Risk Of Small-for-gestational-age Birth Research Articles

Gestational weight gain during the second and third trimesters and adverse pregnancy outcomes, results from a prospective pregnancy cohort in urban Tanzania

BackgroundAppropriate gestational weight gain (GWG) is important for optimal pregnancy outcomes. This study prospectively evaluated the associations between GWG during the second and third trimesters of pregnancy and adverse pregnancy outcomes in an urban Tanzanian pregnancy cohort.MethodsWe used data from a randomized clinical trial conducted among pregnant women recruited by 27 weeks of gestation in Dar es Salaam, Tanzania (N = 1230). Women’s gestational weight was measured at baseline and at monthly antenatal visits. Weekly GWG rate during the second and third trimesters was calculated and characterized as inadequate, adequate, or excessive, in conjunction with measured or imputed early-pregnancy BMI status according to the 2009 Institute of Medicine (IOM) GWG guidelines. We used multivariable Poisson regression with a sandwich variance estimator to calculate risk ratios (RR) for associations of GWG with low birth weight, preterm birth, small for gestational age (SGA), and large for gestational age (LGA). Degree of appropriate GWG defined using additional metrics (i.e., percentage of adequacy, z-score) and potential effect modification by maternal BMI were additionally evaluated.ResultsAccording to the IOM guidelines, 517 (42.0%), 270 (22.0%), and 443 (36.0%) women were characterized as having inadequate, adequate, and excessive GWG, respectively. Overall, compared to women with adequate GWG, women with inadequate GWG had a lower risk of LGA births (RR = 0.54, 95% CI: 0.36–0.80) and a higher risk of SGA births (RR = 1.32, 95% CI: 0.95–1.81). Women with inadequate GWG as defined by percentage of GWG adequacy had a higher risk of LBW (OR = 1.93, 95% CI: 1.03–3.63). In stratified analyses by early-pregnancy BMI, excessive GWG among women with normal BMI was associated with a higher risk of preterm birth (RR = 1.59, 95% CI: 1.03–2.44).ConclusionsA comparatively high percentage of excessive GWG was observed among healthy pregnant women in Tanzania. Both inadequate and excessive GWGs were associated with elevated risks of poor pregnancy outcomes. Future studies among diverse SSA populations are warranted to confirm our findings, and clinical recommendations on optimal GWG should be developed to promote healthy GWG in SSA settings.Trial registration: This trial was registered as “Prenatal Iron Supplements: Safety and Efficacy in Tanzania” (NCT01119612; http://clinicaltrials.gov/show/NCT01119612).

Vitamin D3 supplementation during pregnancy and lactation for women living with HIV in Tanzania: A randomized controlled trial.

BackgroundObservational studies suggest that vitamin D deficiency among people living with HIV is associated with a greater risk of disease progression and death. Low levels of vitamin D in pregnancy are also associated with poor fetal and infant growth. Therefore, vitamin D supplementation may improve clinical outcomes for pregnant women living with HIV and improve fetal and postnatal growth for their infants.Methods and findingsWe conducted a randomized, triple-blind, placebo-controlled trial of vitamin D3 supplementation among pregnant and lactating women living with HIV in Dar es Salaam, Tanzania (ClinicalTrials.gov NCT02305927). Participants were randomized with 1:1 allocation stratified by study clinic to receive either daily 3,000 IU vitamin D3 supplements or matching placebo supplements from the second trimester of pregnancy (12–27 weeks) until 1 year postpartum. The primary outcomes were (i) maternal HIV progression or death, (ii) small-for-gestational-age (SGA) live births (<10th percentile), and (iii) infant stunting at 1 year of age (length-for-age z-score < −2). We also examined the effect of vitamin D3 supplementation on secondary maternal and infant health outcomes, maternal and infant serum 25-hydroxyvitamin D (25[OH]D) concentrations, and maternal hypercalcemia. An intent-to-treat analysis was used as the primary analytic approach. We enrolled 2,300 pregnant women between June 15, 2015, and April 17, 2018, and follow-up of mothers and infants was completed on October 20, 2019. There were 1,148 pregnant women randomly assigned to the vitamin D3 group, and 1,152 to the placebo group. The proportion of mothers lost to follow-up at 1 year postpartum was 6.6% in the vitamin D3 group (83 of 1,148) and 6.6% in the placebo group (76 of 1,152). The proportion of children lost to follow-up at 1 year of age was 5.5% in the vitamin D3 group (59 of 1,074 live births) and 5.2% in the placebo group (57 of 1,093 live births). There was no difference in the risk of maternal HIV progression or death, with 166 events during 1,461 person-years of follow-up in the vitamin D3 group and 141 events during 1,469 person-years of follow-up in the placebo group (hazard ratio 1.21, 95% CI 0.97 to 1.52, p = 0.09). There was no difference in the risk of SGA birth between the vitamin D3 (229 SGA births among 1,070 live births) and placebo groups (236 SGA births among 1,091 live births) (relative risk 1.03, 95% CI 0.87 to 1.22, p = 0.70). There was also no difference in the risk of infant stunting at 1 year of age between the vitamin D3 (407 events among 867 infants) and placebo groups (413 events among 873 infants) (relative risk 1.00, 95% CI 0.92 to 1.10, p = 0.95). In terms of adverse events, no cases of maternal hypercalcemia were identified. One hypersensitivity reaction to the trial supplements occurred for a pregnant woman in the placebo group. A limitation of our study is that our findings may not be generalizable to HIV-negative pregnant women or contexts where severe vitamin D deficiency is prevalent.ConclusionsThe trial findings do not support routine vitamin D supplementation for pregnant and lactating women living with HIV in Tanzania.Trial registrationClinicalTrials.gov Identifier: NCT02305927.

