Leiv S. Bakketeig

WHO antenatal care randomised trial for the evaluation of a new model of routine antenatal care

BACKGROUND We undertook a multicentre randomised controlled trial that compared the standard model of antenatal care with a new model that emphasises actions known to be effective in improving maternal or neonatal outcomes and has fewer clinic visits. METHODS Clinics in Argentina, Cuba, Saudi Arabia, and Thailand were randomly allocated to provide either the new model (27 clinics) or the standard model currently in use (26 clinics). All women presenting for antenatal care at these clinics over an average of 18 months were enrolled. Women enrolled in clinics offering the new model were classified on the basis of history of obstetric and clinical conditions. Those who did not require further specific assessment or treatment were offered the basic component of the new model, and those deemed at higher risk received the usual care for their conditions; however, all were included in the new-model group for the analyses, which were by intention to treat. The primary outcomes were low birthweight (<2500 g), pre-eclampsia/eclampsia, severe postpartum anaemia (<90 g/L haemoglobin), and treated urinary-tract infection. There was an assessment of quality of care and an economic evaluation. FINDINGS Women attending clinics assigned the new model (n=12568) had a median of five visits compared with eight within the standard model (n=11958). More women in the new model than in the standard model were referred to higher levels of care (13.4% vs 7.3%), but rates of hospital admission, diagnosis, and length of stay were similar. The groups had similar rates of low birthweight (new model 7.68% vs standard model 7.14%; stratified rate difference 0.96 [95% CI -0.01 to 1.92]), postpartum anaemia (7.59% vs 8.67%; 0.32), and urinary-tract infection (5.95% vs 7.41%; -0.42 [-1.65 to 0.80]). For pre-eclampsia/eclampsia the rate was slightly higher in the new model (1.69% vs 1.38%; 0.21 [-0.25 to 0.67]). Adjustment by several confounding variables did not modify this pattern. There were negligible differences between groups for several secondary outcomes. Women and providers in both groups were, in general, satisfied with the care received, although some women assigned the new model expressed concern about the timing of visits. There was no cost increase, and in some settings the new model decreased cost. INTERPRETATIONS Provision of routine antenatal care by the new model seems not to affect maternal and perinatal outcomes. It could be implemented without major resistance from women and providers and may reduce cost.

Birthweight by gestational age in Norway

Objective. To describe birthweight by gestational age in Norway for the period 1967–1998, evaluate secular trends and provide new standards for small for gestational age for 16 to 44 weeks of gestation.

Pre- and post-natal growth in children of women who smoked in pregnancy.

Pre- and post-natal growth was studied from week 17 of pregnancy until 5 years of age in children of women who reported daily smoking at the time of conception, and compared to the growth in children of non-smokers. Fetal abdominal diameter, femur length and biparietal diameter were measured in weeks 17 and 37 of pregnancy, and weight, height and head circumference were measured at birth, and at 6, 13 and 60 months of age in 185 children of smokers and 345 children of non-smokers. Cross sectional data at birth showed that infants of smokers had lower weight and length, but similar ponderal index as infants of non-smokers and this may suggest a symmetrical growth retardation. Longitudinal growth curves indicated that the growth retardation took place in the second half of pregnancy. During the first 5 years of life, children of smokers had complete catch-up growth in weight, a partial catch-up in height, and no catch-up growth in head circumference. At 5 years, children of smokers had a higher ponderal index and skinfold thickness, suggesting that these children, on average, were more obese than children of non-smokers.

Cluster headache prevalence. Vågå study of headache epidemiology

In the Vågå study of headache epidemiology, a search was made also for cluster headache. Of the available 18-65-year-old dalesmen, 1838 (88.6%) could be examined personally (O.S.) – 51.3% females and 48.7% males. Based on current International Headache Society criteria, cluster headache seemed to be present in seven dalesmen, one female and six males (corresponding to a total prevalence of 381 per 100 000; 95% confidence interval (CI) 153-783 per 100 000). Except for the female gender, the female case was fairly typical. In one case, there were short-lasting bouts (‘minibouts’). It was felt that this also was a genuine case of cluster headache. If one excluded the latter case, there would be one female and five males [a prevalence of 106 per 100 000 for females, and 558 per 100 000 for males, giving a prevalence in the total population of 326 per 100 000 (95% CI 120-709 per 100 000)]. The confidence interval was considerable. This study therefore does not give a clear indication as to prevalence.

Pre-pregnancy risk factors of small-for-gestational age births among parous women in Scandinavia

To study the etiology and consequences of intrauterine growth retardation (IUGR), a prospective study was organized by the National Institute of Child Health and Human Development, NIH, with the Universities of Trondheim and Bergen in Norway, Uppsala in Sweden, and Alabama in the United States. This paper reports on the Scandinavian portion of the study. 6,354 women were referred to the study and 5,722 women, who were expecting their second or third child between January 1986 and March 1988, were eligible and made their first appointment for the study. Of these, 1,945 women and their births were selected for follow‐up at four prenatal visits, delivery, and during the first year of life. This report analyzes the relative impact of various maternal pre‐pregnancy risk factors associated with SGA birth. For example, mothers who smoked cigarettes around the time of conception, but who had none of the other major risk factors, nearly doubled their risk of SGA birth. A previous low birth weight (LBW) delivery increased the risk nearly two and a half times among non‐smokers. If a mother both smoked and had a previous LBW, the relative risk rose to nearly five and a half. Low maternal pre‐pregnancy weight (> 50 kg) increased the risk of SGA birth almost twofold among non‐smokers, while low pre‐pregnancy weight and smoking together increased the risk of SGA birth fourfold. A low weight mother who smoked and also had a previous LBW delivery, had a risk of SGA birth that was nearly six times that of a mother without those characteristics.

