Association of Second and Third Trimester Weight Gain in Pregnancy with Maternal and Fetal Outcomes

Objective

To investigate the association between weekly weight gain, during the second and third trimesters, classified according to the 2009 Institute of Medicine (IOM/NRC) recommendations, and maternal and fetal outcomes.

Methods

Gestational weight gain was evaluated in 2,244 pregnant women of the Brazilian Study of Gestational Diabetes (Estudo Brasileiro do Diabetes Gestacional – EBDG). Outcomes were cesarean delivery, preterm birth and small or large for gestational age birth (SGA, LGA). Associations between inadequate weight gain and outcomes were estimated using robust Poisson regression adjusting for pre-pregnancy body mass index, trimester-specific weight gain, age, height, skin color, parity, education, smoking, alcohol consumption, gestational diabetes and hypertensive disorders in pregnancy.

Results

In fully adjusted models, in the second trimester, insufficient weight gain was associated with SGA (relative risk [RR] 1.72, 95% confidence interval [CI] 1.26–2.33), and excessive weight gain with LGA (RR 1.64, 95% CI 1.16–2.31); in third trimester, excessive weight gain with preterm birth (RR 1.70, 95% CI 1.08–2.70) and cesarean delivery (RR 1.21, 95% CI 1.03–1.44). Women with less than recommended gestational weight gain in the 2^nd trimester had a lesser risk of cesarean deliveries (RR 0.82, 95% CI 0.71–0.96) than women with adequate gestational weight gain in this trimester.

Conclusion

Though insufficient weight gain in the 3^rd trimester was not associated with adverse outcomes, other deviations from recommended weight gain during second and third trimester were associated with adverse pregnancy outcomes. These findings support, in part, the 2009 IOM/NRC recommendations for nutritional monitoring during pregnancy.     

Preventing Slips and Falls through Leisure-Time Physical Activity: Findings from a Study of Limited-Service Restaurants

Background/Objective

Physical activity has been shown to be beneficial at improving health in some medical conditions and in preventing injury. Epidemiologic studies suggest that physical activity is one factor associated with a decreased risk for slips and falls in the older (≥65 years) adult population. While the risk of slips and falls is generally lower in younger than in older adults; little is known of the relative contribution of physical activity in preventing slips and falls in younger adults. We examined whether engagement in leisure-time physical activity (LTPA) was protective of slips and falls among a younger/middle-aged (≤50 years old) working population.

Methods

475 workers from 36 limited-service restaurants in six states in the U.S. were recruited to participate in a prospective cohort study of workplace slipping. Information on LTPA was collected at the time of enrollment. Participants reported their slip experience and work hours weekly for up to 12 weeks. We investigated the association between the rate of slipping and the rate of major slipping (i.e., slips that resulted in a fall and/or injury) and LTPA for workers 50 years of age and younger (n = 433, range 18–50 years old) using a multivariable negative binomial generalized estimating equation model.

Results

The rate of major slips among workers who engaged in moderate (Adjusted Rate Ratio (RR)  = 0.65; 95% Confidence Interval (CI)  =  [0.18–2.44]) and vigorous (RR = 0.64; 95%CI  =  [0.18–2.26]) LTPA, while non-significant, were approximately one-third lower than the rate of major slips among less active workers.

Conclusion

While not statistically significant, the results suggest a potential association between engagement in moderate and vigorous LTPA and the rate of major slips in younger adults. Additional studies that examine the role of occupational and non-occupational physical activity on the risk of slips, trips and falls among younger and middle aged adults appear warranted.     

Genetic,Maternal and Placental Factors in the Association between Birth Weight and Physical Fitness: A Longitudinal Twin Study

Background

Adult cardiorespiratory fitness and muscle strength are related to all-cause and cardiovascular mortality. Both are possibly related to birth weight, but it is unclear what the importance is of genetic, maternal and placental factors in these associations.

Design

Peak oxygen uptake and measures of strength, flexibility and balance were obtained yearly during adolescence (10–18 years) in 114 twin pairs in the Leuven Longitudinal Twin Study. Their birth weights had been collected prospectively within the East Flanders Prospective Twin Survey.

