Risk factors for small-for-gestational-age babies: The Auckland Birthweight Collaborative Study

OBJECTIVE: This case-control study determined whether internationally recognized risk factors for small-for-gestational-age (SGA) term babies were applicable in New Zealand. METHODOLOGY: All babies were born at 37 or more completed weeks of gestation in one of three hospitals in Auckland. Cases weighed less than the sex specific 10th percentile for gestational age at birth, and controls (appropriate-for-gestational-age (AGA)) were a random selection of heavier babies. Information was collected by maternal interview and from obstetric databases. RESULTS: Information from 1714 completed interviews (844 SGA and 870 AGA) was available for analysis. Computerized obstetric records were available for 1691 of the 1701 women who consented to such access. In a multivariate analysis allowing for sex, gestational age at birth, social class and other potential confounders, mothers who smoked had a significantly increased risk of an SGA baby (adjusted OR 2.41; 95% CI 1.78-3.28), as did primiparous mothers (adjusted OR 1.34; 95% CI 1.03-1.73), mothers of Indian ethnicity (adjusted OR 3.22; 95% CI 1.95-5.30), women with pre-eclamptic toxaemia (adjusted OR 2.42; 95% CI 1.08-5.40) and those with pre-existing hypertension toxaemia (adjusted OR 5.49; 95% CI 1.81-16.71). Mothers of SGA infants were shorter (P < 0.001) and reported lower prepregnancy body weights (P < 0.001) than mothers of AGA infants. The population attributable fraction for smoking suggests that up to 18% of SGA infants born in the ABC Study could be related to maternal smoking. CONCLUSIONS: Risk factors associated with SGA births in other countries are also important in New Zealand. Smoking in pregnancy is an important and potentially modifiable behaviour, and efforts to decrease the number of women who smoke during pregnancy should be encouraged.     

Evaluating the Role of Birth Weight and Gestational Age on Acute Lymphoblastic Leukemia Risk Among Those of Hispanic Ethnicity

High birth weight is an established risk factor for childhood acute lymphoblastic leukemia (ALL), especially in children younger than 5 years of age at diagnosis. The goal of this study was to explore the association between being born large for gestational age and the risk for ALL by race/ethnicity to determine if the role of this risk factor differed by these characteristics. The authors compared birth certificate data of 575 children diagnosed with ALL who were younger than 5 years and included in the Texas Cancer Registry, Texas Department of Health, between the years 1995 and 2003 with 11,379 controls matched by birth year. Stratified odds ratios were calculated for risk of ALL by birth weight for gestational age, categorized in 3 groups, small, appropriate, and large for gestational age (SGA, AGA, and LGA, respectively), for each race/ethnicity group. The risk of developing ALL was higher among Hispanics who were LGA (odds ratio [OR] = 1.90, 95% confidence interval [CI]: 1.34–2.68) compared with LGA non-Hispanic whites (OR = 1.27, 95% CI: 0.87–1.86) after adjusting for infant gender, year of birth, maternal age, birth order, and presence of Down syndrome. However, the difference was not statistically significant. These results suggest that there may be differences in the association between higher growth in utero and risk of childhood ALL among Hispanics versus non-Hispanic whites.     

