal smoking, siblings at home, neonatal oxygen supplementation at 28 days, 36, and 40 weeks of gestation. CONCLUSIONS: Wheezing respiratory illnesses are common in very preterm infants. The factors involved are similar to those in more mature infants, with the addition of immaturity and neonatal lung injury.

Morphine increases synchronous ventilation in preterm infants.

Objectives: To examine the short‐term cardiorespiratory effects of intravenous morphine infusion in ventilated preterm infants.

Characterisation of the possible effect on birthweight following frequent prenatal ultrasound examinations

The objective of this study was to evaluate and characterise by study of newborn biometry a possible effect on birthweight which we observed previously in a randomised controlled trial of multiple prenatal ultrasound examinations. A total of 2743 women with single pregnancies had been allocated at random to either a protocol of ultrasound imaging and continuous wave Doppler studies at 18, 24, 28, 34 and 38 weeks gestation (intensive group), or to a protocol of a single imaging examination at 18 weeks and further imaging scans only as clinically indicated (regular group). When compared with those in the regular group, and adjusted for other confounding variables, normally formed babies of term gestational age in the intensive group tended to be shorter when measured at birth (P = 0.123) and on day 2-3 of age (P = 0.068). There were statistically insignificant reductions in the circumferences of the chest, abdomen and mid-arm; and in the skinfold thicknesses of the triceps, parascapular and subscapular regions. Principal component analysis showed a trend for a reduction for the skeletal component (P = 0.085) but not for the soft tissue component (P = 0.332). Comparison of the neonatal biometry in the two groups is not conclusive, but the differential effects on the various growth parameters suggest that if multiple scans do indeed restrict fetal growth, the mechanism is more likely to be an effect on bone growth rather than a reduction in nutrient supply from the placenta.

Effect of an extended midwifery postnatal support programme on the duration of breast feeding: A randomised controlled trial

OBJECTIVEnto evaluate the effects of an extended midwifery support (EMS) programme on the proportion of women who breast feed fully to six months.nnnDESIGNnrandomised controlled trial.nnnSETTINGnlarge public teaching hospital in Australia.nnnPARTICIPANTSn849 women who had given birth to a healthy, term, singleton baby and who wished to breast feed.nnnINTERVENTIONnparticipants were allocated at random to EMS, in which they were offered a one-to-one postnatal educational session and weekly home visits with additional telephone contact by a midwife until their baby was six weeks old; or standard postnatal midwifery support (SMS). Participants were stratified for parity and tertiary education.nnnMEASUREMENTSnthe main outcome measures were prevalence of full and any breast feeding at six months postpartum.nnnFINDINGSnthere was no difference between the groups at six months postpartum for either full breast feeding [EMS 43.3% versus SMS 42.5%, relative risk (RR) 1.02, 95% confidence interval (CI) 0.87-1.19] or any breast feeding (EMS 63.9% versus SMS 67.9%, RR 0.94, 95%CI 0.85-1.04).nnnCONCLUSIONSnthe EMS programme did not succeed in improving breast-feeding rates in a setting where there was high initiation of breast feeding. Breast-feeding rates were high but still fell short of national goals.nnnIMPLICATIONS FOR PRACTICEncontinuing research of programmes designed to promote breast feeding is required in view of the advantages of breast feeding for all mothers and babies.

C-reactive protein as a diagnostic tool of sepsis in very immature babies

Abstract Three hundred and nine septic screens were performed on 123 consecutively admitted infants of <30 weeks gestation. As part of the septic screen, serial quantitative measurements of C‐reactive protein (CRP) were performed daily until discontinuation of antibiotic therapy. Complete blood counts were performed daily for the first 2 days of each septic episode.

Fetal Growth Retardation, Particularly within Lymphoid Organs, following Repeated Maternal Injections of Betamethasone in Sheep*

Objective: To examine the effect of single or repeated injections of maternally administered corticosteroids on fetal growth in sheep.

LOW DOSE ASPIRIN FOR THE TREATMENT OF FETAL GROWTH RESTRICTION : A RANDOMIZED CONTROLLED TRIAL

Summary: The purpose of this study was to investigate the hypothesis that maternal administration of lOOmg aspirin each day will improve birth‐weight and other measures of neonatal size when given as a treatment to pregnancies complicated by fetal growth restriction and umbilical‐placental insufficiency. A randomized, double‐blind, placebo controlled study design was employed; 51 pregnant women were enrolled. The entry criteria were a fetal abdominal circumference <10th per centile together with an umbilical artery Doppler systolic/diastolic ratio >95th per centile between 28 and 36 weeksgestation. Compliance was assessed by serial measurement of maternal serum thromboxane B2 levels. The mean gestational age at enrolment was 32 weeks and at delivery was 36 weeks. There were no differences between the 2 groups in gestational age at birth; birth‐weight or birth‐weight ratio; circumferences of the head, chest or abdomen; skin fold thicknesses; or neonatal morbidity. Low dose aspirin therapy did not alter Doppler systolic/diastolic ratios. After 14 days therapy, mean thromboxane B2 levels fell more than 80% from baseline values; 10.5% of women did not demonstrate biochemical confirmation of aspirin ingestion, despite verbal confirmation of compliance. We conclude that low dose aspirin therapy is not of benefit in the treatment of pregnancies complicated by fetal growth restriction and umbilical‐placental insufficiency between 28 and 36 weeks gestation.