Proportion with low birth weight infants in an Indian population and its relationship with maternal age and parity.

The overall proportion of low birth weight infants is found to be relatively higher in the Indian population. Data collected from two hospitals in Calcutta, India indicate that although the proportion of infants weighing less than 2,001 g is approximately 10%, the dependence of this proportion on maternal age and parity is similar to the studies conducted elsewhere, suggesting a definite biological significance of the phenomenon. The proportion of low birth weight infants is found to be the greatest for the first and late pregnancies, the minimum being at the third birth rank. Young mothers showed a tendency to have an increasing proportion of low birth weight infants with increasing birth order; whereas for older mothers a general U-shaped dependence of the proportion on parity is suggest from the analysis.     

Association between Maternal Smoking during Pregnancy and Low Birthweight: Effects by Maternal Age

Background

Maternal smoking during pregnancy has been consistently related to low birthweight. However, older mothers, who are already at risk of giving birth to low birthweight infants, might be even more susceptible to the effects of maternal smoking. Therefore, this study aimed to examine the modified association between maternal smoking and low birthweight by maternal age.

Methods

Data were obtained from a questionnaire survey of all mothers of children born between 2004 and 2010 in Okinawa, Japan who underwent medical check-ups at age 3 months. Variables assessed were maternal smoking during pregnancy, maternal age, gestational age, parity, birth year, and complications during pregnancy. Stratified analyses were performed using a logistic regression model.

Results

In total, 92641 participants provided complete information on all variables. Over the 7 years studied, the proportion of mothers smoking during pregnancy decreased from 10.6% to 5.0%, while the prevalence of low birthweight did not change remarkably (around 10%). Maternal smoking was significantly associated with low birthweight in all age groups. The strength of the association increased with maternal age, both in crude and adjusted models.

Conclusions

Consistent with previous studies conducted in Western countries, this study demonstrates that maternal age has a modifying effect on the association between maternal smoking and birthweight. This finding suggests that specific education and health care programs for older smoking mothers are important to improve their foetal growth.     

Patterns of low birth weight in the Bengali newborns

This paper examines the distribution of low birth weight (2500 g or less) by gestation time, sex, maternal age, parity (birth order), socioeconomic conditions, and season of birth among 5117 single live births born to Bengali mothers at the Ramakrishna Mission Seva Pratisthan Hospital in Calcutta, India. Preterm infants have low birth weight significantly more often than their full term counterparts. Female infants have low birth weights significantly more often than male infants. The infants of poor mothers have lower birth weights in higher order births more often than infants of higher orders born to well-off mothers. Teenaged mothers produce low birth weight babies significantly more often than older mothers. Although the relationship is not significant, low birth weight infants occur more often among 1st and late born infants and less often among 2nd born infants. The season of birth is not significantly associated with birth weight. Less than 10% of low birth weight infants are pre-term, while the rest are full term. The great majority of low birth weight infants are small-for-gestational-age; the minority are small due to curtailed gestational age. The proportion of infants weighing less than 2001 g is only 9%; this figure tallies closely with earlier studies of India.     

Proportion of low birth weight infants in Visakhapatnam (India) and its relationship with maternal age, parity and infants survival

The percentage of low birth weight infants (LBWI) weighing less than 2270 g in Visakhapatnam (Andhra Pradesh) is relatively higher (12.8%) than in other parts of India. The frequency of LBWI is high at birth order 1 and 2. Thereafter the curve does not show any consistency although the mean per cent of LBWI is lesser than in birth order 1 and 2. The minimum frequency is at birth order 3. The maternal classes less than or equal to 20-29 years show a gradual decrease in the frequency of LBWI with increasing age. For mothers of greater than or equal to 30-39 years of age a general U-shaped relation is found. The overall distribution of neonatal deaths is bimodal, with a peak at less than 1350 g and at 1810 g.     