Results

We identified linear associations between birth weight and adolescent vertical jump (b = 1.96 cm per kg birth weight, P = 0.02), arm pull (b = 1.85 kg per kg birth weight P = 0.03) and flamingo balance (b = −1.82 attempts to stand one minute per kg birth weight, P = 0.03). Maximum oxygen uptake appeared to have a U-shaped association with birth weight (the smallest and largest children had the lowest uptake, P = 0.01), but this association was no longer significant after adjustment for parental BMI. Using the individual twin’s deviation from his own twin pair’s average birth weight, we found positive associations between birth weight and adolescent vertical jump (b = 3.49, P = 0.0007) and arm pull (b = 3.44, P = 0.02). Δ scores were calculated within the twin pairs as first born twin minus second born twin. Δ birth weight was associated with Δ vertical jump within MZ twin pairs only (b = 2.63, P = 0.009), which indicates importance of placental factors.

Conclusions

We found evidence for an association between adolescent physical performance (strength, balance and possibly peak oxygen uptake) and birth weight. The associations with vertical jump and arm pull were likely based on individual, more specifically placental (in the case of vertical jump) factors. Our results should be viewed as hypothesis-generating and need confirmation, but potentially support preventive strategies to optimize birth weight, for example via placental function, to target later fitness and health.     

Weight at Birth and Subsequent Fecundability: A Prospective Cohort Study

Objective

To examine the association between a woman''s birth weight and her subsequent fecundability.

Method

In this prospective cohort study, we included 2,773 Danish pregnancy planners enrolled in the internet-based cohort study “Snart-Gravid”, conducted during 2007–2012. Participants were 18–40 years old at study entry, attempting to conceive, and were not receiving fertility treatment. Data on weight at birth were obtained from the Danish Medical Birth Registry and categorized as <2,500 grams, 2,500–2,999 grams, 3,000–3,999 grams, and ≥4,000 grams. In additional analyses, birth weight was categorized according to z-scores for each gestational week at birth. Time-to-pregnancy measured in cycles was used to compute fecundability ratios (FR) and 95% confidence intervals (CI), using a proportional probabilities regression model.

Results

Relative to women with a birth weight of 3,000–3,999 grams, FRs adjusted for gestational age, year of birth, and maternal socio-demographic and medical factors were 0.99 (95% CI: 0.73;1.34), 0.99 (95% CI: 0.87;1.12), and 1.08 (95% CI: 0.94;1.24) for birth weight <2,500 grams, 2,500–2,999 grams, and ≥4,000 grams, respectively. Estimates remained unchanged after further adjustment for markers of the participant''s mother''s fecundability. We obtained similar results when we restricted to women who were born at term, and to women who had attempted to conceive for a maximum of 6 cycles before study entry. Results remained similar when we estimated FRs according to z-scores of birth weight.

Conclusion

Our results indicate that birth weight appears not to be an important determinant of fecundability.     

Perinatal Outcomes by Mode of Assisted Conception and Sub-Fertility in an Australian Data Linkage Cohort

Background

Fertility treatment is associated with increased risk of major birth defects, which varies between in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI), and is significantly reduced by embryo freezing. We therefore examined a range of additional perinatal outcomes for these exposures.

Methods

All patients in South Australia receiving assisted conception between Jan 1986–Dec 2002 were linked to the state-wide perinatal collection (all births/stillbirths ≥20 weeks gestation or 400 g birth weight, n = 306 995). We examined stillbirth, mean birth weight, low birth weight (<2500 g, <1500 g), small size for gestational age (<10th percentile, <3rd percentile), large size for gestational age (>90th percentile), preterm birth (32–<37 weeks, <32 weeks gestation), postterm birth (≥41 weeks gestation), Apgar <7 at 5 minutes and neonatal death.

