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.     

Risk factors for low birth weight in a rural community in southern Brazil

This paper reports a study assessing risk factors for low birth weight (LBW), preterm and intrauterine growth retardation (IUGR) in a sample of 936 mothers who delivered babies in the Cangu?u Hospital, a rural area of southern Brazil. Traditional risk factors for delivering LBW, preterm and IUGR were examined. The relative importance of the risk factors was studied through risk calculation and logistic regression analysis. Some risk factors for LBW such as low maternal education and number of prenatal consultations were not associated with the risk of delivering babies in any of the three risk groups. Hospitalization during pregnancy and maternal age less than 20 years were confirmed as risk factors for LBW. In the preterm group, low maternal weight and hospitalization during pregnancy showed significant association after control for confounders. The results suggest that there are specific targets for intervention in each of the three groups, and some traditional risk factors must be redefined according to the characteristics of each population.     

Outcome of hospital deliveries of women living at high altitude: a study from Lhasa in Tibet

AIM: To describe rates of neonatal mortality, low birthweight (LBW), preterm birth and small for gestational age (SGA), and relate outcome to ethnicity and perinatal risk factors of liveborn infants of hospital deliveries in Lhasa. The differences in these variables between ethnic Tibetans and non-Tibetans were also studied. METHODS: Data were prospectively collected on the outcome of all liveborn infants born in four hospitals in the urban area of Lhasa, Tibet, in 2005. RESULT: A total of 2540 liveborn infants were recorded. The rates of LBW, preterm birth and SGA were 13.6%, 5.7% and 22.2%, respectively. Neonatal mortality rate was 42/1000 for the infants born alive in the hospitals. Lower GA, vaginal delivery, foetal distress and lack of prenatal care, but not ethnicity, were associated with increased risk of death in multivariate logistic regression. Tibetans had higher BW and lower rates of LBW, SGA, need of oxygen supplementation and maternal hypertension, but higher rates of foetal distress, caesarean section, multiple births and low Apgar scores. CONCLUSION: This study provided a profile of perinatal-neonatal care of hospital newborn infants in Lhasa, Tibet. The rates of neonatal mortality, LBW and SGA were high. The findings suggest ethnic differences in perinatal-neonatal adaptation to high altitude.     

早产儿的围产因素及防治对策探讨

目的：研究早产的围产因素及寻求相应的预防措施。方法：将我院近5年出生的新生儿2 567例,分为早产儿、足月儿两组,对照分析孕母年龄、胎膜早破、多胎妊娠、前置胎盘、妊高征、胎盘早剥、产前检查等围产因素,同时分析早产儿的并发症。结果：早产儿发生率为6.62%,早产儿组与足月儿组对比,除母亲孕龄差异无显著性外,胎膜早破、多胎妊娠、前置胎盘、妊高征、胎盘早剥,产前检查等因素差异均有显著性(P<0.01 或 0.05)。早产儿的并发症主要是新生儿肺炎、硬肿症、高胆红素血症和颅内出血。胎龄越小,体重越低,死亡率越高。结论：减少早产是降低围产儿死亡的关键,减少早产的发生应加强围产期保健,定期产前检查,对产前并发症采取各种防治措施,提高早产儿的成活率。     

Maternal weight and weight gain in Africans. Its relationship to birth weight

A prospective study on 600 gravid women, 492 of whom eventually delivered normal singleton babies following uncomplicated pregnancies is described. Maternal weight measurements per gestational age were recorded from the 10th week till delivery in these randomly selected women attending regular antenatal clinic. The purpose of this paper is: to describe the observed changes in maternal weight throughout normal term pregnancy; to see if any relationship exists between maternal weight and gestational age of women entering pregnancy with different weights; and to explain how the weight changes affected the birth weights of their babies. Mean maternal weight gained in pregnancy was found to be 13.3 +/- 4.56 kg for all deliveries. The mean weight gained for mothers who delivered term (37-41 weeks) low birth weight babies (LBW, weight 0-2500 g) was 9.53 +/- 3.69 kg and the mean for mothers who had large for gestational age babies (LGA, birth weight greater than or equal to 3800 g) was 15.97 +/- 2.67 kg and the mean for mothers who had standard or normal weight babies (NW, birth weight 2501-3799 g) was 13.05 +/- 4.86 kg. The change in maternal weight per unit time was found to be constant for all mothers from the 12th week for normal pregnancy till delivery (r = 0.97, P less than 0.01) except in the obese mothers, most of whom had no consistent gain in weight throughout pregnancy (r = -0.32). The mothers who delivered LBW infants gained less in every trimester when compared with the standard (NW). The mothers of LGA babies gained more in every trimester than did the standard.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of maternal medical diseases on the newborn

