Adverse birth outcomes in a malarious area

To determine factors associated with fetal growth, preterm delivery and stillbirth in an area of high malaria transmission in Southern Malawi, a cross-sectional study of pregnant women attending and delivering at two study hospitals was undertaken. A total of 243 (17.3%) babies were preterm and 54 (3.7%) stillborn. Intra-uterine growth retardation (IUGR) occurred in 285 (20.3%), of whom 109 (38.2%) were low birthweight and 26 (9.1%) preterm. Factors associated with IUGR were maternal short stature [adjusted odds ratio (AOR) 1.6, 95% confidence interval (CI) 1.0-2.5]; primigravidae (AOR 1.9, 95% CI 1.4-2.7); placental or peripheral malaria at delivery (AOR 1.4, 95% CI 1.0-1.9) and maternal anaemia at recruitment (Hb<8 g/dl) (AOR 1.9, 95% CI 1.3-2.7). Increasing parasite density in the placenta was associated with both IUGR (P=0.008) and prematurity (P=0.02). Factors associated with disproportionate fetal growth were maternal malnutrition [mid-upper arm circumference (MUAC)<23 cm, AOR 1.9, 95% CI 1.0-3.7] and primigravidae (AOR 1.8, 95% CI 1.0-3.1). Preterm delivery and stillbirth were associated with <5 antenatal care visits (AOR 2.2, 95% CI 1.3-3.7 and AOR 3.1, 95% CI 1.4-7.0 respectively) and stillbirth with a positive Venereal Disease Research Laboratory (VDRL) test (AOR 4.7, 95% CI 1.5-14.8). Interventions to reduce poor pregnancy outcomes must reduce the burden of malaria in pregnancy, improve antenatal care and maternal malnutrition.     

Is International or Asian Criteria-based Body Mass Index Associated with Maternal Anaemia,Low Birthweight,and Preterm Births among Thai Population?—An Observational Study

An observational study was conducted in the four southernmost provinces of Thailand aiming at determining the effect of international or Asian criteria-based body mass index (BMI) in predicting maternal anaemia, low birthweight (LBW), and preterm births among pregnant Thai women and the change in haemoglobin (Hb) level during pregnancy. Maternal anaemia was defined as a haemoglobin (Hb) level of <11 g/dL. Anaemia was detected in 27.4% and 26.9% of 1,192 pregnant women at their first prenatal visit and the third trimester respectively. The proportions of overweight and obese women according to the Asian criteria-based pre-pregnancy BMI were higher than the international criteria-based BMI (22.4% and 10.1% vs 15.5% and 3.4% respectively). No significant difference between pre-pregnancy BMI and pregnancy BMI at the first prenatal visit was demonstrated (mean±standard deviation=21.8±4.0 vs 22.8±4.1). Underweight women had a significantly higher prevalence of maternal anaemia, LBW, and preterm birth compared to women with normal weight. Overweight and obese women at pre-pregnancy by the Asian criteria-based BMI had a lower prevalence of anaemia. The Hb levels did not change significantly over time. In addition to BMI, maternal age, parity, and late prenatal visit were independently associated with maternal anaemia, low birthweight, and preterm birth. Underweight pregnant women classified by international or Asian criteria-based BMI increased the risk of maternal anaemia, low birthweight, and preterm birth.Key words: Anaemia, Body mass index, Observational studies, Pregnancy, Thailand     

An analysis of intra-uterine growth retardation in rural Malawi

OBJECTIVE: (1) To describe the sex-specific, birth weight distribution by gestational age of babies born in a malaria endemic, rural area with high maternal HIV prevalence; (2) to assess the contribution of maternal health, nutritional status and obstetric history on intra-uterine growth retardation (IUGR) and prematurity. METHODS: Information was collected on all women attending antenatal services in two hospitals in Chikwawa District, Malawi, and at delivery if at the hospital facilities. Newborns were weighed and gestational age was assessed through post-natal examination (modified Ballard). Sex-specific growth curves were calculated using the LMS method and compared with international reference curves. RESULTS: A total of 1423 live-born singleton babies were enrolled; 14.9% had a birth weight <2500 g, 17.3% were premature (<37 weeks) and 20.3% had IUGR. A fall-off in Malawian growth percentile values occurred between 34 and 37 weeks gestation. Significantly associated with increased IUGR risk were primiparity relative risk (RR) 1.9; 95% CI 1.4--2.6), short maternal stature (RR 1.6; 95% CI 1.0--2.4), anaemia (Hb<8 g/dl) at first antenatal visit (RR 1.6; 95% CI 1.2--2.2) and malaria at delivery (RR 1.4; 95% CI 1.0--1.9). Prematurity risk was associated with primiparity (RR 1.7; 95% CI 1.3--2.4), number of antenatal visits (RR 2.2; 95% CI 1.6--2.9) and arm circumference <23 cm (RR 1.9; 95% CI 1.4--2.5). HIV infection was not associated with IUGR or prematurity. CONCLUSION: The birth-weight-for-gestational-age, sex-specific growth curves should facilitate improved growth monitoring of newborns in African areas where low birth weight and IUGR are common. The prevention of IUGR requires improved malaria control, possibly until late in pregnancy, and reduction of anaemia.     