Results

Relative to spontaneous conceptions, singletons from assisted conception were more likely to be stillborn (OR = 1.82, 95% Confidence Interval (CI) 1.34–2.48), while survivors as a group were comprehensively disadvantaged at birth, including lower birth weight (−109 g, CI −129–−89), very low birth weight (OR = 2.74, CI 2.19–3.43), very preterm birth (OR = 2.30, CI 1.82–2.90) and neonatal death (OR = 2.04, CI 1.27–3.26). Outcomes varied by type of assisted conception. Very low and low birth weight, very preterm and preterm birth, and neonatal death were markedly more common in singleton births from IVF and to a lesser degree, in births from ICSI. Using frozen-embryos eliminated all significant adverse outcomes associated with ICSI but not with IVF. However, frozen-embryo cycles were also associated with increased risk of macrosomia for IVF and ICSI singletons (OR = 1.36, CI 1.02–1.82; OR = 1.55, CI 1.05–2.28). Infertility status without treatment was also associated with adverse outcomes.

Conclusions

Births after assisted conception show an extensive range of compromised outcomes that vary by treatment modality, that are substantially reduced after embryo freezing, but which co-occur with an increased risk of macrosomia.     

Birth weight, breast cancer and the potential mediating hormonal environment

Background

Previous studies have shown that woman’s risk of breast cancer in later life is associated with her infants birth weights. The objective of this study was to determine if this association is independent of breast cancer risk factors, mother’s own birth weight and to evaluate association between infants birth weight and hormonal environment during pregnancy. Independent association would have implications for understanding the mechanism, but also for prediction and prevention of breast cancer.

Methods and Findings

Risk of breast cancer in relation to a first infant’s birth weight, mother’s own birth weight and breast cancer risk factors were evaluated in a prospective cohort of 410 women in the Framingham Study. Serum concentrations of estriol (E3), anti-estrogen alpha-fetoprotein (AFP), and pregnancy-associated plasma protein-A (PAPP-A) were measured in 23,824 pregnant women from a separate prospective cohort, the FASTER trial. During follow-up (median, 14 years) 31 women (7.6 %) were diagnosed with breast cancer. Women with large birth weight infants (in the top quintile) had a higher breast cancer risk compared to other women (hazard ratio (HR), 2.5; 95% confidence interval (CI), 1.2–5.2; P = 0.012). The finding was not affected by adjustment for birth weight of the mother and traditional breast cancer risk factors (adjusted HR, 2.5; 95% CI, 1.2–5.6; P = 0.021). An infant’s birth weight had a strong positive relationship with the mother’s serum E3/AFP ratio and PAPP-A concentration during pregnancy. Adjustment for breast cancer risk factors did not have a material effect on these relationships.

Conclusions

Giving birth to an infant with high birth weight was associated with increased breast cancer risk in later life, independently of mother’s own birth weight and breast cancer risk factors and was also associated with a hormonal environment during pregnancy favoring future breast cancer development and progression.     

Birth Weight and Long-Term Overweight Risk: Systematic Review and a Meta-Analysis Including 643,902 Persons from 66 Studies and 26 Countries Globally

Background

Overweight is among the major challenging health risk factors. It has been claimed that birth weight, being a critical indicator of prenatal developmental conditions, is related to long-term overweight risk. In order to check this important assumption of developmental and preventive medicine, we performed a systematic review and comprehensive meta-analysis.

Methods and Findings

Relevant studies published up to January 2011 that investigated the relation between birth weight and later risk of overweight were identified through literature searches using MEDLINE and EMBASE. For meta-analysis, 66 studies from 26 countries and five continents were identified to be eligible, including 643,902 persons aged 1 to 75 years. We constructed random-effects and fixed-effects models, performed subgroup-analyses, influence-analyses, assessed heterogeneity and publication bias, performed meta-regression analysis as well as analysis of confounder adjusted data. Meta-regression revealed a linear positive relationship between birth weight and later overweight risk (p<0.001). Low birth weight (<2,500 g) was found to be followed by a decreased risk of overweight (odds ratio (OR) = 0.67; 95% confidence interval (CI) 0.59–0.76). High birth weight (>4,000 g) was associated with increased risk of overweight (OR = 1.66; 95% CI 1.55–1.77). Results did not change significantly by using normal birth weight (2,500–4,000 g) as reference category (OR = 0.73, 95% CI 0.63–0.84, and OR = 1.60, 95% CI 1.45–1.77, respectively). Subgroup- and influence-analyses revealed no indication for bias/confounding. Adjusted estimates indicate a doubling of long-term overweight risk in high as compared to normal birth weight subjects (OR = 1.96, 95% CI 1.43–2.67).