Summary The effects of maternal diseases on neonates have been analysed. Maternal anaemia leads to an increased incidence of low bith weight and preterm babies. The morbidity rate was high in these newborns with an increased incidence of hypoglycamia and scleraema. The perinatal loss was quite high. Hypertensive mothers as well as mothers suffering from chronic urinary tract infection or tuberculosis or cardiac disease also gave rise to low birth weight and preterm babies in greater proportion as compared to the normal. There was an increased morbidity and high perinatal loss in these groups. An increased awareness of the effects of maternal disease states on foetal growth and development will improve both the ability to make prenatal diagnosis of diseases and to plant for improved antenatal care and appropriant care of those newborns who are at hight risk, which in turn will definitely improve the outcome of the progeny and reduce perinatal loss. From the Dept. of paediatics S.M.S. Medical College and Hospital, Jaipur.     

Factors associated with low birthweight in rural Bangladesh

This study examines factors associated with low birthweight (LBW) in rural Bangladesh. Enrolled in early first trimester, 350 women were followed for duration of pregnancy and data gathered on maternal factors such as social, demographic, anthropometric, biochemical measures and newborn's birth weight within 48 hours of birth. Almost a quarter of babies (24%) were born with LBW and mean birth weight was 2961 g. Bivariate analysis found associations between LBW and mother's age, parity, weight and hemoglobin level at booking, weight gain and health problems during pregnancy, tobacco consumption, and gestational age. But no such association was seen for birth spacing, mother's height, economic status, educational level, body mass index, mid upper arm circumference and number of ANC visits. Multivariable analysis revealed gestational age, hemoglobin levels at first visit and weight gain during pregnancy as significant predictors of LBW in this rural setting. Although antenatal care provision is absolutely necessary, intervention approaches that go beyond clinical or primary care settings are also warranted for better nutrition of women. Concerted efforts in health and non-health sectors are necessary for improvement in health and social status of women in order to reduce low birthweight in Bangladesh.     

Growth of premature infants fed own mother's milk supplied with two milk formulas

The purpose of the authors in this article was to evaluate the effects of supplementing maternal milk with two different caloric formulas on the growth of premature newborns until they reached 40 weeks of post-conceptional age. Seventy premature infants weighing < 1750g at birth were randomized: 35 adequate for gestational age (AGA) and 35 small for gestational age received maternal milk and either a special preterm formula or a modified formula. Anthropometric measurements and clinical evaluations were used to determine the nutritional status and the postnatal growth of these infants, who were analyzed in six different moments: at maximum weight loss, at return to birth weight, at definite weight gain, when exclusively fed with formula, at 2000g, and when they reached 40 weeks of post-conceptional age. The AGA premature newborns on preterm formula had greater daily weight gain, cephalic circumference increase and growth. The SGA premature newborns on preterm formula had greater daily weight gain and cephalic circumference increase observed from the third week of life onward. The AGA premature newborns on modified formula had less weight gain and smaller increments in the cephalic circumference. The SGA premature on modified formula had the worst anthropometric results. The preterm formula was more efficient than the modified formula in promoting postnatal growth of AGA and SGA premature infants. We believe that, due to their special characteristics, SGA premature should receive individualized nutritional caloric planning     

晚期早产儿中小于胎龄儿的临床特点

目的探讨晚期早产儿中发生小于胎龄儿(SGA)的围产期因素及新生儿期患病特点。方法对2009年10月至2010年9月在我院新生儿重症监护病房住院、胎龄34～36周的晚期早产儿临床资料进行回顾性分析,比较晚期早产儿中SGA和适于胎龄儿(AGA)的围产期因素及新生儿期患病情况。结果 SGA组(179例)住院天数明显长于AGA组(851例)[(16.4±6.2)天比(11.3±4.1)天,P<0.05]。SGA组母亲妊娠期高血压疾病(HDCP)、多胎妊娠、羊水过少和宫内窘迫的比例均高于AGA组(34.1%比17.9%,29.1%比13.7%,21.2%比12.6%,19.6%11.0%,P均<0.01)。SGA组患儿新生儿窒息、喂养不耐受、颅内出血、低血糖和红细胞增多症的发生率亦明显高于AGA组(12.8%比7.9%,7.8%比3.1%,6.1%比2.6%,27.4%比21.4%,3.4%比0.2%,P均<0.05)。结论母亲HDCP和多胎妊娠是造成晚期早产儿SGA的主要原因,SGA患儿相对于AGA患儿具有更高的患病风险,应针对造成SGA的围产期因素以及新生期疾病特点进行相应预防和干预。     