Maternal and neonatal factors influencing premature birth and low birth weight in Australia

This study identified the influences of neonatal and maternal factors on premature birth and low birth weight in New South Wales, Australia. Bivariate and multivariate analyses were used to explore the association of selected neonatal and maternal characteristics with premature birth and low birth weight. The findings of this study showed that premature birth and low birth weight rate significantly varied by infant sex, maternal age, marital status, Aboriginality, parity, maternal smoking behaviour during pregnancy and maternal hypertension. First-born infants, and infants born to mothers aged less than 20 years, or who were single, separated/divorced, Aboriginal or who smoked during the pregnancy, were at increased risk of being premature or of low birth weight. This study also found that risk factors for premature births and low birth weight were similar in both singleton and multiple births. Gestational age was confirmed to be the single most important risk factor for low birth weight. The findings of this study suggest that in order to reduce the incidence of low birth weight and premature births, health improvement strategies should focus on anti-smoking campaigns during pregnancy and other healthcare programmes targeted at the socially disadvantaged populations identified in the study.     

Parental age and the risk of childhood acute myeloid leukemia: results from the Childhood Leukemia International Consortium

BackgroundParental age has been associated with several childhood cancers, albeit the evidence is still inconsistent.AimTo examine the associations of parental age at birth with acute myeloid leukemia (AML) among children aged 0–14 years using individual-level data from the Childhood Leukemia International Consortium (CLIC) and non-CLIC studies.Material/methodsWe analyzed data of 3182 incident AML cases and 8377 controls from 17 studies [seven registry-based case-control (RCC) studies and ten questionnaire-based case-control (QCC) studies]. AML risk in association with parental age was calculated using multiple logistic regression, meta-analyses, and pooled-effect estimates. Models were stratified by age at diagnosis (infants <1 year-old vs. children 1–14 years-old) and by study design, using five-year parental age increments and controlling for sex, ethnicity, birthweight, prematurity, multiple gestation, birth order, maternal smoking and education, age at diagnosis (cases aged 1–14 years), and recruitment time period.ResultsAdjusted odds ratios (ORs) and 95% confidence intervals (CIs) derived from RCC, but not from the QCC, studies showed a higher AML risk for infants of mothers ≥40-year-old (OR = 6.87; 95% CI: 2.12–22.25). There were no associations observed between any other maternal or paternal age group and AML risk for children older than one year.ConclusionsAn increased risk of infant AML with advanced maternal age was found using data from RCC, but not from QCC studies; no parental age-AML associations were observed for older children.     

Birthweight, maternal weight trajectories and global DNA methylation of LINE-1 repetitive elements

Low birthweight, premature birth, intrauterine growth retardation, and maternal malnutrition have been related to an increased risk of cardiovascular disease, type 2 diabetes mellitus, obesity, and neuropsychiatric disorders later in life. Conversely, high birthweight has been linked to future risk of cancer. Global DNA methylation estimated by the methylation of repetitive sequences in the genome is an indicator of susceptibility to chronic diseases. We used data and biospecimens from an epigenetic birth cohort to explore the association between trajectories of fetal and maternal weight and LINE-1 methylation in 319 mother-child dyads. Newborns with low or high birthweight had significantly lower LINE-1 methylation levels in their cord blood compared to normal weight infants after adjusting for gestational age, sex of the child, maternal age at delivery, and maternal smoking during pregnancy (p = 0.007 and p = 0.036, respectively), but the magnitude of the difference was small. Infants born prematurely also had lower LINE-1 methylation levels in cord blood compared to term infants, and this difference, though small, was statistically significant (p = 0.004). We did not find important associations between maternal prepregnancy BMI or gestational weight gain and global methylation of the cord blood or fetal placental tissue. In conclusion, we found significant differences in cord blood LINE-1 methylation among newborns with low and high birthweight as well as among prematurely born infants. Future studies may elucidate whether chromosomal instabilities or other functional consequences of these changes contribute to the increased risk of chronic diseases among individuals with these characteristics.     