Gynaecological impact of sexual and physical abuse by spouse. A study of a random sample of Norwegian women

A sample of 150 women aged between 20 and 49 was randomly selected from the census of the city of Trondheim, Norway. Of the 131 eligible for the study, 13 refused to participate; the participating 118 women were interviewed by a gynaecologist. Detailed information about their present and previous spouse(s) and about sexual problems and gynaecological symptoms was obtained. Physical abuse by spouse had occurred in 20 (18%) of the 111 women who had ever lived in a relationship, and sexual abuse in 19 (17%). Eleven (10%) had experienced both physical and sexual abuse. A history of physical abuse with or without sexual abuse by spouse was associated with sexual problems in the present or in previous relationships. Reported abuse by spouse was also associated with a higher frequency of gynaecological symptoms at the time of interview.

Cognitive development of term small for gestational age children at five years of age

AIM To assess the relative significance for cognitive development of small for gestational age, parental demographic factors, and factors related to the child rearing environment. METHODS IQ of a population based cohort of 338 term infants who were small for gestational age (SGA) and without major handicap, and a random control sample of 335 appropriate for gestational age (AGA) infants were compared at 5 years of age. RESULTS The mean non-verbal IQ was four points lower, while the mean verbal IQ was three points lower for the children in the SGA group. The results were not confounded by parental demographic or child rearing factors. However, parental factors, including maternal non-verbal problem solving abilities, and child rearing style, accounted for 20% of the variance in non-verbal IQ, while SGA versus AGA status accounted for only 2%. The comparable numbers for verbal IQ were 30 and 1%. Furthermore, we found no evidence that the cognitive development of SGA children was more sensitive to a non-optimal child rearing environment than that of AGA children. Maternal smoking at conception was associated with a reduction in mean IQ comparable to that found for SGA status, and this effect was the same for SGA and AGA children. The cognitive function of asymmetric SGA was comparable to that of symmetric SGA children. CONCLUSIONS Our findings indicate that child cognitive development is strongly associated with parental factors, but only marginally associated with intrauterine growth retardation.

Risk factors associated with the occurrence of preterm birth.

Epidemiologic studies have demonstrated associations between preterm birth and several biologic, behavioral, and social factors. However, preterm birth as a phenomenon has not changed very much over time, and the differences between populations are not as great as one would expect, if one takes into account the vast differences in the occurrence of the known risk factors. The implication is that knowledge about some of the most significant risk variables is still lacking. Hence, there is a need to collect more detailed information, particularly on behavioral and social variables, which may indicate new risk factors. In addition, well-designed intervention studies may provide new insights into cause-and-effect relationships with regard to preterm birth. A number of such studies have recently been designed and have begun collecting data. An increased understanding of the etiology of preterm birth will undoubtedly result from these clinical trials and related research efforts. The development of some effective means to prevent or reduce the occurrence of preterm delivery with its associated high risk for perinatal mortality will depend upon the successful conduct and completion of these intervention studies.

Correlations of birth weight and gestational age across generations

Maternal birth weight is known to be a predictor of offspring birth weight. Less is known about the recurrence of gestational age. In order to estimate the recurrence risk of low birth weight and preterm birth across generations in a population-based sample, 11,092 pairs of mother-firstborn offspring were obtained through an internal linkage in the Norwegian Birth Registry based on the years 1967-1969 (mothers) and 1986-1989 (offspring). A low correlation coefficient of 0.086 was found for gestational age across generations, whereas the correlation between maternal and offspring birth weight was 0.242. Mothers with birth weight below 2500 g had a significantly increased risk (odds ratio = 3.03, 95% conf. interval 1.79-5.11) of having a low birth weight child compared with mothers with birth weight above 4 kg. On the other hand, if the mother was born before the 37th completed week of gestation, the risk of having a preterm child was not significantly increased (odds ratio = 1.46, conf. interval 0.96-2.21) compared with mothers who were born at term. Thus, in contrast to birth weight, human variation in gestational age does not appear to be influenced by genetic factors to any large degree.

Heterogeneity of perinatal outcomes in the preterm delivery syndrome.

OBJECTIVE: Our aim was to document the differential neonatal morbidity and intrapartum and neonatal mortality of subgroups of preterm delivery. METHODS: This analysis included 38,319 singleton pregnancies, of which 3,304 (8.6%) were preterm deliveries (less than 37 completed weeks) enrolled in the World Health Organization randomized trial of a new antenatal care model. We classified them as preterm deliveries after spontaneous initiation of labor, either with or without maternal obstetric and medical complications; preterm deliveries after prelabor spontaneous rupture of amniotic membranes (PROM), either with or without obstetric and medical complications; and medically indicated preterm deliveries with maternal obstetric and medical complications. Severe neonatal morbidity and neonatal mortality were the primary outcomes. RESULTS: Fifty-six percent of all preterm deliveries were spontaneous, without maternal complications. Small for gestational age was increased only among the medically indicated preterm delivery group (22.3%). Very early preterm delivery (less than 32 weeks of gestation) was highest among PROM with complications (37%). For intrapartum fetal death and neonatal death, after adjusting by gestational age and other confounding variables, we found that the obstetric and medical complications preceding preterm delivery predicted the different risk levels. Conversely, for severe neonatal morbidity the clinical presentation, ie, PROM or medically indicated, predicted the increased risk. CONCLUSION: There are differential neonatal outcomes among preterm deliveries according to clinical presentation, pregnancy complications, gestational age at delivery, and its association with small for gestational age. This syndromic nature of the condition should be considered if preterm delivery is to be fully understood and thus reduced. LEVEL OF EVIDENCE: III