Quality of antenatal care and its dose-response relationship with birth weight in a maternal and child health training institute in Bangladesh

Four hundred and sixty-five pregnant women and their newborn babies were studied at a maternal and child health training institute in Dhaka, Bangladesh, between July 2002 and June 2003 with the objective of (1) examining the relationship between birth weight and maternal factors, and, if there was a dose-response relationship between quality of antenatal care and birth weight, (2) predicting the number of antenatal visits required for women with different significant characteristics to reduce the incidence of low-birth-weight babies. The study revealed that 23.2% of the babies were of low birth weight according to the WHO cut-off point of <2500 g. Mean birth weight was 2674.19+/-425.31 g. A low birth weight was more common in younger (<20 years) and older (> or =30 years) mothers, the low-income group and those with little or no education. The mean birth weight of the babies increased with an increase in quality of antenatal care. The babies of the mothers who had 6+ antenatal visits were found to be 727.26 g heavier than those who had 1-3 visits and 325.88 g heavier than those who had 4-5 visits. No significant relationship was found between number of conception, birth-to-conception interval, BMI at first visit, sex of the newborn and birth weight. Further, from multiple regression analysis (stepwise), it was revealed that number of antenatal visits, educational level of the mother and per capita yearly income had independent effects on birth weight after controlling the effect of each variable. Using multiple regression analysis, the estimated number of antenatal visits required to reduce the incidence of low-birth-weight babies for women with no education and below-average per capita income status was 6; the number required for women with no education and above-average per capita income status was 5; and that for women with education and with any category of income status was 4 visits. So there is a need to stratify women according to their income and educational status so that, along with other measures, the required number of antenatal visits can be estimated beforehand to reduce the incidence of low-birth-weight babies.     

Birthweight and sociobiological factors in Ilorin, Nigeria

Social and biological factors influencing birthweight of 3053 Ilorin babies were studied. The mean birth weights were 2.998 kg +/- 0.133 (SD) for males and 2.932 kg +/- 0.154 (SD) for females. Multiple regression analysis showed that maternal weight, height, age, education and ethnicity, and child's sex, significantly affected birthweight of infants. Some quadratic and interaction terms also contributed significantly to the prediction of birthweight. The strategies to control the incidence of low birth weight are discussed.     

Paternal age and the occurrence of birth defects

The association between paternal age and the occurrence of birth defects was studied using data collected in Metropolitan Atlanta. Paternal-age information for babies born with defects was obtained from birth certificates, hospital records, and interviews with mothers; for babies born without defects, the information was obtained from birth certificates. Several statistical techniques were used to evaluate the paternal-age-birth-defects associations for 86 groups of defects. Logistic regression analysis that controlled for maternal age and race indicated that older fathers had a somewhat higher risk for having babies with defects, when all types of defects were combined; an equivalent association for older mothers was not found. Logistic regression analyses also indicated modestly higher risks for older fathers for having babies with ventricular septal defects and atrial septal defects and substantially higher risks for having babies with defects classified in the category chondrodystrophy (largely sporadic achondroplasia) and babies with situs inversus. An association between elevated paternal age and situs inversus has not been reported before; the magnitude of the estimated increased risk for situs inversus was about the same as that found in this study for chondrodystrophy.     

The incidence of Down's syndrome and progress towards its reduction

Down's syndrome is the most common autosomal aberration and single cause of mental retardation in man. There is a close relation between advanced maternal age and Down's syndrome. The limitation of family size has made a considerable impact on the incidence of Down's syndrome. In Denmark in the 1950s, 50% of Down's syndrome cases were born to mothers over the age of 35. The percentage went down to 25% in the 1970s and was reduced by prenatal diagnosis to 8% in the 1980s. For the period 1980-85 we followed the birth prevalence closely for different maternal age groups. The birth prevalence was lowered for the age group over 35, but there was a steady rise for the age groups below 35. Early diagnosis, high rate of survival of light-for-date babies and babies with congenital heart defect, and, possibly, exogenous factors working on gametogenesis might be an explanation. To achieve a reduction in incidence, maternal alpha-fetoprotein (AFP)-serum screening for low values may be a possibility. So far, avoidance, but not primary prevention, of Down's syndrome is available.     

Evaluation of birth defect histories obtained through maternal interviews.