Perinatal risk factors and intraventricular hemorrhage in newborn infants of birth weight less than or equal to 1,500 g

In a retrospective study in 113 preterm newborns (birth weight less than or equal to 1500 g, gestational age less than 35 weeks) intraventricular hemorrhage (IVH I-IV) determined by serial sonographic examinations was correlated to a number of maternal and neonatal risk factors. While there was no significant correlation to bleeding during the gestation, premature rupture of the membranes, mode of delivery, and age of the mother, incidence of IVH was significantly lower in newborns born to mothers with EPH-gestoses (p less than 0.05). A significant high incidence of IVH was found in very premature newborns (p less than 0.025) and in newborns with hyaline membrane disease (p less than 0.005). No single risk factor for a high incidence of IVH was found. IVH in very low birth weight infants probably is caused by summation of several different perinatal risk factors.     

Antenatal multiple micronutrient supplements versus iron-folic acid supplements and birth outcomes: Analysis by gestational age assessment method

Meta-analyses consistently have found that antenatal multiple micronutrient supplementation (MMS) compared with iron and folic acid (IFA) alone reduce adverse birth outcomes. In 2020, the World Health Organization (WHO) placed a conditional recommendation for MMS and requested additional trials using ultrasounds to establish gestational age, because the evidence on low birthweight (LBW), preterm birth and small for gestational age (SGA) was considered inconsistent. We conducted meta-analyses to determine if the effects of MMS on LBW, preterm birth and SGA differed by gestational age assessment method. Using data from the 16 trials in the WHO analyses, we calculated the effect estimates of MMS versus IFA on birth outcomes (generic inverse variance method and random effects model) stratified by method of gestational age assessment: ultrasound, prospective collection of the date of last menstrual period (LMP) and confirmation of pregnancy by urine test and recall of LMP. The effects of MMS versus IFA on birthweight, preterm birth and SGA appeared consistent across subgroups with no evidence of subgroup differences (p > 0.05). When limited to the seven trials that used ultrasound, the beneficial effects of MMS were demonstrated: risk ratios of 0.87 (95% confidence interval [CI] 0.78–0.97) for LBW, 0.90 (95% CI, 0.79–1.03) for preterm birth and 0.9 (95% CI, 0.83–0.99) for SGA. Sensitivity analyses indicated consistency in the results. These results, together with recent analyses demonstrating comparable effects of MMS (vs. IFA) on maternal anaemia outcomes, strengthen the evidence to support a transition from IFA to MMS programmes in low- and middle-income countries.     

Non-medical factors in perinatal health. A study of socioeconomic anc cultural features of women admitted to the maternity hospital in Lens (Pas-de-Calais)]

BACKGROUND: The aim of this study was to determine the influence of medical and non-medical factors on perinatal health in an underpriviledged area, the ex-coal mines of Lens (Pas-de-Calais). POPULATION AND METHODS: This prospective study concerned 1,000 women who delivered in the maternity hospital of Lens between January 5, 1993 and May 13, 1993. The relationships between preterm delivery, low birth weight and maternal socioeconomic and cultural characteristics were analyzed. RESULTS: The women included presented adverse pregnancy outcomes. Preterm delivery, low birth weight and neonatal transfer rates were respectively 6.9%, 7.3% and 12.7% higher than the average regional rates. In contrast with these results, antenatal care could be considered correct or even better. The poor socioeconomic status of the population appeared to be a very significant perinatal risk factor. CONCLUSION: At present, in an unfavourable regional conjuncture, socioeconomic and cultural factors have adverse effects on perinatal morbidity and mortality independent of medical factors like prenatal care. The prevention of poor perinatal outcome should be based on these data. Not the access to the health care system but the manner of dispensing health care should require great consideration.     