Low birthweight in Hausa infants

As infants with low birth weights (LBWs) constitute a group in need of specialized care, the problems of LBW among the Hausas of Nigeria were evaluated. The case records of all liveborn infants of Hausa parents, born at the Maternity Hospital in Katsina, Nigeria between January 1, 1974 and December 31, 1977, were selected for study. The LBW infants i.e., those weighing 2500 g or below were separated, their characteristics studied, and possible etiological factors identified. A comparison of this group was then made with those neonates who weighed more than 2500 g. The duration of gestation was determined from the menstrual history and by appropriate clinical examination before delivery. As data were not considered to be very reliable, no attempt was made to correlate the birth weights with duration of pregnancy. Infants born before the 37th week of pregnancy were labeled as premature. During the study period, 3890 live Hausa infants (2111 males and 1779 females) were born to 3780 mothers. Of these 3890 infants, 408 males and 420 females weighed 2500 g or less. These 828 infants were born to 774 mothers and included 91 sets of twins and 5 sets of triplets though the outcome of all multiple pregnancies were not live births. The maternal age ranged from 13-45 years. The parity ranged from 0-14 but there were more primigravida compared to other parities. All mothers belonged to lower and middle socioeconomic classes. 70% were urban and 30% were rural. The incidence of LBW was 213/1000 live births or 21.3%. 71.1% of these babies weighed between 2000 g and 2500 g; only 1.6% weighed less than 1000 g. The percentage of females among LBW infants was higher (50.7%) as compared to that of males (49.3%). The incidence of LBW was 19.3% among males and 23.6% among females. The monthly and seasonal incidence of LBW was uniform and no seasonal variation could be found. The incidence of LBW was 18.4% among urban women and 23.4% among rural women. The difference was highly significant. The highest percentage of deaths in the present study occurred among infants weighing less than 1000 g and the immediate neonatal death rate declined in each successive higher weight group, exhibiting a strong relationship between LBW and immediate neonatal mortality. Only 1 child died out of 589 who weighed between 2001-2500 g.     

Second-generation consequences of small-for-dates birth

This is the first reported study of birth outcomes of a group of women whose own birth weights and gestational ages had been previously recorded. Births occurring from 1972 to 1983 among 1154 Swedish women, born from 1955 to 1965, were studied. Women who were themselves small for gestational age (SGA) at birth were at increased risk of giving birth to a SGA infant (odds ratio = 2.21, 95% confidence interval = 1.41, 3.48). Women who had been SGA had an even greater increase in risk of giving birth to a preterm infant (odds ratio = 2.96, 95% confidence interval = 1.47, 5.94). Women who were preterm at birth were not at increased risk of giving birth to either preterm (odds ratio = 0.65, 95% confidence interval = 0.15, 2.74) or SGA (odds ratio 1.21, 95% confidence interval = 0.62, 2.38) infants. It is concluded that the long-term effects of intrauterine growth retardation may extend to the next generation; women who had been SGA should be considered at increased risk to give birth to both growth-retarded and preterm infants.     

Relationship between infant birth weight </=2000 g and maternal zinc levels at Muhimbili National Hospital, Dar Es Salaam, Tanzania

The objective of this study was to determine the relationship between infant birth weight or=3000 g and their mothers formed the control group. There were 81 cases and 84 control infant-mother pairs. Maternal and infants venous blood samples were taken after delivery. Plasma zinc was analyzed using Atomic Absorption Spectrophotometer method. Data were analyzed using Epi-info version 6. Logistic regression was used to assess the contribution of other risk factor on infant birth weight. Date was converted to STATA format and logistic regression analysis was done using STATA program version 8. The results showed that there is significant relationship between infant birth weight and maternal zinc levels. Mothers with low zinc levels were two and half time more at risk of having an infant weighing 相似文献   

Fetal macrosomia--a continuing obstetric challenge

BACKGROUND: Macrosomic fetuses represent a continuing challenge in obstetrics. OBJECTIVES: We studied maternal risk factors of fetal macrosomia and maternal and infant outcome in such cases. METHODS: A retrospective cohort study was carried out with a total of 26,961 singleton pregnancies between 1989 and 2001. Records of 886 mothers who gave birth to live born infants weighing > or =4,500 g were compared to those of 26,075 mothers with normal weight (<4,500 g) infants. Multiple regression analysis was used to identify independent reproductive risk factors. Perinatal complications were also assessed. RESULTS: The incidence of fetal macrosomia was 3.4%. Diabetes, previous macrosomic birth, postdatism (>42 weeks of gestation), obesity (BMI > 25 before pregnancy), male infant, gestational diabetes mellitus, and non-smoking were independent risk factors of fetal macrosomia, with adjusted risks of 4.6, 3.1, 3.1, 2.0, 1.9, 1.6, 1.4, respectively. In the macrosomic group, birth and maternal traumas occurred significantly more often than in the control group. However, records of subsequent pregnancies (n = 250) after the study period showed that a previous uncomplicated birth appeared to decrease complication risks. CONCLUSIONS: Most cases of fetal macrosomia occur in low-risk pregnancies and evaluation of maternal risks cannot accurately predict which women will eventually give birth to an overweight newborn. After an uncomplicated birth of a macrosomic infant, vaginal delivery may be a safe option for the infant and mother.     