Risk factors for preterm and term low birthweight in Ahmedabad, India.

To identify and quantify risk factors for preterm and term low birthweight (LBW) we conducted a hospital-based case-control study, linked with a population survey in Ahmedabad, India. The case-control study of 673 term LBW, 644 preterm LBW cases and 1465 controls showed that low maternal weight, poor obstetric history, lack of antenatal care, clinical anaemia and hypertension were significant independent risk factors for both term and preterm LBW. Short interpregnancy interval was associated with an increased risk of preterm LBW birth while primiparous women had increased risk of term LBW. Muslim women were at a reduced risk of term LBW, but other socioeconomic factors did not remain significant after adjusting for these more proximate factors. Estimates of the prevalence of risk factors from the population survey was used to calculate attributable risk. This analysis suggested that a substantial proportion of term and preterm LBW births may be averted by improving maternal nutritional status, anaemia and antenatal care.     

Weight loss during pregnancy is associated with adverse pregnancy outcomes among HIV-1 infected women

In a prospective study of 1002 pregnant, HIV-1 infected Tanzanian women, we examined the incidence of fetal death, preterm delivery, low birth weight (LBW), and small for gestational age (SGA) births in relation to maternal anthropometry at the first prenatal visit, weight loss, and low weight gain during pregnancy. Anthropometric measurements were obtained monthly during the 2nd and 3rd trimesters. Low maternal height and weight at the first visit were significantly related to lower mean birth weight and increased risk of SGA, but not to preterm delivery. Maternal stature < 150 cm was significantly related to fetal death. Weight loss during pregnancy, defined as a negative slope of the regression of weight measurements on the week of gestation, occurred in 10% of the women. It was related to increased relative risk (RR) of fetal death (RR = 1.83, 95% CI = 0.93, 3.57), preterm delivery (RR = 1.85, 95% CI = 1.40, 2.44), and LBW (RR = 2.85, 95% CI = 1.69, 4.79) after adjusting for multivitamin supplementation, height, primiparity, baseline weight, malaria, CD4 cell count, HIV disease stage, and intestinal parasitoses. The significant association with fetal death was stronger for weight loss during the 2nd trimester, whereas increased risks of preterm delivery and LBW were higher for weight loss during the 3rd. Similar but weaker associations were found with low weight gain during pregnancy (slope < 25th percentile). We conclude that poor anthropometric status at the first prenatal visit and weight loss during pregnancy among HIV-1 infected women are strong risk factors for adverse pregnancy outcomes.     

Socio‐economic disparities in pregnancy outcome: why do the poor fare so poorly?

In this paper, we review the evidence bearing on socio-economic disparities in pregnancy outcome, focusing on aetiological factors mediating the disparities in intrauterine growth restriction (IUGR) and preterm birth. We first summarise what is known about the attributable determinants of IUGR and preterm birth, emphasising their quantitative contributions (aetiological fractions) from a public health perspective. We then review studies relating these determinants to socio-economic status and, combined with the evidence about their aetiological fractions, reach some tentative conclusions about their roles as mediators of the socio-economic disparities. Cigarette smoking during pregnancy appears to be the most important mediating factor for IUGR, with low gestational weight gain and short stature also playing substantial roles. For preterm birth, socio-economic gradients in bacterial vaginosis and cigarette smoking appear to explain some of the socio-economic disparities; psychosocial factors may prove even more important, but their aetiological links with preterm birth require further clarification. Research that identifies and quantifies the causal pathways and mechanisms whereby social disadvantage leads to higher risks of IUGR and preterm birth may eventually help to reduce current disparities and improve pregnancy outcome across the entire socio-economic spectrum.     