Conclusions

Findings demonstrate that low birth weight is followed by a decreased long-term risk of overweight, while high birth weight predisposes for later overweight. Preventing in-utero overnutrition, e.g., by avoiding maternal overnutrition, overweight and/or diabetes during pregnancy, might therefore be a promising strategy of genuine overweight prevention, globally.     

Stability of the Associations between Early Life Risk Indicators and Adolescent Overweight over the Evolving Obesity Epidemic

Background

Pre- and perinatal factors and preschool body size may help identify children developing overweight, but these factors might have changed during the development of the obesity epidemic.

Objective

We aimed to assess the associations between early life risk indicators and overweight at the age of 9 and 15 years at different stages of the obesity epidemic.

Methods

We used two population-based Northern Finland Birth Cohorts including 4111 children born in 1966 (NFBC1966) and 5414 children born in 1985–1986 (NFBC1986). In both cohorts, we used the same a priori defined prenatal factors, maternal body mass index (BMI), birth weight, infant weight (age 5 months and 1 year), and preschool BMI (age 2–5 years). We used internal references in early childhood to define percentiles of body size (<50, 50–75, 75–90 and >90) and generalized linear models to study the association with overweight, according to the International Obesity Taskforce (IOTF) definitions, at the ages of 9 and 15 years.

Results

The prevalence of overweight at the age of 15 was 9% for children born in 1966 and 16% for children born in 1986. However, medians of infant weight and preschool BMI changed little between the cohorts, and we found similar associations between maternal BMI, infant weight, preschool BMI, and later overweight in the two cohorts. At 5 years, children above the 90^th percentile had approximately a 12 times higher risk of being overweight at the age of 15 years compared to children below the 50^th percentile in both cohorts.

Conclusions

The associations between early body size and adolescent overweight showed remarkable stability, despite the increase in prevalence of overweight over the 20 years between the cohorts. Using consequently defined internal percentiles may be a valuable tool in clinical practice.     

Migrant Background and Weight Gain in Early Infancy: Results from the German Study Sample of the IDEFICS Study

Objective

To examine variations in infant weight gain between children of parents with and without migrant background and to investigate how these differences are explained by pre- and perinatal factors.

Methods

We used data on birth weight and weight at six months from well-child check-up books that were collected from a population-based German sample of children in the IDEFICS study (n = 1,287). We calculated unadjusted and adjusted means for weight z-scores at birth and six months later. We applied linear regression for change in weight z-score and we calculated odds ratios and 95% confidence intervals (95% CI) for rapid weight gain by logistic regression, adjusted for biological, social and behavioural factors.

Results

Weight z-scores for migrants and Germans differed slightly at birth, but were markedly increased for Turkish and Eastern European infants at age six months. Turkish infants showed the highest change in weight z-score during the first 6 months (ß = 0.35; 95% CI 0.14–0.56) and an increased probability of rapid weight gain compared with German infants. Examination of the joint effect of migrant and socioeconomic status (SES) showed the greatest change in weight z-scores in Turkish infants from middle SES families (ß = 0.77; 95% CI 0.40–1.14) and infants of parents from Eastern European countries with high SES (ß = 0.72; 95% CI 0.13–1.32).

Conclusions

Our results support the hypothesis that migrant background is an independent risk factor for infant weight gain and suggest that the onset of health inequalities in overweight starts in early infancy.     

The Associations between Bridal Pregnancy and Obstetric Outcomes among Live Births in Korea: Population-Based Study

Objective

In East Asia the recently increased number of marriages in response to pregnancy is an important social issue. This study evaluated the association of marriage preceded by pregnancy (bridal pregnancy) with obstetric outcomes among live births in Korea.

Methods

In this population-based study, 1,152,593 first singleton births were evaluated from data registered in the national birth registration database from 2004 to 2008 in Korea. In the study population, the pregnancy outcomes among live births from the bridal pregnancy group (N = 62,590) were compared with the outcomes of the post-marital pregnancy group (N = 564,749), composed of women who gave birth after 10 months but before 24 months of marriage. The variables preterm birth (PTB; <37 weeks gestation) and low birth weight (LBW; <2.5 kg) were used to determine the primary outcome. The adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated after controlling for socio-demographic factors.