Mother-infant feeding interaction in full-term small-for-gestational-age infants

Maternal and infant behavior during feeding was assessed in 30 mother-infant dyads: 15 small-for-gestational-age (SGA) infants (birth weights below the 10th percentile) and 15 appropriate-for-gestational-age (AGA) infants (birth weights between the 25th and 90th percentiles). The groups were balanced for gestational age, sex, neonatal risk factors, and maternal age, parity, socioeconomic status, and race. Behaviors indicative of infant feeding difficulties were coded for mother and infant. The SGA mothers had higher frequencies of these behaviors than did their AGA counterparts. Qualitative ratings of interactive behavior were recorded for mother and infant: SGA infants had ratings indicative of less optimal interactions than those of the AGA group. Infant caloric intake (calories per kilogram per feeding) was calculated by first dividing the change in infant weight in grams before feeding and immediately after feeding by the infant's weight before feeding and then converting it to calories. Although no difference in caloric intake was observed between the two groups, infant behaviors and ratings were associated with caloric intake. These data suggest the importance of including neonatal behavior during feeding in the risk assessment of potential growth failure in SGA infants.     

A profile of mothers giving birth to infants with congenital rubella syndrome. An assessment of risk factors

To formulate strategies for elimination of congenital rubella syndrome, it is important to identify risk factors for delivering an infant affected by it. We analyzed cases of congenital rubella syndrome in infants born from 1970 to 1985 and reported to either one of two independent Centers for Disease Control surveillance systems. Mothers of infants with congenital rubella syndrome identified in both surveillance systems were disproportionately younger than mothers giving birth in the United States. The risk for delivering an infant with congenital rubella syndrome was approximately 2.5 times higher for blacks compared with whites for both reporting systems. A total of 18% of infants with congenital rubella syndrome born since 1979 were Hispanic (national population average, 7%). Both surveillance systems showed that, although primiparous mothers were at highest risk, 39% of women delivering infants affected by congenital rubella syndrome had had at least one previous live birth, suggesting that postpartum immunization could have prevented these congenital rubella syndrome cases. Young, black, and Hispanic primiparous women represent populations at elevated risk for delivering a congenital rubella syndrome-affected infant and should be specifically targeted for immunization.     

Maternal smoking and fetal growth of full term infants

Results of investigation into the effects of maternal smoking and other selected independent variables on fetal growth indicated that smoking by gravida was assoicated with reductions in birth weights and crown-heel lengths, but not with ponderal indices of newborn infants. Mothers of single infants were interviewed following delivery and before discharge about the amount of smoking during pregnancy. Infants were weighed and measured at birth, and step-wise multiple regression analyses were used to interpret the data for 4 groups of infants: males born to primiparas, males born to multiparas, females born to primiparas, and females born to multiparas. Results indicate that maternal smoking during pregnancy was associated with reductions in birth weights and crown-heel lengths, but not in ponderal indices of these groups of full-term infants. The effects of smoking on fetal growth did not appear to be related to poor maternal nutrition, and mean weight gains during the last 2 trimesters of pregnancy were not significantly different in smoking and nonsmoking mothers. Conflicting opinions exist concerning whether the reduction in crown-heel lengths are transitory or not; thus further study is recommended.     

Triplets and higher-order multiple births. Time trends and infant mortality.