Low birthweight in an urban community in Nigeria

Six thousand, one hundred and thirty-five consecutive live births in six major health centres in the city of Ibadan were studied between September 1982 and March 1983 in order to assess the incidence, distribution and causes of low birthweight (LBW) in an urban community in Nigeria. Of the 6135 live births, 504 (8.2%) were of LBW. Two hundred and thirty-six (62%) of the LBW were small-for-gestational-age (SGA), while 146 (38%) were appropriate-for-gestational-age (AGA). Two hundred and five (87%) of the SGA were term while 115 (79%) of the AGA infants were preterm. Multiple pregnancy was an important cause of LBW, occurring in 4.4% of pregnancies. One hundred and forty-six (2.6%) of the 5631 infants who weighed 2500 g or over and 122 (24.2%) of the LBW infants were products of multiple pregnancy (P less than 0.001). The young (less than 20 years), short statured (less than 155 cm) and primigravid mothers were more likely than the others to give birth to LBW infants (P less than 0.001). Of the obstetric and medical factors examined, pre-eclamptic toxaemia (PET) (P less than 0.01), ante-partum haemorrhage (APH) (P less than 0.01) and anaemia (P less than 0.02) significantly increased the risk of LBW. Pre-eclamptic toxaemia, eclampsia, hypertension and renal diseases tended to be associated with SGA while APH and anaemia were found more often with prematurity. Multiple pregnancy contributed equally to the delivery of preterm and growth-retarded infants. Although no obvious cause could be identified in about two-thirds of the cases, pre-conceptional maternal malnutrition and poor diet in pregnancy might play an important role.     

Epidemiology of low birth weight in Ahmedabad

The study to elucidate epidemiological features of LBW (low birth weight) babies shows incidence of LBW to be 20·37%, out of 481 single births studied in 1982. 6·03% were small for gestational age (SGA). Of LBW babies 61·22% were born preterm (<37 weeks) as compared to 31·85% of normal babies. Of preterm babies 3·3% were SGA, while 7·69% of fullterm babies were SGA. SGA babies were found to be significantly related to parity, being most common in primi, and without antenatal care (ANC). Younger (15–25 years), shorter and primipara mothers were more likely to give birth to LBW babies. Of mothers giving birth to normal babies 85·52% had taken ANC, as compared to 67·34% giving birth to LBW babies. SGA was more common in mothers who had not taken ANC. Young, short and primipara mothers, who are prone to give birth to LBW babies should be detected early and brought under qualitative ANC.     

Maternal anthropometry as predictors of low birth weight

The usefulness of maternal anthropometric parameters i.e. maternal weight (MWt), maternal height (MHt), maternal mid-arm circumference (MMAC) and maternal body mass index (MBMI) as predictors of low birth weight (LBW) was studied in 395 singleton pregnancies. The maternal anthropometric parameters were measured in the first trimester of pregnancy and were plotted against the birth weight of the newborns. Significant positive correlations were observed among MWt and birth weight (r=0.38), MHt and birth weight (r=0.25), MMAC and birth weight (r=0.30) and MBMI and birth weight (r=0.30). The most sensitive being MWt (t=7.796), followed by MMAC (t=5.759), MHt (t=4.706) and MBMI (t=5.89). For prediction of LBW, the critical limits of MWt, MHt, MMAC and MBMI were 45 kg, 152 cm, 22.5 cm, 20 kg/m2 respectively. From these observations, the use of colour-coded weighing machines, height rods and tapes may be devised for use by peripheral health workers and traditional birth attendants for detection of mothers at risk of delivering low birth weight babies (Table 5). Mothers who have anthropometric parameters in the 'red zone' are at risk of delivery LBW infants.     

Risk assessment in birth asphyxia

In developing countries the need for a risk approach in neonatology is obvious because of a high birth rate, high neonatal mortality rate, and limited availability of resources. Quantification of risk, with selected antepartum, intrapartum factors, clinical, and post-mortem findings was done by calculating odds ratio, attributable risk, and 95 per cent confidence limits in 1811 babies, 541 of which were asphyxiated. Primigravidity, history of perinatal death, pregnancy induced hypertension, and antepartum haemorrhage carried higher risk. Abnormal fetal heart rate and meconium passage in amniotic fluid correctly predicted high risk of birth asphyxia. Decreasing risk in premature/low birth weight babies without increase in abdominal deliveries suggested that caesarean sections were unnecessary in preterm deliveries. Clinical monitoring of asphyxiated newborns was adequate enough.     

早产儿和小于胎龄儿发生的危险因素的比较分析

目的 比较早产儿和小于胎龄儿发生的危险因素.方法 选择1 270例排除明确孕母疾病和产科危险因素的新生儿,自制调查问卷调查母亲身高、体重、被动吸烟和不良孕产史等因素,将研究对象分类为早产儿和足月儿、小于胎龄儿和适于胎龄儿,采用多因素logistic 回归分析比较早产儿和小于胎龄儿发生的危险因素.结果 孕期增重<9 kg使早产(OR=1.63,95%CI:1.12~2.07)和小于胎龄儿(OR=1.92,95%CI:1.56~2.58)发生的危险性均增高;母亲既往流产史(OR=1.46,95%CI:1.09~1.93)和早产史(OR=2.63,95%CI:1.81~3.92)是早产儿发生的的独立危险因素;孕母身高<1.55 m(OR=2.46,95%CI:1.78~3.48)、孕前BMI<18.5(OR=2.16,95%CI:1.53~3.16)、被动吸烟(OR=2.24,95%CI:1.65~2.98)是小于胎龄儿发生的的独立危险因素.结论 早产儿和小于胎龄儿的危险因素不同,针对两类特征孕妇应采取不同的预防措施,有针对性地减少两类不良妊娠结局的发生.     