Results

The socio-demographic factors among the bridal pregnancy group were associated with a social disadvantage and particular risk factors. In the subgroup analyses of maternal age, differences in adverse pregnancy outcomes from bridal pregnancy were identified between women in the following age group: (i) ≤19, (ii) 20–39, and (iii) ≥40 years. After the multivariate analysis, the aORs for each age group were 1.47 (95% CI: 1.15–1.89), 1.76 (1.70–1.83), and 1.13 (0.77–1.66), respectively, for PTB and 0.92 (0.70–1.21), 1.60 (1.53–1.66), and 1.11 (0.71–1.74), respectively, for LBW. In the adjusted logistic regression models, bridal pregnancy was associated with PTB (1.76, 1.69–1.82) and LBW (1.53, 1.48–1.59).

Conclusion

Pregnancy outcomes among live births from bridal pregnancies are associated with higher risks for PTB and LBW in Korea.     

Asthma during Pregnancy in a Population-Based Study - Pregnancy Complications and Adverse Perinatal Outcomes

Background

Asthma is one of the most common chronic diseases, and prevalence, severity and medication may have an effect on pregnancy. We examined maternal asthma, asthma severity and control in relation to pregnancy complications, labour characteristics and perinatal outcomes.

Methods

We retrieved data on all singleton births from July 1, 2006 to December 31, 2009, and prescribed drugs and physician-diagnosed asthma on the same women from multiple Swedish registers. The associations were estimated with logistic regression.

Results

In total, 266 045 women gave birth to 284 214 singletons during the study period. Maternal asthma was noted in 26 586 (9.4%) pregnancies. There was an association between maternal asthma and increased risks of pregnancy complications including preeclampsia or eclampsia (adjusted OR 1.15; 95% CI 1.06–1.24) and premature contractions (adj OR 1.52; 95% CI 1.29–1.80). There was also a significant association between maternal asthma and emergency caesarean section (adj OR 1.29; 95% CI 1.23–1.34), low birth weight, and small for gestational age (adj OR 1.23; 95% CI 1.13–1.33). The risk of adverse outcomes such as low birth weight increased with increasing asthma severity. For women with uncontrolled compared to those with controlled asthma the results for adverse outcomes were inconsistent displaying both increased and decreased OR for some outcomes.

Conclusion

Maternal asthma is associated with a number of serious pregnancy complications and adverse perinatal outcomes. Some complications are even more likely with increased asthma severity. With greater awareness and proper management, outcomes would most likely improve.     

Parity and the Risk of Diabetes Mellitus among Chinese Women: A Cross-Sectional Evidence from the Tongji-Dongfeng Cohort Study

Objectives

Little is known about the long-term health impact of pregnancy on women. The objective of this study was to examine the association between parity and the risk of diabetes among a population of Chinese women.

Study design

A total of 14,196 women (aged ≥45 years) from the Dongfeng-Tongji Cohort study who had experienced at least one live birth completed baseline questionnaires, medical examinations, and provided baseline blood samples. Participants were categorized into four groups according to parity (one, two, three, or four or more live births). Logistic regression models were used to investigate the association between parity and the risk of diabetes after controlling potential confounders.

Results

The prevalence of diabetes in the study population was 18.0% (2,552/14,196). Fasting plasma glucose levels increased with the increasing number of live births (P<0.001) and parity had a positive graded association with diabetes without adjustment for any covariates (P for trend <0.001). After adjusting for potential confounders, women who had had two, three, and four or more live births had 1.35 times (95% CI, 1.20–1.52), 1.59 times (95% CI, 1.39–1.82) and 1.44 times (95% CI, 1.21–1.71), respectively, higher risk of diabetes compared with women who had had one live birth.

Conclusion

Multiparity was associated with increasing risk of diabetes in this population of Chinese women. These findings suggested that multiparity may be a risk factor for the development of diabetes among Chinese women. Future studies are needed to examine the physiological changes during pregnancy for risk of diabetes in later life.     