OBJECTIVES--To describe changes in rates of higher-order multiple births (triplets and higher) between 1972 and 1989, to compare infant mortality rates in infants of higher-order multiple births and singletons born from 1983 through 1985, and to compare infant mortality rates among higher-order multiples born from 1983 through 1985 with rates among those born in 1960. RESEARCH DESIGN--Population-based analysis of live births (1972 through 1989) and infant deaths (1960 and 1983 through 1985) in the United States. The rate of higher-order multiple births was calculated per 100,000 live births. DATA SOURCE--Computerized national natality files for 1972 through 1989 and national linked birth/infant death data sets for 1960 and 1983 through 1985 from the National Center for Health Statistics, Centers for Disease Control. POPULATION--Live births to white and black women in the United States. INTERVENTIONS--None. MAIN RESULTS--Between 1972 through 1974 and 1985 through 1989 the rate of higher-order multiple births increased by 113% among infants of white mothers and by 22% among infants of black mothers. In whites the increase was mostly age specific and was not due to the upward shift in the maternal age distribution. The increase was particularly large in white women aged 30 through 34 years (152%) and 35 through 39 years (165%) and in more highly educated mothers. In blacks the modest increase in the rate of higher-order multiple births was mostly due to an upward shift in the maternal age distribution. From 1983 through 1985, mortality of infants of higher-order multiple births was about 15 times that of singletons. This was due almost entirely to the lower birth weight distribution of infants of higher-order multiple births. Their weight-specific mortality compared favorably with that of singletons. At 500 through 999 g, mortality was about the same. In weight categories between 1000 and 1999 g, mortality rates in higher-order multiple births were much lower: weight-specific relative risks ranged from 0.30 to 0.73. Between 1960 and 1983 through 1985 infant mortality in higher-order multiple births declined by about 50%. CONCLUSIONS--It is likely that much of the increase in the incidence of higher-order multiple births is due to the rise in the use of ovulation-inducing drugs for the treatment of infertility. This increase and the decline in mortality risk have created a much greater need for medical and social services for infants of higher-order multiple births and their families.     

Females born large for gestational age have a doubled risk of giving birth to large for gestational age infants

AIM: To analyse if females born large for gestational age (LGA) have an increased risk to give birth to LGA infants and to study anthropometric characteristics in macrosomic infants of females born LGA. METHODS: The investigation was performed as an intergenerational retrospective study of women born between 1973 and 1983, who delivered their first infant between 1989 and 1999. Birth characteristics of 47,783 females, included in the Swedish Birth Register both as newborns and mothers were analysed. LGA was defined as >2 SD in either birth weight or length for gestational age. The infants were divided into three subgroups: born tall only, born heavy only and born both tall and heavy for gestational age. Multiple logistic and linear regression analyses were performed. RESULTS: Females, born LGA with regard to length or weight, had a two-fold (adjusted OR 1.96, 95% Cl 1.54-2.48) increased risk to give birth to an LGA infant. Females, born LGA concerning weight only, had a 2.6 (adjusted OR 2.63, 95%, 1.85-3.75) fold increased risk of having an LGA offspring heavy only and no elevated risk of giving birth to an offspring that was tall only, compared to females born not LGA. In addition, maternal obesity was associated with a 2.5 (adjusted OR 2.56, 95%, 2.20-2.98) fold increased risk of having an LGA newborn, compared to mothers with normal weight. CONCLUSION: Females, born LGA, have an increased risk to give birth to LGA infants, compared to mothers born not LGA. Maternal overweight increases this risk even further.     

Associations between prepregnancy body mass index,gestational weight gain and weight catch-up in small-for-gestational-age children

Inadequate gestational weight gain (GWG) was related with a higher incidence of small-for-gestational-age (SGA) births than appropriate GWG; however, the long-term association of maternal GWG with weight catch-up growth in SGA children remains unknown. The objective of this study is to evaluate the associations between prepregnancy body mass index (pBMI), GWG and weight catch-up patterns in SGA children. Data were from the Collaborative Perinatal Project, an American multicentre prospective cohort study. A total of 56,990 gravidas were recruited at the first prenatal visit, and children were followed up until school age. Maternal pBMI, GWG and physical growth of the offspring at birth, 4 months, 1 year, 4 years and 7 years old were recorded. The latent class analysis was employed to form weight catch-up growth patterns (appropriate, excessive, slow, regression and no catch-up patterns) in SGA children. SGA children who developed the ‘appropriate catch-up growth’ pattern and whose mothers had appropriate pBMI and GWG were chosen as the reference. Associations between GWG for different pBMI and weight catch-up patterns were analysed by multivariate logistic regression models. A total of 1619 infants (9.45%) were born term SGA. After adjusting for relevant confounders, compared with SGA children whose mothers had appropriate pBMI and GWG, SGA children with maternal prepregnancy underweight (for inadequate GWG, GWG below recommendations, adjusted OR: 2.88, 95% CI: 1.13–7.31; for appropriate/excessive GWG, adjusted OR: 3.07, 95% CI: 1.74–5.42) or with prepregnancy normal weight but inadequate GWG (adjusted OR: 2.14, 95% CI: 1.36–3.38) were at a higher risk of having the ‘no catch-up growth’ pattern. We suggest that SGA children with maternal prepregnancy underweight or inadequate GWG tend to have a poor weight catch-up growth at least until school age.     