Etiologic studies of birth defects often use family history information provided by parents of patients. The validity of this information has not been adequately assessed. Using data from the Atlanta Birth Defects Case-Control study, we evaluated sensitivity, specificity, and positive predictive value of mothers' responses regarding the presence of birth defects in their offspring. A total of 4929 mothers of infants with major structural defects ascertained by the Metropolitan Atlanta Congenital Defects Program and a total of 3,029 mothers of normal infants were asked whether their babies had had a birth defect or a health problem diagnosed during the first year of life. Interviewers and coders of maternal responses were blinded to the case-control status of infants. Sensitivity (the proportion of case mothers who gave responses that could be coded as denoting a major birth defect) was 61%. Specificity (the proportion of control mothers who gave responses that could not be coded as denoting a major birth defect) was 98%. The positive predictive value (the proportion of mothers who gave a major-birth-defect response who in fact had babies with major birth defects) was estimated as 47%. Sensitivity, specificity, and positive predictive value varied by maternal sociodemographic factors such as race and education, as well as by type of defect. These results suggest that family history data obtained through maternal interviews should be cautiously interpreted and, if not properly validated, may alter estimates of recurrence risks.     

The relationship between maternal characteristics, birth weight and pre-term delivery: evidence from Germany at the end of the 20th century

Using data from a sample of German women, this paper analyzes the relationship between maternal characteristics and infants' birth weight and pre-term delivery. Besides typical epidemiological factors that influence the weight of infants, such as the gestational age and maternal BMI at the beginning of the pregnancy, we find a West--East gradient. Within West Germany, there is a small North-South gradient in birth weight, with larger birth weights in the north. Better educated mothers give birth to heavier babies and have a somewhat decreased risk of pre-term delivery. Income plays a minor role, while occupational status is not associated with the weight of infants at all.     

Maternal factors and infant and child mortality in Bangladesh

Using data from The World Fertility Survey, this study shows that the length of the preceding birth interval was the most important maternal factor influencing infant and child mortality risks in Bangladesh. This was such a crucial factor that its effects remain unaltered whether or not the influences of mother's age at birth and birth order are controlled. Infant and child mortality in Bangladesh can be expected to decline considerably if successive births can be spaced by an interval of at least 1.5 years. Child spacing seems to be the major factor requiring program attention. The effects of mother's education and place of residence on infant and child mortality are independent of the effects of maternal age at birth, birth order, and the preceding birth interval. The higher survival chances of children of educated mothers resulted neither through the age at which childbearing started nor through birth spacing but are likely to be related to their smaller family size and to other non-maternal proximate determinants of early mortality.     

Estimates of Incidence and Prevalence of Mongolism and of Congenital Heart Disease in British Columbia

There is a need for accurate ascertainment of incidence and prevalence rates of congenital anomalies. In British Columbia the Registry for Handicapped Children and Adults used in conjunction with vital records has proved a valuable source of information. Birth notifications alone cannot be relied upon for incidence data. It was found that seven times as many cases of congenital heart disease were registered subsequently as were reported at birth. The estimated minimal incidence rates of mongolism and congenital heart disease per 1000 live births were 1.46 and 4.75, respectively. The well-known association of maternal age with mongolism was confirmed. Twice as many babies with congenital heart disease (without mongolism) were born to mothers over 39 years of age as would be expected on the basis of the maternal age distribution for all live births in the population. Prevalence estimates of these two diseases compared favourably with other published estimates.     

Some essential elements in maternal and cord blood in relation to birth weight and gestational age of the baby

Maternal and cord blood were collected from 54 Indian women at parturition and analyzed for Zn, Cu, and Fe by flame atomic absorption spectrophotometry to determine the relationship between levels of these elements in mother’s and infant’s blood and maternal age, birth weight, and gestational age of the baby. The blood Zn level of mothers in the age group 24–28 yr was significantly higher than those of mothers in the age group of 18–23 yr (p<0.05). Similarly, mothers in the 24 to 28-yr group also had higher blood Fe level than mothers in the group 29–38 yr (p<0.05). The levels of Zn, Cu, and Fe were higher in the maternal blood and lower, but not significantly, in the cord blood of low-birth-weight babies than in those of normal-birth-weight babies. However, differences in the levels of Zn, Cu, and Fe between maternal and cord blood of the two birth-weight groups was statistically significant. There were no significant differences in the levels of the three elements in maternal or cord blood by the gestational age of the baby. A weak but significant correlation was found between the birth weight of the baby and the Fe level in the cord blood (r=0.26; p<0.05). Also, weak significant correlations were observed between gestational age of the baby and Fe (r=0.23; p<0.05) and Cu (r=0.31; p<0.05) levels in the cord blood. Although, there are many confounders of low birth weight and preterm deliveries, a diminished placental transfer of these essential elements could be one of the several etiological factors for low birth weight of newborns.     