Residential environmental tobacco smoke exposure during pregnancy and low birth weight of neonates: Case control study in a public hospital in Lucknow, India

Objective

To determine whether residential environmental tobacco smoke (ETS) exposure during pregnancy is associated with low birth weight (LBW) neonates and establish a dose response relationship.

Design

Case control study.

Setting

Tertiary care hospital.

Methodology

Mothers giving birth to LBW neonate (<2.5 kg) were cases and those whose neonates weighed ≥2.5 kg at birth were controls. Excluded were women smokers and tobacco chewers, high parity (>3), multiple pregnancy and still births. Included were 100 cases and 200 controls, aged 20 to 30 years. Information was collected on ETS exposure and other risk factors of LBW within 24 hours of delivery. Clinical information like maternal haemoglobin levels, birth weight and gestational age of the neonate was extracted from hospital records.

Results

On univariate analysis, preterm pregnancy, low socioeconomic status, previous LBW neonate, no utilization of antenatal care (ANC), severe anemia and ETS exposure were statistically significantly associated with LBW neonate and controlling for these in logistic regression analysis, adjusted Odds ratio for ETS exposure association with LBW neonate was 3.16 (95% CI=1.88–5.28). A dose response relationship was also found which was statistically significant (10–20 cigarettes smoked/day: OR = 4.06, 95% CI=1.78–9.26 and >20 cigarettes smoked/day, OR = 17.62, 95% CI= 3.76–82.43).

Conclusion

Exposure to ETS during pregnancy is associated with LBW of neonates. Hence, there is an urgent need to increase awareness about health hazards of ETS during pregnancy and bring about behavioural changes accordingly as a one of the strategies to reduce LBW deliveries in India.     

Growth velocity and survival of full-term low birth weight infants in an African rural area (Burkina Faso)]

The objective of the study was to compare weight gain and mortality between full-term low birth weight (LBW) and normal birth weight (NBW) children. METHODS: One hundred and fifty-five full-term children born with LBW (<2500 g) and 280 NBW were recruited retrospectively in a rural health district of Burkina. Growth velocity, maternal characteristics and socio-economic status of families were investigated. RESULTS: Difference in weight means between the two groups decreased gradually from 3 months of age and did no more significantly differ from 8 months (P = 0.213). LBW, higher mother's BMI and number of antenatal care visits were associated with higher weight gain at 7 months. Lower weight gain was observed in children whose mothers had no education or high parity. Mortality risk was higher for LBW children (RR = 4.53; P = 0.005). LBW children's weight gain at 3 months was better than that of NBW infants. Nevertheless LBW children had a high mortality risk in the first year of life. CONCLUSION: Our results suggest that it could be interesting to focus early attention on LBW children without spontaneous catch up growth, to improve maternal nutritional status and girl's education.     

Dietary patterns and diet quality during pregnancy and low birthweight: The PRINCESA cohort

Although the isolated effects of several specific nutrients have been examined, little is known about the relationship between overall maternal diet during pregnancy and fetal development and growth. This study evaluates the association between maternal diet and low birthweight (LBW) in 660 pregnant women from the Pregnancy Research on Inflammation, Nutrition,& City Environment: Systematic Analyses (PRINCESA) cohort in Mexico City. Using prior day dietary intake reported at multiple prenatal visits, diet was assessed prospectively using a priori (Maternal Diet Quality Score [MDQS]) and a posteriori (dietary patterns extracted by factor analysis) approaches. The association between maternal diet and LBW was investigated by logistic regression, controlling for confounders. Adherence to recommended guidelines (higher MDQS) was associated with a reduced risk of LBW (OR, 0.22; 95% confidence interval [0.06, 0.75], P < .05, N = 49) compared with the lowest adherence category (reference group), controlling for maternal age, education, height, marital status, pre‐pregnancy body mass index, parity, energy intake, gestational weight gain, and preterm versus term birth; a posteriori dietary patterns were not associated with LBW risk. Higher adherence to MDQS was associated with a lower risk of having an LBW baby in this sample. Our results support the role of advocating a healthy overall diet, versus individual foods or nutrients, in preventing LBW.