Birth weight and non-insulin dependent diabetes: thrifty genotype,thrifty phenotype,or surviving small baby genotype?

OBJECTIVE--To determine the prevalence of diabetes in relation to birth weight in Pima Indians. DESIGN--Follow up study of infants born during 1940-72 who had undergone a glucose tolerance test at ages 20-39 years. SETTING--Gila River Indian community, Arizona. SUBJECTS--1179 American Indians. MAIN OUTCOME MEASURE--Prevalence of non-insulin dependent diabetes mellitus (plasma glucose concentration > or = 11.1 mmol/l two hours after ingestion of carbohydrate). RESULTS--The prevalence was greatest in those with the lowest and highest birth weights. The age adjusted prevalences for birth weights < 2500 g, 2500-4499 g, and > or = 4500 g were 30%, 17%, and 32%, respectively. When age, sex, body mass index, maternal diabetes during pregnancy, and birth year were controlled for, subjects with birth weights < 2500 g had a higher rate than those with weights 2500-4499 g (odds ratio 3.81; 95% confidence interval 1.70 to 8.52). The risk for subsequent diabetes among higher birthweight infants (> or = 4500 g) was associated with maternal diabetes during pregnancy. Most diabetes, however, occurred in subjects with intermediate birth weights (2500-4500 g). CONCLUSIONS--The relation of the prevalence of diabetes to birth weight in the Pima Indians is U shaped and is related to parental diabetes. Low birth weight is associated with non-insulin dependent diabetes. Given the high mortality of low birthweight infants selective survival in infancy of those genetically predisposed to insulin resistance and diabetes provides an explanation for the observed relation between low birth weight and diabetes and the high prevalence of diabetes in many populations.     

Maternal trade-off in treating high-risk children

Low birthweight and the infant's health status are expected to strongly influence the child's reproductive value and, thus, the maternal decisions on the amount and timing of investment. A total of 590 Hungarian primiparous mothers giving birth in the late 1980s were recruited for the longitudinal study. Mothers of high-risk infants shortened the duration of breast-feeding and interbirth intervals, compared to those with an infant of higher survival prospects. The most powerful predictor of the length of the lactation period was the infant's weight at birth, whereas birth spacing was significantly influenced by the health status of the older child. Socioeconomic status had a positive effect on maternal care as well, but it did not change the basic pattern of diminishing maternal care as a function of the infants' low reproductive value. The combination of the above factors resulted in a cumulative effect on maternal investment of mothers with handicapped children of various degrees of risk. An attempt has been made to exclude alternative explanations and to discuss the proximate mechanisms of discriminative parental solicitude.     

Epidemiology of spontaneous premature rupture of membranes: factors in pre-term births

The frequency of spontaneous premature rupture of membranes (PROM) was determined in the pregnancies of 1,848 white mothers and their singleton infants, born at the University of Kansas Medical Center between April 1975 and April 1978. The frequency of PROM increased significantly from a low of 34/707 (4.8 percent) among low-risk mothers, to 40/444 (9.0 percent) among mothers smoking one to 60 cigarettes a day, to 21/204 (10.3 percent) among mothers with multiple adverse maternal practices, and to 12/46 (26 percent) among mothers with selected complications of their pregnancies. The proportion of low birth weight (LBW) (less than 2,500 g) pre-term infants born to PROM mothers increased among the risk factor groups in a similar manner, from a low of 2/34 (6 percent) in low-risk pregnancies to 8/40 (20 percent) among mothers smoking one to 60 cigarettes a day, to 7/21 (33 percent) among mothers with multiple adverse practices, and to 7/12 (58 percent) among mothers with selected complications of pregnancy. The increased incidence of low birth weight pre-term infants born to mothers with PROM was associated with evidence of growth retardation among full-term infants in the high-risk groups. This finding was manifested by reductions in mean birth weights of full-term infants born to high-risk mothers but not observed in full-term infants born to low-risk mothers. The attained growth at birth of low birth weight pre-term infants could not be determined, because appropriate birth weight standards for pre-term infants born to mothers with low-risk pregnancies are not available. These results suggest that growth retardation in fetuses increased the probability of the mothers having PROM prior to the onset of labor, and, if PROM did occur, of having a premature delivery. We hypothesize that the tensile strength of the amnion and chorion is diminished by the same conditions that retard fetal growth, and that this reduction in strength of the fetal membranes contributes to premature rupture of membranes and pre-term delivery.     