Birth weight, maternal age, and education: new observations from Connecticut and Virginia

It has been well established that increased maternal education, income, and social status contribute to increased birth weight, as well as reduced risk for low or very low birth weight offspring. However, there remains controversy about the mechanism(s) for this effect, as well as the interactions between these factors, maternal age, and race. Presented here is the analysis of a large, recent sample of over 20,000 consecutive live births in 12 hospitals, about half in Connecticut and half in Virginia, including a maternal population that is educationally and racially diverse. Although information on potentially relevant details such as prenatal care, smoking, occupation, and neighborhood is lacking the data set, there is sufficient information to explore the previously noted strong effect of maternal education on birth weight, as well as the large racial difference in outcome at every educational level after adjustment for the effects of age, marital status, state of residence, and gender of the offspring. However, this relationship was not monotonic, and there were differences in the effect between the white and black families, with black women showing a linear and consistent benefit from education across the range, while whites show a sharp benefit from completion of primary education, less from subsequent schooling. A surprising result was the apparent negative impact of very advanced education (>16 years), with lowered birth weights and higher risk of low birth weight offspring in the women with post-college training. The data also shed some addition light on the effect of age and birth weight. Whites show established improvement in birth outcome to about age 30, with slight decline thereafter, whereas in blacks there was progressive decline in birth weight with rising age starting in adolescence, as previously demonstrated by Geronimus. An additional unexpected observation was a sizable difference between births in Connecticut (larger, fewer low birth weight) than Virginia, correcting for all other covariates. It is hypothesized that this may reflect differences in services used, prenatal care in particular given similarities in smoking rates and other predictors. Because of the non-representativeness of and the limited information available in the present study, the conclusions should be taken as hypotheses for further research rather than definitive.     

Is there a link between cot death and child abuse?

Forty five babies delivered in Oxford obstetric units who subsequently died unexpectedly in infancy were compared with 134 controls matched for maternal age, social class, parity, and year of birth to see whether five factors identified in an earlier study as predictive of subsequent child abuse would also predict the sudden infant death syndrome. Epidemiological findings had suggested certain similarities between the two events. In contrast with babies who were abused, four of the five factors did not distinguish between babies who died suddenly and unexpectedly and their controls, but there was a slight increase in the proportion of mothers of babies who died suddenly and unexpectedly for whom nursing staff thought that support and advice on feeding the baby were needed. Factors predictive of child abuse did not predict sudden infant death in this study.     

Impact of maternal age on birth outcomes: a population-based study of primiparous Brazilian women in the city of São Paulo

The aim of this study is to analyse the impact of maternal age at first birth on low birth weight, preterm birth and low Apgar scores at one minute and at five minutes among live births delivered to primiparous Brazilian women in the city of S?o Paulo. Analyses were based on 73,820 birth records from the 1998 birth cohort. Logistic regression was used to assess the association between maternal age and each outcome variable, controlling for the following risk factors: delivery mode, plurality, sex, maternal education, number of prior losses, prenatal care, race, parity and community development. Maternal ages below 20 and above 30 years were significantly associated with the risks of low birth weight and preterm birth, but no association was found between maternal ages and Apgar score, with the exception that ages 15-19 reduced the odds of a low one-minute score. Even though this result seems to be inconsistent, low birth weight, preterm birth and low Apgar scores measure different dimensions of newborn well-being, and the association of each measure with maternal age is expected to diverge.     

Smoking in pregnancy: associations with skinfold thickness,maternal weight gain,and fetal size at birth.

Skinfold thickness is an index of subcutaneous fat, and certain maternal conditions during pregnancy affect the skinfold thicknesses of the baby. A study was performed to investigate the effect of smoking on skinfold thickness, maternal weight gain, and fetal size at birth. A total of 452 mothers with normal singleton pregnancies were groups as: non-smokers, light-to-moderate smokers, or heavy smokers. Maternal age, height, parity, and duration of pregnancy were similar in the three groups. Heavy smokers gained significantly less weight than non-smokers, but there was no significant difference in skinfold thickness. Babies born to smokers had lower birth weights and smaller head circumferences and were shorter than those born to non-smokers, but skinfold thicknesses were similar. The presence of a normal layer of subcutaneous fat in babies whose mothers smoked suggests that fetal growth retardation is not caused by nutritional deficiencies.     