Maternal nutritional status mediates the association between maternal age and birth outcomes

Young maternal age during pregnancy is linked with adverse birth outcomes. This study examined the role of maternal nutritional status in the association between maternal age and small for gestational age (SGA) delivery and birth length. We used data from a birth cohort study in Ethiopia, involving women who were 15–24 years of age and their newborns. A mediation analysis was fitted in a sample of 1,422 mother infant dyads for whom data on birth length were available, and 777 dyads for whom gestational age and birth weight was measured. We used commands, medeff for the mediation analysis and medsens for sensitivity analysis in STATA 14. Maternal nutritional status, measured by mid‐upper arm circumference, mediated 21% of the association between maternal age and birth length and 14% of the association with SGA delivery. The average direct effect (ADE) of maternal age on birth length was (β = 0.45, 95% CI [0.17, 0.99]) and the average causal mediated effect (ACME) was (β = 0.12, 95% CI [0.02, 0.15]). We also found an ADE (β = 0.31, 95% CI [0.09, 0.47]) and an ACME of (β = 0.05, 95% CI [0.003, 0.205]) of maternal age on SGA delivery. The sensitivity analysis suggests an unmeasured confounder with a positive correlation of 0.15 and 0.20 between the mediator and the outcome could explain the observed ACME for birth length and SGA, respectively. We cannot make strong causal assertions as the findings suggest the mediator partly explained the total effect of maternal age on both outcomes.     

Gestational age, birth weight, and the risk of hyperkinetic disorder.

AIMS: To study the association between gestational age and birth weight and the risk of clinically verified hyperkinetic disorder. METHODS: Nested case-control study of 834 cases and 20 100 controls with incidence density sampling. RESULTS: Compared with children born at term, children born with gestational ages of 34-36 completed weeks had a 70% increased risk of hyperkinetic disorder (rate ratio (RR) 1.7, 95% confidence interval (CI) 1.2 to 2.5). Children with gestational ages below 34 completed weeks had an almost threefold increased risk (RR 2.7, 95% CI 1.8 to 4.1). Children born at term with birth weights of 1500-2499 g had a 90% increased risk of hyperkinetic disorder (RR 1.9, 95% CI 1.2 to 2.9), and children with birth weights of 2500-2999 g had a 50% increased risk (RR 1.5, 95% CI 1.2 to 1.8) compared with children born at term with birth weights above 2999 g. The results were adjusted for socioeconomic status of the parents, family history of psychiatric disorders, conduct disorders, comorbidity, and maternal smoking during pregnancy. Results related to birth weight were unchanged after adjusting for differences in gestational age. CONCLUSIONS: Children born preterm, also close to term, and children born at term with low birth weights (1500-2499 g) have an increased risk of clinically verified hyperkinetic disorder. These findings have important public health perspectives because the majority of preterm babies are born close to term.     

Effect of delayed cord clamping on iron stores in infants born to anemic mothers: a randomized controlled trial