Is Maternal Smoking during Early Pregnancy a Risk Factor for All Low Birth Weight Infants?

Background

Low birth weight (LBW) infants do not form a homogeneous group; LBW can be caused by prematurity or poor fetal growth manifesting as small for gestational age (SGA) infants or intrauterine growth retardation. We aimed to clarify the relationship of maternal smoking with both SGA and preterm LBW infants.

Methods

The study population comprised pregnant women who registered at the Koshu City between January 1, 1995, and December 31, 2000, and their children. We performed multivariate analyses using multiple logistic regression models to clarify the relationship of maternal smoking during pregnancy with the SGA outcome and preterm birth in LBW infants.

Results

In this study period, 1,329 pregnant women responded to questionnaires, and infant data were collected from 1,100 mothers (follow-up rate: 82.8%). The number of LBW infants was 81 (7.4%). In this cohort, maternal smoking during early pregnancy was associated with LBW and the SGA outcome. Maternal smoking during early pregnancy was a risk factor for LBW with SGA outcome and for LBW with full-term birth. However, it was not a risk factor for LBW with appropriate weight for gestational age (AGA) and LBW with preterm birth.

Conclusion

These results suggested that LBW with AGA and LBW with preterm birth were associated with other risk factors that were not considered in this study, such as periodontal disease. For the prevention of LBW, not only abstinence from smoking during pregnancy but also other methods such as establishing a clinical setting should be adopted.Key words: Infant, Low Birth Weight; Pregnancy; Risk Factors; Smoking     

中国低出生体重儿危险因素的病例对照研究

目的 探讨我国不同特征低出生体重儿发生的有关危险因素。方法 1998年7－10月,对我国11个省44个县市的999例低出生体重儿进行1：！病例对照研究。结果 我国低体重儿发生的危险因素主要为多胎、孕周不足、孕期异常、孕期营养差、母亲疾病史及母亲程度低等,其OR值分别为106．9、18．79、3．42、1．93、2．61和1．43。各危险因素在沿海、内地及边远地区的分布差异有显著性。农村低体重儿的原因主要为宫内发育迟缓（71．6％）,城市低体得儿的原因还包括多胎和早产。早产及宫内发育不全的低出生体重儿之间的危险因素存在差异。结论 有针对性地开展防治工作是降低我国低体重儿出生率的有效措施。     

Antenatal Care Attendance,a Surrogate for Pregnancy Outcome? The Case of Kumasi,Ghana

Antenatal care (ANC) has been shown to influence infant and maternal outcomes. WHO recommends 4 ANC visits for uncomplicated pregnancies. However, pregnant women in Ghana are required to attend 8–13 antenatal visits. We investigated the association of ANC attendance with adverse pregnancy outcomes (defined as low infant birth weight, stillbirth, preterm delivery or small for gestational age). A quantitative cross-sectional study was conducted on 629 women, age 19–48 years who presented for delivery at two selected public hospitals and 16 traditional birth attendants from July to November 2011. Socio-demographic and antenatal information were collected using a structured questionnaire. ANC attendance, medical and obstetric/gynecological history were abstracted from maternal antenatal records. Data were analyzed using Chi square and logistic regression. Twenty-two percent of the women experienced an adverse outcome. Eleven percent of the women attended <4 ANC visits. In an unadjusted model, these women had an increased likelihood of experiencing an adverse outcome (OR 2.27; 95 % CI 1.30–3.94; p = 0.0038). High parity (>5 children) was also associated with adverse birth outcomes. Women screened for syphilis or use of insecticide-treated bed nets had a 40 and 36 % (p = 0.0447 and p = 0.0293) reduced likelihood of experiencing an adverse pregnancy outcome respectively. After adjusting for confounders, attending <4 antenatal visits was associated with adverse pregnancy outcome compared with ≥4 ANC visits (Adjusted OR 2.55; 95 % CI 1.16–5.63; p = 0.0202). Attending <4 antenatal visits and high parity were associated with adverse pregnancy outcomes for uncomplicated pregnancies.     