The role of bacteria in lactational mastitis and some considerations of the use of antibiotic treatment

Background

The proportion of mothers in Japan who breastfeed exclusively has been low since the 1970s. The purpose of this study was to examine the association between the time of first breastfeed after birth and the proportion of mothers fully breastfeeding up to four months postpartum.

Methods

A survey was conducted using a self-administered questionnaire. The participants were 318 mothers who participated in a physical examination of their four month old infants in Nagasaki City, Japan in 2003.

Results

The time of first breastfeeding up to 120 minutes was significantly associated with the proportion of mothers fully breastfeeding during their stay in the clinic/hospital (p = 0.006), at one month (p = 0.004) and at four months after birth (p = 0.003). There was no significant difference in the proportion of full breastfeeding in mothers who first breastfed between the period of less 30 minutes after birth and that of between 31 and 120 minutes after birth. Logistic regression analysis indicated that the proportion of mothers who continued full breastfeeding at four months was significantly higher in those who breastfed their baby within 120 minutes compared with more than 120 minutes (OR 2.5, p = 0.01), but was not significantly different in those who breastfed within 30 minutes compared with more than 30 minutes (OR 1.8, p = 0.06). Early breastfeeding was affected by caesarean section, premature delivery and severe bleeding during delivery.

Conclusion

Commencement of early breastfeeding was associated with the proportion of mothers who fully breastfed their infants up to four months. Early breastfeeding, especially within two hours, is recommended for child and maternal health.     

Variation of morphophysiological and genetic demographic traits in children with congenital cleft lip and palate

Medical records and questionnaire data have been used to analyze morphophysiological (the birth weight and length) and genetic demographic (maternal age and marriage structure) traits in a sample of children with orofacial malformations (OMs, cleft palate and/or cleft lip) living in Krasnodar Territory, Russia. The sample of children with malformations (including premature infants) differs from the control group in lower birth weight and length and a lower proportion of children with morphophysiological values close to the population average ones, as well as a higher family exogamy level estimated on the basis of marriage structure in the parental and preceding generations. The risk of congenital cleft palate and/or cleft lip is considerably increased is the maternal age is older than 35 years or, to a lower degree, if it is younger than 20 years.     

The influence of antenatal and maternal factors on stillbirths and neonatal deaths in New South Wales, Australia

This study identified the influences of maternal socio-demographic and antenatal factors on stillbirths and neonatal deaths in New South Wales, Australia. Bivariate and multivariate analyses were used to explore the association of selected antenatal and maternal characteristics with stillbirths and neonatal deaths. The findings of this study showed that stillbirths and neonatal deaths significantly varied by infant sex, maternal age, Aboriginality, maternal country of birth, socioeconomic status, parity, maternal smoking behaviour during pregnancy, maternal diabetes mellitus, maternal hypertension, antenatal care, plurality of birth, low birth weight, place of birth, delivery type, maternal deaths and small gestational age. First-born infants, twins and infants born to teenage mothers, Aboriginal mothers, those who smoked during the pregnancy and those of lower socioeconomic status were at increased risk of stillbirths and neonatal deaths. The most common causes of stillbirths were conditions originating in the perinatal period: intrauterine hypoxia and asphyxia. Congenital malformations, including deformities and chromosomal abnormalities, and disorders related to slow fetal growth, short gestation and low birth weight were the most common causes of neonatal deaths. The findings indicate that very low birth weight (less than 2,000 g) contributed 75.6% of the population-attributable risks to stillbirths and 59.4% to neonatal deaths. Low gestational age (less than 32 weeks) accounted for 77.7% of stillbirths and 87.9% of neonatal deaths. The findings of this study suggest that in order to reduce stillbirths and neonatal deaths, it is essential to include strategies to predict and prevent prematurity and low birth weight, and that there is a need to focus on anti-smoking campaigns during pregnancy, optimizing antenatal care and other healthcare programmes targeted at the socially disadvantaged populations identified in this study.     