Effects of Maternal Pregnancy Intention,Depressive Symptoms and Social Support on Risk of Low Birth Weight: A Prospective Study from Southwestern Ethiopia

Background

Low birth weight (LBW) is the principal risk factor for neonatal and infant mortality in developing countries. This study examines the effects of unwanted pregnancy, prenatal depression and social support on the risk of low birth weight in rural southwestern Ethiopia. We hypothesized that unwanted pregnancy and prenatal depression increase the risk of low birth weight, while social support mediates this association.

Methods

Data for the study comes from a prospective study in which women were followed from pregnancy through to delivery. Six hundred twenty two women were followed and 537 birth weights were measured within 72 hours. Multivariable log binomial regression was used to model the risk of low birth weight.

Results

The mean birth weight was 2989 grams (SD±504 grams), and the incidence of LBW was 17.88%. The mean birth weight of babies after unwanted pregnancy was 114 g lower compared to births from intended pregnancy. Similarly, mean birth weight for babies among women with symptoms of antenatal depression was 116 grams lower. Results of unadjusted log-binomial regression showed that unwanted pregnancy, prenatal depression and social support were associated with LBW. The relationship between antenatal depressive symptoms and LBW was mediated by the presence of social support, while the association between LBW and unwanted pregnancy remained after multivariable adjustment.

Conclusion

The incidence of low birth weight is high in the study area. Poverty, nonuse of antenatal care, low social support and unwanted pregnancy contribute to this high incidence of low birth weight. Hence, identifying women’s pregnancy intention during antenatal care visits, and providing appropriate counseling and social support will help improve birth outcomes.     

Maternal and Perinatal Outcomes of Twin Pregnancy in 23 Low- and Middle-Income Countries

Background

Twin pregnancies in low- and middle-income countries (LMICs) pose a high risk to mothers and newborns due to inherent biological risks and scarcity of health resources. We conducted a secondary analysis of the WHO Global Survey dataset to analyze maternal and perinatal outcomes in twin pregnancies and factors associated with perinatal morbidity and mortality in twins.

Methods

We examined maternal and neonatal characteristics in twin deliveries in 23 LMICs and conducted multi-level logistic regression to determine the association between twins and adverse maternal and perinatal outcomes.

Results

279,425 mothers gave birth to 276,187 (98.8%) singletons and 6,476 (1.2%) twins. Odds of severe adverse maternal outcomes (death, blood transfusion, ICU admission or hysterectomy) (AOR 1.85, 95% CI 1.60–2.14) and perinatal mortality (AOR 2.46, 95% CI 1.40–4.35) in twin pregnancies were higher, however early neonatal death (AOR 2.50, 95% CI 0.95–6.62) and stillbirth (AOR 1.22, 95% CI 0.58–2.57) did not reach significance. Amongst twins alone, maternal age <18, poor education and antenatal care, nulliparity, vaginal bleeding, non-cephalic presentations, birth weight discordance >15%, born second, preterm birth and low birthweight were associated with perinatal mortality. Marriage and caesarean section were protective.

Conclusions

Twin pregnancy is a significant risk factor for maternal and perinatal morbidity and mortality in low-resource settings; maternal risk and access to safe caesarean section may determine safest mode of delivery in LMICs. Improving obstetric care in twin pregnancies, particularly timely access to safe caesarean section, is required to reduce risk to mother and baby.     

Change in Body Size and Mortality: Results from the Melbourne Collaborative Cohort Study

Background

The association between change in weight or body mass index, and mortality is widely reported, however, both measures fail to account for fat distribution. Change in waist circumference, a measure of central adiposity, in relation to mortality has not been studied extensively.

Methods

We investigated the association between mortality and changes in directly measured waist circumference, hips circumference and weight from baseline (1990–1994) to wave 2 (2003–2007) in a prospective cohort study of people aged 40–69 years at baseline. Cox regression, with age as the time metric and follow-up starting at wave 2, adjusted for confounding variables, was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for change in body size in relation to mortality from all causes, cardiovascular disease and cancer.

Results

There were 1465 deaths (109 cancer, 242 cardiovascular disease) identified during an average 7.7 years of follow-up from 21 298 participants. Compared to minimal increase in body size, loss of waist circumference (HR: 1.26; 95% CI: 1.09–1.47), weight (1.80; 1.54–2.11), or hips circumference (1.35; 1.15–1.57) were associated with an increased risk of all-cause mortality, particularly for older adults. Weight loss was associated with cardiovascular disease mortality (2.40; 1.57–3.65) but change in body size was not associated with obesity-related cancer mortality.