Malaria Transmission and Fetal Growth

In view of the known relation between infection of the maternal circulation of the placenta with Plasmodium falciparum and impaired fetal growth a study was made of the effect on birth weights of a malaria eradication campaign in the British Solomon Islands. Mean birth weights rose substantially within months of starting antimalarial operations. The increases between 1969 and 1971 averaged 252 g in babies of primigravidae and 165 g in all babies. The proportion of babies with birth weights of less than 2,500 g fell by 8% overall and by 20% among babies of primigravidae. The adverse effect of malaria transmission on fetal growth was apparently reversible if transmission of infection in the community was interrupted up to as late as the third trimester of pregnancy. The beneficial effects of malaria eradication operations on infant survival, child development, and social attitudes in developing countries are discussed.     

Massive transplacental hemorrhage: clinical manifestations in the newborn.

Thirteen newborn infants had transplacental hemorrhage in excess of 30 ml. Fetal blood in the maternal circulation was demonstrated in all cases by the acid elution technique. Anemia was noted in five babies either at birth or within the first 24 hours of life. One baby was stillborn, the death possibly being related to fetal hemorrhage. The other seven babies were clinically normal in spite of massive transplacental hemorrhage. The hemoglobin values and reticulocyte counts were normal at birth and the first 5 days of life. The data on this group of babies suggest that the clinical manifestations of transplacental hemorrhage are related not only to the size of the hemorrhage but also to the time at which the hemorrhage occurs.     

Congenital malformations in Utah

The rate of malformed children in Utah of 11.7 per 1,000 liver births, derived from 128,857 birth certificates, ws not high compared with other non-Utah studies. Rates of selected malformations also were not high. The rate of malformed children varied by county of residence. San Juan County reported the highest percentage of mothers receiving late or infrequent prenatal care, the lowest mean level of public education, and the highest rate of malformed children in the state. The rate was not significantly associated with the large population of Indians residing in that county since by controlling for residence, the variation by race was eliminated. The overall rate was positively associated with maternal age rimarily due to an increased frequency of Down's syndrome. The impact of the "maternal age effect" on the state malformation rate, however, was not large. By controlling for maternal age, the slight association between increased rate of malformed children and increasing birth order was eliminated. The rate of malformed children was higher for parents having a low level of education, infrequent prenatal care, or who were not married. There was also a strong negative association of birth weight with the rate of malformation. Analysis of rates of selected malformations suggested that the low birth weight was a sequela to intrauterine growth retardation caused by severe congenital malformation. The validity and etiologic implications of these results await further investigation.     

Low Birth Weight at Term and Its Determinants in a Tertiary Hospital of Nepal: A Case-Control Study

Birth weight of a child is an important indicator of its vulnerability for childhood illness and chances of survival. A large number of infant deaths can be averted by appropriate management of low birth weight babies and prevention of factors associated with low birth weight. The prevalence of low birth weight babies in Nepal is estimated to be about 12-32%.Our study aimed at identifying major determinants of low birth weight among term babies in Nepal. A hospital-based retrospective case control study was conducted in maternity ward of Tribhuvan University Teaching Hospital from February to July 2011. A total of 155 LBW babies and 310 controls were included in the study. Mothers admitted to maternity ward during the study period were interviewed, medical records were assessed and anthropometric measurements were done. Risk factors, broadly classified into proximal and distal factors, were assessed for any association with birth of low-birth weight babies. Regression analysis revealed that a history of premature delivery (adjusted odds ratio; aOR5.24, CI 1.05-26.28), hard physical work during pregnancy (aOR1.48, CI 0.97-2.26), younger age of mother (aOR1.98, CI 1.15-3.41), mothers with haemoglobin level less than 11gm/dl (aOR0.51, CI0.24-1.07) and lack of consumption of nutritious food during pregnancy (aOR1.99, CI 1.28-3.10) were significantly associated with the birth of LBW babies. These factors should be addressed with appropriate measures so as to decrease the prevalence of low birth weight among term babies in Nepal.     