OBJECTIVE:To study the effects of cord clamping on iron stores of infants born to anemic mothers at 3 months of age. DESIGN: Randomized controlled trial. SETTING: Teaching hospital. METHODS: Infants born to mothers with hemoglobin (Hb)<100 g/L were randomized at delivery to either immediate cord clamping (early group) or cord clamping delayed till descent of placenta into vagina (delayed group). The outcome measures were infant's hemoglobin and serum ferritin 3 months after delivery. RESULTS: There were 102 neonates randomized to early (n = 43) or delayed cord clamping (n = 59). The groups were comparable for maternal age, parity, weight and supplemental iron intake, infant s birth weight, gestation and sex. The mean infant ferritin and Hb at 3 months were significantly higher in the delayed clamping group (118.4 microg/L and 99 g/L) than in the early clamping group (73 microg/L and 88 g/L). The mean decrease in Hb (g/L) at 3 months adjusted for co-variates was significantly less in the delayed clamping group compared to the early clamping group (-1.09, 95% CI-1.58 to -0.62, p >0.001). The odds for anemia (<100 g/L) at 3 months was 7.7 (95% CI 1.84-34.9) times higher in the early compared to the delayed clamping group. CONCLUSION: Iron stores and Hb in infancy can be improved in neonates born to anemic mothers by delaying cord clamping at birth.     

Maternal education and the incidence and duration of breast feeding: a prospective study

INTRODUCTION: Duration of breast feeding and factors possibly affecting duration were studied in a population of 2174 newborn infants, with gestational age of >37 weeks, who were born in the Department of Obstetrics and Gynaecology at the University of Florence Hospital between November 15, 1997, and November 14, 1998. PATIENTS AND METHODS: Nine hundred mothers agreed to participate in the study. Five questionnaires were completed at the end of the 1st, 3rd, 6th, 9th, and 12th postpartum month. These dealt with infant feeding practices, including breast feeding during the previous week. Breast feeding duration was defined as short (1 month); medium-short (>1 month-<3 months); medium (>3-<6 months); medium-long (>6-<9 months), and long (>9 months). RESULTS: The authors found that 76.3%, 64.7%, 42.3%, 26.4%, and 17% of mothers were still breast feeding at 1, 3, 6, 9, and 12 months after delivery, respectively. The multivariate analysis of the correspondence shows that lack of breast feeding is associated with a birth weight of less than 3000 g, a low level of maternal education, and maternal profession as a housewife or blue collar worker in the commercial sector. A period of breast feeding defined as short or medium-short is associated with mothers who smoke, primiparous mothers, and absence of maternal allergy. The survival curves highlight how the single factor of smoking is an element that leads to a significant difference in the duration of breast feeding. The multiple Cox regression analysis shows a significant negative influence associated with birth weight of less than 3000 g, maternal smoking, and first parity. Above all, among low-birth-weight infants of mothers who smoke, there is a strong correlation with a shorter duration of breast feeding. DISCUSSION: There is still a need for programs that support and encourage breast feeding, focusing particularly on mothers with a low level of education who give birth to a low-weight infant, primiparous mothers, and smokers.     

Association between low birth weight and infant mortality in children born to human immunodeficiency virus 1-infected mothers in Tanzania

BACKGROUND: The relationship between low birth weight and infant mortality among children born to human immunodeficiency virus (HIV)-infected mothers has not been thoroughly investigated. METHODS: A total of 1078 HIV-infected pregnant women in Tanzania were followed up until delivery and with their infants thereafter. The babies' HIV status was assessed at birth, 6 weeks and every 3 months thereafter. Using Cox proportional hazards models, we estimated the associations of low birth weight with neonatal, post-neonatal and infant mortality and further examined whether the association between low birth weight and mortality was modified by pediatric HIV infection. RESULTS: Among 823 singletons, low birth weight was strongly related to neonatal mortality (relative risk, 5.14; 95% confidence interval, 2.32-11.39). The association with postneonatal mortality was modified by child's HIV status. Among infants who were either negative or indeterminate at 6 weeks of age, low birth weight was associated with a 3-fold increased risk of mortality (relative risk, 3.16; 95% confidence interval, 1.36-7.37). In the positive infants, however, the association was no longer significant. CONCLUSIONS: Although the importance of preventing HIV transmission cannot be overemphasized, efforts to reduce the incidence of low birth weight would enhance the benefit of preventing HIV transmission. Even in populations with no access to antiretroviral treatments, interventions to reduce the incidence of low birth weight would result in a significant reduction in infant mortality.     