Conclusion

This study confirms the association between weight loss and increased mortality from all-causes for older adults. Based on evidence from observational cohort studies, weight stability may be the recommended option for most adults, especially older adults.     

Changes in Association between Previous Therapeutic Abortion and Preterm Birth in Scotland, 1980 to 2008: A Historical Cohort Study

Background

Numerous studies have demonstrated that therapeutic termination of pregnancy (abortion) is associated with an increased risk of subsequent preterm birth. However, the literature is inconsistent, and methods of abortion have changed dramatically over the last 30 years. We hypothesized that the association between previous abortion and the risk of preterm first birth changed in Scotland between 1 January 1980 and 31 December 2008.

Methods and Findings

We studied linked Scottish national databases of births and perinatal deaths. We analysed the risk of preterm birth in relation to the number of previous abortions in 732,719 first births (≥24 wk), adjusting for maternal characteristics. The risk (adjusted odds ratio [95% CI]) of preterm birth was modelled using logistic regression, and associations were expressed for a one-unit increase in the number of previous abortions. Previous abortion was associated with an increased risk of preterm birth (1.12 [1.09–1.16]). When analysed by year of delivery, the association was strongest in 1980–1983 (1.32 [1.21–1.43]), progressively declined between 1984 and 1999, and was no longer apparent in 2000–2003 (0.98 [0.91–1.05]) or 2004–2008 (1.02 [0.95–1.09]). A statistical test for interaction between previous abortion and year was highly statistically significant (p<0.001). Analysis of data for abortions among nulliparous women in Scotland 1992–2008 demonstrated that the proportion that were surgical without use of cervical pre-treatment decreased from 31% to 0.4%, and that the proportion of medical abortions increased from 18% to 68%.

Conclusions

Previous abortion was a risk factor for spontaneous preterm birth in Scotland in the 1980s and 1990s, but the association progressively weakened and disappeared altogether by 2000. These changes were paralleled by increasing use of medical abortion and cervical pre-treatment prior to surgical abortion. Although it is plausible that the two trends were related, we could not test this directly as the data on the method of prior abortions were not linked to individuals in the cohort. However, we speculate that modernising abortion methods may be an effective long-term strategy to reduce global rates of preterm birth. Please see later in the article for the Editors'' Summary     

Adverse Obstetric and Perinatal Outcomes following Treatment of Adolescent and Young Adult Cancer: A Population-Based Cohort Study

Objective

To investigate obstetric and perinatal outcomes among female survivors of adolescent and young adult (AYA) cancers and their offspring.

Methods

Using multivariate analysis of statewide linked data, outcomes of all first completed pregnancies (n = 1894) in female survivors of AYA cancer diagnosed in Western Australia during the period 1982–2007 were compared with those among females with no cancer history. Comparison pregnancies were matched by maternal age-group, parity and year of delivery.

Results

Compared with the non-cancer group, female survivors of AYA cancer had an increased risk of threatened abortion (adjusted relative risk 2.09, 95% confidence interval 1.51–2.74), gestational diabetes (2.65, 2.08–3.57), pre-eclampsia (1.32, 1.04–1.87), post-partum hemorrhage (2.83, 1.92–4.67), cesarean delivery (2.62, 2.22–3.04), and maternal postpartum hospitalization>5 days (3.01, 1.72–5.58), but no excess risk of threatened preterm delivery, antepartum hemorrhage, premature rupture of membranes, failure of labor to progress or retained placenta. Their offspring had an increased risk of premature birth (<37 weeks: 1.68, 1.21–2.08), low birth weight (<2500 g: 1.51, 1.23–2.12), fetal growth restriction (3.27, 2.45–4.56), and neonatal distress indicated by low Apgar score (<7) at 1 minute (2.83, 2.28–3.56), need for resuscitation (1.66, 1.27–2.19) or special care nursery admission (1.44, 1.13–1.78). Congenital abnormalities and perinatal deaths (intrauterine or ≤7 days of birth) were not increased among offspring of survivors.