Common maternal and fetal genetic variants show expected polygenic effects on risk of small- or large-for-gestational-age (SGA or LGA), except in the smallest 3% of babies

Babies born clinically Small- or Large-for-Gestational-Age (SGA or LGA; sex- and gestational age-adjusted birth weight (BW) <10^th or >90^th percentile, respectively), are at higher risks of complications. SGA and LGA include babies who have experienced environment-related growth-restriction or overgrowth, respectively, and babies who are heritably small or large. However, the relative proportions within each group are unclear. We assessed the extent to which common genetic variants underlying variation in birth weight influence the probability of being SGA or LGA. We calculated independent fetal and maternal genetic scores (GS) for BW in 11,951 babies and 5,182 mothers. These scores capture the direct fetal and indirect maternal (via intrauterine environment) genetic contributions to BW, respectively. We also calculated maternal fasting glucose (FG) and systolic blood pressure (SBP) GS. We tested associations between each GS and probability of SGA or LGA. For the BW GS, we used simulations to assess evidence of deviation from an expected polygenic model.Higher BW GS were strongly associated with lower odds of SGA and higher odds of LGA (OR_fetal = 0.75 (0.71,0.80) and 1.32 (1.26,1.39); OR_maternal = 0.81 (0.75,0.88) and 1.17 (1.09,1.25), respectively per 1 decile higher GS). We found evidence that the smallest 3% of babies had a higher BW GS, on average, than expected from their observed birth weight (assuming an additive polygenic model: P_fetal = 0.014, P_maternal = 0.062). Higher maternal SBP GS was associated with higher odds of SGA P = 0.005.We conclude that common genetic variants contribute to risk of SGA and LGA, but that additional factors become more important for risk of SGA in the smallest 3% of babies.     

Birth weight from pregnancies dated by ultrasonography in a multicultural British population.

OBJECTIVE--To produce standard curves of birth weight according to gestational age validated by ultrasonography in the British population, with particular reference to the effects of ethnic origin. DESIGN--Retrospective analysis of computerised obstetric database. SETTING--Three large maternity units associated with Nottingham University with over 16,000 deliveries a year. PATIENTS--41,718 women with ultrasound dated singleton pregnancies and delivery between 168 and 300 days'' gestation. MAIN OUTCOME MEASURES--Length of gestation, ethnic origin, parity, maternal height and weight at booking, smoking during pregnancy; the effect of these variables on birth weight. RESULTS--Birth weights from ultrasound dated pregnancies have a higher population mean and show less flattening of the birthweight curve at term than those of pregnancies dated from menstrual history. Significant differences were observed in mean birth weights of babies of mothers of European origin (3357 g), of Afro-Caribbean origin (3173 g), and from the Indian subcontinent (3096 g). There were also significant interethnic differences in length of gestation, parity, maternal height, booking weight, and smoking habit which affected birth weight. The ethnic differences in birth weight were even greater when the effect of smoking was excluded. CONCLUSIONS--Birthweight standards require precise dating of pregnancy and should describe the population from which they were derived. In a heterogeneous maternity population the accurate assessment of an individual baby''s weight needs to take the factors which affect birthweight standards into consideration.     

Reaching Mothers and Babies with Early Postnatal Home Visits: The Implementation Realities of Achieving High Coverage in Large-Scale Programs

Background

Nearly half of births in low-income countries occur without a skilled attendant, and even fewer mothers and babies have postnatal contact with providers who can deliver preventive or curative services that save lives. Community-based maternal and newborn care programs with postnatal home visits have been tested in Bangladesh, Malawi, and Nepal. This paper examines coverage and content of home visits in pilot areas and factors associated with receipt of postnatal visits.

Methods

Using data from cross-sectional surveys of women with live births (Bangladesh 398, Malawi: 900, Nepal: 615), generalized linear models were used to assess the strength of association between three factors - receipt of home visits during pregnancy, birth place, birth notification - and receipt of home visits within three days after birth. Meta-analytic techniques were used to generate pooled relative risks for each factor adjusting for other independent variables, maternal age, and education.

Findings

The proportion of mothers and newborns receiving home visits within three days after birth was 57% in Bangladesh, 11% in Malawi, and 50% in Nepal. Mothers and newborns were more likely to receive a postnatal home visit within three days if the mother received at least one home visit during pregnancy (OR2.18, CI1.46–3.25), the birth occurred outside a facility (OR1.48, CI1.28–1.73), and the mother reported a CHW was notified of the birth (OR2.66, CI1.40–5.08). Checking the cord was the most frequently reported action; most mothers reported at least one action for newborns.

Conclusions

Reaching mothers and babies with home visits during pregnancy and within three days after birth is achievable using existing community health systems if workers are available; linked to communities; and receive training, supplies, and supervision. In all settings, programs must evaluate what community delivery systems can handle and how to best utilize them to improve postnatal care access.