Population attributable risk for adverse pregnancy outcomes related to smoking in adolescents and adults

BACKGROUND: Little is known about how population-attributable risks (PAR) for adverse birth outcomes due to smoking differ in adolescent and adult pregnancies. METHODS: An analysis of community and hospital-based cross-sectional studies in Liverpool was undertaken to estimate the PAR values of low birthweight (LBW), preterm birth, and small for gestational age (SGA) births resulting from pregnancy smoking covering the period between 1983 and 2003. Maternal smoking status and pregnancy outcomes were available for a sample of 12631 women. RESULTS: The prevalence of maternal pregnancy smoking was 40% in the community sample and 33% in adults and 40% among adolescent pregnancies in the hospital sample. The PAR values (95% CI) associated with LBW, preterm birth and SGA outcomes due to maternal pregnancy smoking in the community sample were 27% (25-30), 13% (11-15) and 25% (23-27), respectively. The PAR values in adults in the hospital sample were 29% (27-31) for LBW, 16% (14-19) for preterm birth and 28% (26-31) for SGA. The corresponding PAR values in adolescents were 39% (34-43), 12% (7-18) and 31% (23-40). The LBW risk attributed to pregnancy smoking in adolescents was significantly higher than for adults (P=0.05). CONCLUSION: About one-third of LBW, one-quarter of SGA and one-sixth of preterm births could be attributed to maternal smoking during pregnancy. The magnitude of the problem was greater among adolescent pregnancies, among whom a sub-group of mothers with very high risk for adverse birth outcomes due to pregnancy smoking was identified.     

Perinatal survival and health after maternal influenza A(H1N1)pdm09 vaccination: A cohort study of pregnancies stratified by trimester of vaccination

Large cohort studies demonstrated the safety of vaccination with the AS03 adjuvanted pandemic influenza vaccine, but data on first trimester vaccination safety are limited.We conducted a nationwide register-based retrospective cohort study in Finland, included singleton pregnancies present on 01 November 2009 and followed them from 01 November 2009 until delivery. Pregnancies with abortive outcome, pregnancies that started before 01 February 2009 and pregnancies of women, who received the AS03 adjuvanted pandemic influenza vaccine prior to the onset of pregnancy, were excluded. Our main outcome measures were hazard ratios comparing the risk of stillbirth, early neonatal death, moderately preterm birth, very preterm birth, moderately low birth weight, very low birth weight, and being small for gestational age between pregnancies exposed and unexposed to maternal influenza A(H1N1)pdm09 vaccination.The study population comprised 43,604 pregnancies; 34,241 (78.5%) women were vaccinated at some stage during pregnancy. The rates of stillbirth, early neonatal death, moderately preterm birth, and moderately low birth weight were similar between pregnant women exposed and unexposed to influenza A(H1N1)pdm09 vaccination. After adjusting for known risk factors, the relative rates were 0.90 (95% confidence interval 0.55–1.45) for very preterm birth, 0.84 (0.61–1.16) for very low birth weight, and 1.17 (0.98–1.40) for being small for gestational age. Also, in the subanalysis of 7839 women vaccinated during the first trimester, the rates did not indicate that maternal vaccination during the first trimester had any adverse impact on perinatal survival and health.The risk of adverse pregnancy outcomes was not associated with the exposure to the AS03 adjuvanted pandemic influenza vaccine. This study adds reassuring evidence on the safety of AS03 adjuvanted influenza vaccines when given in the first trimester and supports the recommendation of influenza vaccination to all pregnant women through all stages of pregnancy.     

Low birth weight: an outcome of poor socio-obstetric interaction

Factors contributing to low birth weight (LBW) include poverty, ignorance, and inability to use health care services. Early marriage and low family income lead to poor maternal nutrition reserves, which lead to reduced fetal nutrition. Poor maternal nutrition is also the result of ignorance, short birth intervals, multi-parity, and lack of prenatal care. Both heavy manual labor and smoking contribute to placental ischemia, which, along with reduced fetal nutrition, leads to intrauterine growth retardation (IUGR). In developing countries, IUGR accounts for over 66% of all LBW neonates. About 7 million Indian babies annually are LBW. This study examined the incidence of LBW among 178 mothers delivering single births at the maternity hospital associated with the Department of Community Medicine of SKIMS, Srinagar, Kashmir, India, during 1989-90. 26.40% (47) of the 178 births were LBW (2500 g). Among 71 first-borns, marriage age was found to be statistically significantly associated with LBW. 31.82% of mothers younger than 20 years had LBW babies, compared to only 6.12% of mothers older than 20 years. The impact ratio, which measured excess LBW, was 4.20. Birth interval was statistically significantly associated with LBW outcome. 55.81% of women with a birth interval of less than 18 months had LBW babies, compared to 20.31% of mothers with longer birth intervals. The impact ratio was 1.75. Gravidity was also statistically associated with LBW babies. 34.58% of multigravida mothers had LBW babies, compared to 14.08% of primigravidae. The impact ratio was 1.46. Presence of prenatal care was statistically associated; the impact ratio was 1.42. 31.30% of illiterate women had LBW babies, compared to only 17.46% among literate women, which indicated significant associations with LBW. Other significant factors were manual labor, maternal smoking, and monthly family income. Reduction of LBW by 10-30% nationally by the year 2000 will be difficult and best accomplished by a high risk approach supplemented by health and nutrition education.     