Conclusion

Female survivors of AYA cancer have moderate excess risks of adverse obstetric and perinatal outcomes arising from subsequent pregnancies that may require additional surveillance or intervention.     

Anthropometric Measurements: Options for Identifying Low Birth Weight Newborns in Kumasi,Ghana

Background

In Ghana, 32% of deliveries take place outside a health facility, and birth weight is not measured. Low birth weight (LBW) newborns who are at increased risk of death and disability, are not identified; 13%–14% of newborns in Ghana are LBW. We aimed at determining whether alternative anthropometrics could be used to identify LBW newborns when weighing scales are not available to measure birth weight.

Methods

We studied 973 mother and newborn pairs at the Komfo Anokye Teaching and the Suntreso Government hospitals between November 2011 and October 2012. We used standard techniques to record anthropometric measurements of newborns within 24 hours of birth; low birth weight was defined as birth weight <2.5kg. Pearson''s correlation coefficient and the area under the curve were used to determine the best predictors of low birth weight. The sensitivity, specificity and predictive values were reported with 95% confidence intervals at generated cut-off values.

Results

One-fifth (21.7%) of newborns weighed less than 2.5 kg. Among LBW newborns, the following measurements had the highest correlations with birth weight: chest circumference (r = 0.69), mid-upper arm circumference (r = 0.68) and calf circumference (r = 0.66); the areas under the curves of these three measurements demonstrated the highest accuracy in determining LBW newborns. Chest, mid-upper arm and calf circumferences at cut-off values of ≤29.8 cm, ≤9.4 cm and ≤9.5 cm respectively, had the best combination of maximum sensitivity, specificity and predictive values for identifying newborns with LBW.

Conclusions

Anthropometric measurements, such as the chest circumference, mid-upper arm circumference and calf circumference, offer an opportunity for the identification of and subsequent support for LBW newborns in settings in Ghana, where birth weights are not measured by standardized weighing scales.     

White matter and cognition in adults who were born preterm

Background and Purpose

Individuals born very preterm (before 33 weeks of gestation, VPT) are at risk of damage to developing white matter, which may affect later cognition and behaviour.

Methods

We used diffusion tensor MRI (DT-MRI) to assess white matter microstructure (fractional anisotropy; FA) in 80 VPT and 41 term-born individuals (mean age 19.1 years, range 17–22, and 18.5 years, range17–22 years, respectively). VPT individuals were part of a 1982–1984 birth cohort which had been followed up since birth; term individuals were recruited by local press advertisement. General intellectual function, executive function and memory were assessed.

Results

The VPT group had reduced FA in four clusters, and increased FA in four clusters relative to the Term group, involving several association tracts of both hemispheres. Clusters of increased FA were associated with more severe neonatal brain injury in the VPT group. Clusters of reduced FA were associated with lower birth weight and perinatal hypoxia, and with reduced adult cognitive performance in the VPT group only.

Conclusions

Alterations of white matter microstructure persist into adulthood in VPT individuals and are associated with cognitive function.     

Childhood growth, IQ and education as predictors of white blood cell telomere length at age 49-51 years: the Newcastle Thousand Families Study

Background

Telomere length is emerging as a potential factor in the pathogenesis of cardiovascular disease. We investigated whether birth weight, infant growth, childhood cognition and adult height, as well as a range of lifestyle, socio-economic and educational factors, were associated with white blood cell telomere length at age 49–51 years.

Methods

The study included 318 members of the Newcastle Thousand Families Study, a prospectively followed birth cohort which includes all individuals born in Newcastle, England in May and June 1947, who attended for clinical examination at age 49–51 years, and had telomere length successfully measured using real-time PCR analyses of DNA extracted from peripheral blood mononuclear cells.

Results

No association was found between birth weight and later telomere length. However, associations were seen with other factors from early life. Education level was the only predictor in males, while telomere length in females was associated with gestational age at birth, childhood growth and childhood IQ.

Conclusions

While these findings may be due to chance, in particular where differing associations were seen between males and females, they do provide evidence of early life associations with telomere length much later in life. Our findings of sex differences in the education association may reflect the sex differences in achieved education levels in this generation where few women went to university regardless of their intelligence. Our findings do not support the concept of telomere length being on the pathway between very early growth and later disease risk.