Risk factors for preterm and small-for-gestational-age babies: a cohort from the Pacific Islands Families Study

AIM: To explore risk factors that are associated with preterm birth and full-term small-for-gestational-age (SGA) birth for a Pacific population. METHODS: Data were gathered from the Pacific Islands Families Study. Mothers of a cohort of 1398 Pacific infants born in South Auckland, New Zealand during 2000 were interviewed when their infants were 6 weeks old. Mothers were questioned regarding maternal health, antenatal care and life-style behaviours. Data regarding birth outcomes were obtained from hospital records. Analyses focused on 1324 biological mothers who gave birth to a singleton and had valid data for birth outcomes. RESULTS: Of 1324 singleton infants, the mean birthweight was 3.60 kg with standard deviation of 0.60 kg. Fifty-two (3.9%) had birthweight less than 2500 g. Ninety-four (7.1%) were born at less than 37 weeks of gestation. Most socio-demographic factors were not associated with poor birth outcomes. Primiparous birth, less frequent attendance of antenatal care and mother's history of high blood pressure were associated with preterm birth and SGA. Smoking during pregnancy increased the odds of having an SGA but not preterm birth. On the other hand, unplanned/unsure pregnancy and prior early pregnancy loss were associated with preterm birth but not SGA. CONCLUSION: Corroborating research conducted with other populations, most of the internationally and nationally recognised risk factors for preterm birth and SGA are also important for Pacific people. Smoking seems to explain more poor birth outcomes in Pacific Islands than in the New Zealand population as a whole.     

Perinatal outcome in an obstetric cohort of Mozambican women

A prospective cohort of 908 consecutively enrolled pregnant women with biparietal diameter (DBP) compatible with gestational age equal to or below 21 weeks were followed up regularly at 2-4 weeks intervals. Normal antenatal care routine was applied. The newborns were followed until 7 days postpartum. The setting was two suburban antenatal clinics in Maputo and the delivery ward at the Maputo Central Hospital. The main outcome variables were low birth weight (LBW), preterm delivery, intrauterine fetal death, perinatal death and small for gestational age (SGA). For each of these variables the odds ratio for maternal risk factors was estimated with 95 per cent confidence interval and multiple logistic regression analysis was used. LBW occurred in 16.2 per cent and low maternal weight, low weight gain during pregnancy and not having a living child were risk factors. Prevalence of preterm birth was 15.4 per cent and low weight gain during pregnancy and malaria in the perinatal period were risk factors. Four per cent of mothers delivered stillborns and syphilis serology (positive VDRL test) was a risk factor. Perinatal death occurred in 4.7 per cent. These deaths were associated with being SGA, LBW or preterm at birth. Of the cohort women, 9.7 per cent delivered SGA newborns. It was concluded that maternal constitutional factors, particularly maternal weight gain, maternal height and maternal weight as well as syphilis and malaria during pregnancy, need to be given attention concerning the adverse outcomes addressed. The establishment of an obstetric cohort, followed prospectively, was possible in a low-income setting with limited numbers lost to follow-up at delivery.     

Maternal nutritional status, diabetes and risk of macrosomia among Native Canadian women

Multivariate methods were used to identify risk factors for macrosomia (birth weight >4000 g) among 741 singleton births to Native Canadian women from Sioux Lookout Zone, Ontario, Canada, in 1990–1993. The average birth weight was 3691±577 g, and 29.2% of infants weighed more than 4000 g at birth. Macrosomic infants were born at later gestational ages and were more likely to be male. Women delivering macrosomic infants were taller, entered pregnancy with higher body mass indexes (BMI) and gained more weight during pregnancy, but were less likely to smoke cigarettes. They were more likely to have previously delivered a macrosomic infant and to have had gestational diabetes mellitus (GDM). Risk of macrosomia was associated with maternal glycemic status; women with pre-existing diabetes were at greatest risk, followed by those with GDM A₂ (fasting glucose ≥6 mmol/l). Women with GDM A₁ (fasting glucose <6 mmol/l) were not at increased risk for delivering a macrosomic infant, but glucose-tolerant women with high glucose concentrations 1 h after the 50 g challenge were at somewhat increased risk. Maternal glycemic status and maternal nutritional status before and during pregnancy are important determinants of macrosomia in this native population.