妊娠期高血压及子痫前期对妊娠及新生儿结局的影响研究

目的 探讨妊娠期高血压及子痫前期对妊娠及新生儿结局的影响,为育龄妇女孕前、孕期及产后保健提供依据,以减少不良妊娠结局的发生,并为新生儿的健康管理提供预警信息。方法 以前瞻性队列研究为基础的巢式病例对照研究,暴露组84例,其中妊娠期高血压39例、子痫前期45例,按1∶1比例分层随机选择对照组(健康孕妇),使其在分娩年龄、分娩孕周、孕前体质指数、孕次、产次五方面成组匹配,比较两组间妊娠结局及新生儿情况的差别,进一步按妊娠期高血压和子痫前期对暴露组分层与对照组比较。结果 暴露组在分娩方式、早产、宫内缺氧、低出生体重儿、转新生儿科或转院、新生儿出生体重、身长、生后1 min和5 min Apgar评分方面与对照组相比,差异均存在统计学意义(P<0.05),且子痫前期导致的不良妊娠及新生儿结局更严重。结论 妊娠期高血压及子痫前期对孕妇及新生儿造成了不良影响,应当加强育龄妇女的保健,积极预防和治疗妊娠期高血压疾病,实现优生。     

Incidence of and socio-demographic risk factors for stillbirth, preterm birth and low birthweight among Zimbabwean women

Data on birth outcomes are important for planning maternal and child health care services in developing countries. Only a few studies have examined frequency of birth outcomes in Zimbabwe, none of which has jointly examined the spectrum of poor birth outcomes across important demographic subgroups. We assessed delivery patterns and birth outcomes in 17 174 births over a one-year period from October 1997 to September 1998 at Harare Hospital, Zimbabwe. The annual rate of stillbirth was 61 per 1000 live births, rate of preterm birth (<37 weeks) was 168 per 1000, and low birthweight (LBW) (<2500 g) was 199 per 1000. Not attending antenatal care (prenatal care) was associated with increased risks of stillbirth [relative risk (RR) = 2.54, 95% CI 2.21, 2.92], preterm delivery [RR = 2.43, 95% CI 2.26, 2.61] and LBW births [RR = 2.16, 95% CI 2.02, 2.31]. Preterm births and LBW births were more likely to be stillborn [RR = 7.26, 95% CI 6.28, 8.39 and RR = 6.85, 95% CI 5.94, 7.91]. In conclusion, the rate of stillbirth is high and is predominantly associated with preterm births and to a lesser extent LBW. Reducing the frequency of stillbirth will require a better understanding of the determinants of preterm births and strategies for addressing this particular subset of high-risk births.     

Induced abortion: not an independent risk factor for pregnancy outcome, but a challenge for health counseling