Relationships between pregnancy spacing,sex of infants,maternal age,and birth order,and neonatal and post‐neonatal mortality in Bangladesh

Abstract

The relationships between length of the interpregnancy interval, outcome of the pregnancy preceding the interval, sex of the infants, pregnancy order, maternal age, and maternal history of previous child deaths and neonatal and postneonatal mortality were explored in a rural Bangladeshi population using a multiple regression analysis. Specific interactions between the interpregnancy interval, outcome of the pregnancy preceding the interval, sex of the infants, and history of previous child deaths were examined. An inverse relationship was observed between postneonatal mortality and the length of the interpregnancy interval when the pregnancy preceding the interval was a surviving infant. No such trend was observed for neonatal mortality. Post‐neonatal mortality rates among children whose mothers had experienced two or more previous child deaths were essentially the same as that for infants whose mothers had experienced 0–1 child deaths when the interpregnancy intervals were more than 24 months. Although female infants have a lower neonatal mortality than male infants, the neonatal mortality rate for female infants conceived less than twelve months following a male infant birth was higher than for a male infant conceived less than twelve months following another male infant birth. Post‐neonatal mortality is consistently higher for female compared to male infants in all interval categories.     

Maternal Height and Preterm Birth: A Study on 192,432 Swedish Women

BackgroundThere is increasing evidence that lower maternal stature is associated with shorter gestational length in the offspring. We examined the association between maternal height and the likelihood of delivering preterm babies in a large and homogeneous cohort of Swedish women.MethodsThis study covers antenatal data from the Swedish Medical Birth Register on 192,432 women (aged 26.0 years on average) born at term, from singleton pregnancies, and of Nordic ethnicity. Continuous associations between women''s heights and the likelihood of preterm birth in the offspring were evaluated. Stratified analyses were also carried out, separating women into different height categories.ResultsEvery cm decrease in maternal stature was associated with 0.2 days shortening of gestational age in the offspring (p<0.0001) and increasing odds of having a child born preterm (OR 1.03), very preterm (OR 1.03), or extremely preterm (OR 1.04). Besides, odds of all categories of preterm birth were highest among the shortest women but lowest among the tallest mothers. Specifically, women of short stature (≤155 cm or ≤-2.0 SDS below the population mean) had greater odds of having preterm (OR 1.65) or very preterm (OR 1.47) infants than women of average stature (-0.5 to 0.5 SDS). When compared to women of tall stature (≥179 cm), mothers of short stature had even greater odds of giving birth to preterm (OR 2.07) or very preterm (OR 2.16) infants.ConclusionsAmong Swedish women, decreasing height was associated with a progressive increase in the odds of having an infant born preterm. Maternal short stature is a likely contributing factor to idiopathic preterm births worldwide, possibly due to maternal anatomical constraints.     

Revisiting the Effect of Maternal Smoking during Pregnancy on Offspring Birthweight: A Quasi-Experimental Sibling Analysis in Sweden

