Prediction and prevention of small‐for‐gestational‐age neonates: evidence from SPREE and ASPRE

In a study to evaluate the reproducibility and accuracy of the sonar technique of measurement of the in vivo fetal crown-rump length (Robinson, 1973), a series of in vivo and in vitro experiments was performed in which the random and systematic errors inherent in the technique were assessed. The potential sources of random error were those of operator judgement, movement of the fetus and mother, machine sensitivity settings and measurement from the photograph; while the sources of systematic error were those of oscilloscope scale factor, and velocity calibration inaccuracies, and the effect of beam width. The overall effect of the random errors, that is, the reproducibility of the technique, was assessed in an in vivo blind trial in which three independent measurements were made of the fetus. In a series of 30 experiments the average standard deviation of the three readings was found to be 1.2 mm. Evaluation of the systematic errors by in vivo experimentation, on the other hand, showed that the basic sonar measurements were in error by an overestimate of 1 mm for the beam width effect and 3.7 per cent for the scale factor and velocity calibration errors. A weighted non-linear regression analysis of 334 measurements was performed in order to obtain a "curve of best fit" for the period covering 6 to 14 weeks of menstrual age. The values obtained were corrected for the systematic errors and compared with widely quoted anatomical figures. In the second part of this investigation the original data was further analyzed to determine on a statistical basis the accuracy of the technique as a method of estimating maturity. It was shown that such an estimate could be made to within 4.7 days with a 95 per cent probability on the basic of a single measurement, and to within 2.7 days if three independent measurements were made.

The increasing survival rates of children who are born very preterm raise issues about the risks of neurological disabilities and cognitive dysfunction. We aimed to investigate neurodevelopmental outcome and use of special health care at 5 years of age in a population-based cohort of very preterm children. We included all 2901 livebirths between 22 and 32 completed weeks of gestation from nine regions in France in Jan 1-Dec 31, 1997, and a reference group of 667 children from the same regions born at 39-40 weeks of gestation. At 5 years of age, children had a medical examination and a cognitive assessment with the Kaufman assessment battery for children (K-ABC), with scores on the mental processing composite (MPC) scale recorded. Data for health-care use were collected from parents. Severe disability was defined as non-ambulatory cerebral palsy, MPC score less than 55, or severe visual or hearing deficiency; moderate deficiency as cerebral palsy walking with aid or MPC score of 55-69; and minor disability as cerebral palsy walking without aid, MPC score of 70-84, or visual deficit (<3/10 for one eye). In total, 1817 (77%) of the 2357 surviving children born very preterm had a medical assessment at 5 years and 396 (60%) of 664 in the reference group. Cerebral palsy was diagnosed in 159 (9%) of children born very preterm. Scores for MPC were available for 1534 children born very preterm: 503 (32%) had an MPC score less than 85 and 182 (12%) had an MPC score less than 70. Of the 320 children in the reference group, the corresponding values were 37 (12%) and 11 (3%), respectively. In the very preterm group, 83 (5%) had severe disability, 155 (9%) moderate disability, and 398 (25%) minor disability. Disability was highest in children born at 24-28 completed weeks of gestation (195 children [49%]), but the absolute number of children with disabilities was higher for children born at 29-32 weeks (441 children [36%]). Special health-care resources were used by 188 (42%) of children born at 24-28 weeks and 424 (31%) born at 29-32 weeks, compared with only 63 (16%) of those born at 39-40 weeks. In children who are born very preterm, cognitive and neuromotor impairments at 5 years of age increase with decreasing gestational age. Many of these children need a high level of specialised care. Prevention of the learning disabilities associated with cognitive deficiencies in this group is an important goal for modern perinatal care for children who are born very preterm and for their families.