PURPOSE: Low birth weight (LBW), preterm births, abnormal placentation, and miscarriages have been associated with prior induced abortions. An incidence-related effect has been suggested. The objective of this study is to assess the effects of prior induced abortions on obstetric risk factors and pregnancy outcome in conditions of free high-standard maternity care used by almost the entire pregnant population in Finland. METHODS: We analyzed a population-based database including 26,976 singleton pregnancies from 1989 to 2001, of which 2364 were among women with one prior induced abortion and 355 women had had at least two prior induced abortions. Data included maternal risk factors, pregnancy characteristics, and obstetric outcome measures and were based on results of a self-administered questionnaire at 20 weeks of pregnancy and clinical records. Odds ratios (ORs) concerning pregnancy outcomes were calculated in multiple logistic regression analysis. RESULTS: Induced abortions were associated with several known pregnancy risk factors; specifically, maternal age older than 35 years, unemployment, unmarried status, low educational level, smoking, alcohol consumption, overweight condition, and chronic illnesses. Preterm birth (OR, 1.19; 95% confidence interval, 1.01-1.41) in women with one prior abortion (7.3% versus 6.2%) and LBW (OR, 1.54; 95% confidence interval, 1.02-2.32) in women with two or more prior abortions (7.0% versus 4.7%) appeared to be more common, but after logistic regression analysis, we found no evidence of adverse pregnancy outcomes. CONCLUSIONS: Induced abortion is not an independent risk factor for adverse obstetric outcome. Marked health behavioral pregnancy risks are associated with prior induced abortions. Health counseling of these women is a challenge, but this objective has not yet been achieved.     

Low Birth Weight Across Generations: The Effect of Economic Environment

To determine whether economic environment across generations underlies the association of maternal low birth weight (<2,500 g, LBW) and infant LBW including its preterm (<37 weeks) and intrauterine growth retardation (IUGR) components. Stratified and multilevel logistic regression analyses were performed on an Illinois transgenerational dataset of White and African-American infants (1989–1991) and their mothers (1956–1976) with appended US census income data. Population Attributable Risk percentages were calculated to estimate the percentage of LBW births attributable to maternal LBW. Among Whites, former LBW mothers (N = 651) had an infant LBW rate of 7.1% versus 3.9% for former non-LBW mothers (N = 11,505); RR = 1.8 (1.4–2.5). In multilevel logistic regression models that controlled for economic environment and individual maternal risk factors, the adjusted OR of infant LBW, preterm birth, and intrauterine growth retardation for maternal LBW (compared to non-LBW) equaled 1.8 (1.3–2.5), 1.3 (1.0–1.8), and 1.8 (1.5–2.3), respectively. Among African-Americans, former LBW mothers (N = 3,087) had an infant LBW rate of 19.5% versus 13.3% for former non-LBW mothers (N = 18,558); RR = 1.5 (1.3–1.6). In multilevel logistic models of African-Americans, the adjusted OR of infant LBW, preterm birth, and IUGR for maternal LBW (compared to non-LBW) were 1.6 (1.4–1.8), 1.3 (1.2–1.5), and 1.6 (1.5–1.8), respectively. In both races, approximately five percent of LBW infants with mothers and maternal grandmother who resided in high-income neighborhoods were attributable to maternal LBW. A similar generational transmission of LBW including its component pathways of preterm birth and intrauterine growth retardation occurs in both races independent of economic environment across generations.     

Determinants of low birth weight among HIV-infected pregnant women in Tanzania.

BACKGROUND: Low birth weight (LBW) increases the risk of infant death, but little is known about its causes among HIV-infected populations in sub-Saharan Africa. OBJECTIVE: We assessed sociodemographic, nutritional, immunologic, parasitic, and infant risk factors for birth weight, LBW, and small-for-gestational-age (SGA) status in a cohort of 822 HIV-positive women enrolled in a clinical trial of vitamin supplementation and pregnancy outcomes in Dar es Salaam, Tanzania. DESIGN: Women were enrolled at prenatal care clinics during their second trimester, at which time blood, stool, urine, and genital specimens were collected, and anthropometric measurements and sociodemographic data were recorded. Birth weight was measured at hospital delivery. RESULTS: The mean (+/-SD) birth weight was 3015 +/- 508 g, 11.1% of newborns weighed <2500 g (LBW), and 11.5% were SGA. In multivariate analyses, maternal weight at enrollment and a low CD8 cell count were inversely associated with LBW. Advanced-stage HIV disease, previous history of preterm birth, Plasmodium falciparum malaria, and any helmintic infection were associated with higher risk of LBW. The intestinal parasites Entamoeba histolytica and Strongyloides stercoralis were predictors of LBW despite their low prevalence in the cohort. In a multivariate-adjusted linear regression model, BMI, midupper arm circumference, a CD4 cell count <200 x 10(6) cells/L (200 cells/mm(3)), primiparity, maternal literacy, and infant HIV infection at birth were significantly associated with birth weight in addition to risk factors included in the LBW model. Determinants of SGA included maternal weight, low serum vitamin E concentration, candidiasis, malaria, and infant HIV infection at birth. CONCLUSION: Prevention of HIV disease progression and vertical transmission, improved nutritional status, and better management of malaria and intestinal parasitic infections are likely to reduce the incidence of LBW in Tanzania.     