Maternal smoking during pregnancy (SDP) seems associated with reduced birthweight in the offspring. This observation, however, is based on conventional epidemiological analyses, and it might be confounded by unobserved maternal characteristics related to both smoking habits and offspring birth weight. Therefore, we apply a quasi-experimental sibling analysis to revisit previous findings. Using the Swedish Medical Birth Register, we identified 677,922 singletons born between 2002 and 2010 from native Swedish mothers. From this population, we isolated 62,941 siblings from 28,768 mothers with discrepant habits of SDP. We applied conventional and mother-specific multilevel linear regression models to investigate the association between maternal SDP and offspring birthweight. Depending on the mother was light or heavy smoker and the timing of exposition during pregnancy (i.e., first or third trimester), the effect of smoking on birthweight reduction was between 6 and 78 g less marked in the sibling analysis than in the conventional analysis. Sibling analysis showed that continuous smoking reduces birthweight by 162 grams for mothers who were light smokers (1 to 9 cigarettes per day) and 226 g on average for those who were heavy smokers throughout the pregnancy in comparison to non-smoker mothers. Quitting smoking during pregnancy partly counteracted the smoking-related birthweight reduction by 1 to 29 g, and a subsequent smoking relapse during pregnancy reduced birthweight by 77 to 83 g. The sibling analysis provides strong evidence that maternal SDP reduces offspring birthweight, though this reduction was not as great as that observed in the conventional analysis. Our findings support public health interventions aimed to prevent SDP and to persuade those who already smoke to quit and not relapse throughout the pregnancy. Besides, further analyses are needed in order to explain the mechanisms through which smoking reduces birthweight and to identify other maternal characteristics that are common causes of both birthweight reduction and maternal smoking.     

Maternal and alloparental care in a troop of free-ranging Japanese monkeys

In four years of observation of a free-ranging Japanese monkeys, reproductive rate, physical development of infants, maternal care and alloparental care were studied. Primiparous mothers, orphanned mothers and old mothers showed different types of maternal care from typical multiparous mothers, and the reproductive success of each of these categories of mother also differed. Among nulliparae, 2-year-old females showed the most interest in infants. Adult females were generally indifferent to other females' infants and came to act aggressively toward them with increasing age and maternal experience.     

Nutritional services during pregnancy and birthweight: a retrospective matched pair analysis.

Since 1963, unselected prenatal patients at the Royal Victoria Hospital, Montreal, have been given nutritional counselling and, if it was judged necessary, dietary supplementation by the Montreal Diet Dispensary. From uniform data collected for all obstetric patients in 1963--74, 1213 recipients of the dispensary services (89.7% of those available and eligible for matching) were paired with controls matched for date of delivery (within 12 months), religious affiliation, parity, trimester of pregnancy during which prenatal care was begun and weight at the time of conception. The proportion of infants of low birthweight (less than 2500 g) was 5.7% for the recipients and 6.8% for the controls; the difference was not significant, but the recipients'' infants were heavier at birth than the controls'' infants, by an average of 40 g (P less than 0.05). The difference in birthweight was greatest for the infants of women in their first pregnancy (average 61 g) and least for the infants of women with three or more past deliveries (average 9 g). Increased birthweight (by an average of 53 g, P less than 0.02) among the recipients'' infants was limited to those born to women weighing less than 140 lb (63 kg) at the time of conception; among the heavier women the controls had infants who were heavier, but not significantly so. Differences between the groups in duration of gestation and maternal weight gain accounted for only a small part of these differences in birthweight. This study provides evidence that the Montreal Diet Dispensary program significantly increased birthweight. Further efforts must now be directed towards judging the long-term benefit of these changes.     

Influence of maternal pregravid weight, height and body mass index on birth weight of male and female newborns

The study included 2300 healthy couples and their healthy newborns delivered vaginally from singleton, normal term (37-42 weeks) pregnancies in Sibenik, Zadar and Split (Croatia). Both fathers and mothers of male newborns were older and had a higher weight than those of female newborns (p < 0.05). Gestational age and birth weight were higher in male than female newborns (p < 0.001). Increasing maternal pregravid weight led to increasing birth weight of both male and female newborns (p < 0.001). Furthermore, increasing maternal height and body mass index resulted in increasing birth weight of male and female newborns (p < 0.001). Thus, the fathers and mothers of male infants were older than those of female infants (p < 0.05), and increasing pre-gravid body weight, body height and body mass index were associated with a higher birth weight in both male and female newborns.