The effect of timing and frequency of Plasmodium falciparum infection during pregnancy on the risk of low birth weight and maternal anemia

Plasmodium falciparum infection during pregnancy causes maternal anemia and low birth weight (LBW), but the effect of frequency and timing of infection on the severity of these adverse effects is unknown. We conducted a cohort study recruiting 2462 pregnant women in Malawi. Microscopy was used to diagnose malaria at enrollment, follow-up and delivery. Birth weight and maternal hemoglobin were measured at delivery. The association between timing and frequency of infection and LBW and maternal anemia was analyzed using a binomial regression model. Compared with uninfected women, (i) the risk of LBW increased with the number of malaria episodes [one episode: prevalence ratio (PR) 1.62 (95% CI 1.07-2.46); two episodes: PR 2.41 (95% CI 1.39-4.18)]; (ii) the risk for maternal anemia increased with the number of malaria episodes [one episode: PR 1.15 (95% CI 0.86-1.54); two episodes: PR 1.82 (95% CI 1.28-2.62)]; and (iii) the risk of LBW was higher with infection in the second (PR 1.71; 95% CI 1.06-2.74) than third trimester or at delivery (PR 1.55; 95% CI 0.88-2.75). The timing and frequency of P. falciparum infection during pregnancy affected the risk of LBW but only frequency of infection had an effect on the risk of maternal anemia. Identification of gestational periods when malaria causes most adverse outcomes will facilitate effective targeting of interventions.     

Factors associated with repetition of low birthweight: Missouri longitudinal study

The tendency to repeat low birthweight (LBW < 2500 g) was studied in 182 285 linked first and second birth Missouri livebirths for 1978–90, of which 10 701 had first birth LBW. We examined the likelihood of LBW repetition by first birth birthweight, preterm delivery, and small-for-gestational-age (SGA) status by race, and the odd ratios (ORs) of repeat LBW for risk factors such as smoking, in comparison with ORs of second birth LBW among women with normal-weight first births. We found a strong tendency to repeat LBW (21%), especially following more extreme LBW first births. Adjusted ORs for repeat LBW were 10.1 for births that were preterm and SGA; 7.9 for preterm non-SGA; and 6.3 for SGA term births. Significant ORs of LBW repetition were found for smoking (1.52 and 1.85 for smoking in second pregnancy only and both pregnancies, respectively), short interpregnancy interval (1.33), and advanced maternal age (1.17), but the ORs were generally lower than those for women with normal-weight first births. Low pre-pregnancy weight was a significant risk factor for LBW repetition.     

Efficacy of malaria prevention during pregnancy in an area of low and unstable transmission: an individually-randomised placebo-controlled trial using intermittent preventive treatment and insecticide-treated nets in the Kabale Highlands, southwestern Uganda

Intermittent preventive treatment of malaria during pregnancy (IPTp) and insecticide-treated nets (ITN) are recommended malaria interventions during pregnancy; however, there is limited information on their efficacy in areas of low malaria transmission in sub-Saharan Africa. An individually-randomised placebo-controlled trial involving 5775 women of all parities examined the effect of IPTp, ITNs alone, or ITNs used in combination with IPTp on maternal anaemia and low birth weight (LBW) in a highland area of southwestern Uganda. The overall prevalence of malaria infection, maternal anaemia and LBW was 15.0%, 14.7% and 6.5%, respectively. Maternal and fetal outcomes were generally remarkably similar across all intervention groups (P > 0.05 for all outcomes examined). A marginal difference in maternal haemoglobin was observed in the dual intervention group (12.57 g/dl) compared with the IPTp and ITN alone groups (12.40 g/dl and 12.44 g/dl, respectively; P = 0.04), but this was too slight to be of clinical importance. In conclusion, none of the preventive strategies was found to be superior to the others, and no substantial additional benefit to providing both IPTp and ITNs during routine antenatal services was observed. With ITNs offering a number of advantages over IPTp, yet showing comparable efficacy, we discuss why ITNs could be an appropriate preventive strategy for malaria control during pregnancy in areas of low and unstable transmission. [ClinicalTrials.gov identifier: NCT00142207]