Gestational weight gain rates in the first and second trimesters are associated with small for gestational age among underweight women: a prospective birth cohort study

BackgroundDespite the well-studied effects of gestational weight gain (GWG) on offspring health, little is known about the association of trimester-specific GWG with offspring birth weight among underweight pregnant women. This study aimed to explore the association of trimester-specific GWG rate with small for gestational age (SGA) in underweight women.MethodsThe GWG rate of underweight pregnant women (pre-pregnancy body mass index [BMI] lower than 18.5 kg/m2) of the Born in Guangzhou Cohort Study was calculated as the weight gain during a specific trimester divided by the corresponding duration of week. Total GWG was calculated as the weight difference between pre-pregnancy and delivery, and was categorized into inadequate, adequate, and excessive weight gain based on the 2009 Institute of Medicine (IOM) weight gain recommendation. The INTERGROWTH-21st standards were used to define SGA. Logistic regression models were used to examine the associations of total GWG and trimester-specific GWG rates with SGA. Associations between trimester-specific GWG rates and SGA were also analyzed separately based on different total GWG categories (i.e. inadequate and adequate/excessive GWG).ResultsOf the 3839 participants, SGA births occurred in 397 (10.3%), and mean GWG was 14.9 kg (SD 3.9). A lower risk of SGA was observed among women with higher GWG rate (per 0.5 kg/week increase) during the first (adjusted OR [aOR] 0.74, 95%CI 0.57, 0.96) and second (adjusted OR [aOR] 0.40, 95%CI 0.30, 0.55) but not third trimester. Similar association between higher GWG rate during the second trimester and a decreased risk of SGA were observed among women with inadequate (< 12.5 kg) and adequate/excessive (≥12.5 kg) total GWG, respectively. Compared to women with adequate GWG rate, women with inadequate GWG rate during the second trimester had a significantly increased risk of SGA (aOR 1.58, 95% CI 1.14, 2.20).ConclusionsSecond-trimester GWG might be the key driver for the association between inadequate GWG and increased risk of SGA births in underweight women.

Maternal smoking behaviour across the first two pregnancies and small for gestational age birth: Analysis of the SLOPE (Studying Lifecourse Obesity PrEdictors) population-based cohort in the South of England.

Maternal smoking is established to cause adverse birth outcomes, but evidence considering maternal smoking change across successive pregnancies is sparse. We examined the association between self-reported maternal smoking during and between the first two pregnancies with the odds of small for gestational age (SGA) birth (<10th percentile) in the second infant. Records for the first two pregnancies for 16791 women within the SLOPE (Studying Lifecourse Obesity PrEdictors) study were analysed. This is a population-based cohort of prospectively collected anonymised antenatal and birth healthcare data (2003-2018) in Hampshire, UK. Logistic regression was used to relate maternal smoking change to the odds of SGA birth in the second infant. In the full sample, compared to never smokers, mothers smoking at the start of the first pregnancy had higher odds of SGA birth in the second pregnancy even where they stopped smoking before the first antenatal appointment for the second pregnancy (adjusted odds ratio (aOR) 1.50 [95% confidence interval 1.10, 2.03]). If a mother was not a smoker at the first antenatal appointment for either her first or her second pregnancy, but smoked later in her first pregnancy or between pregnancies, there was no evidence of increased risk of SGA birth in the second pregnancy compared to never smokers. A mother who smoked ten or more cigarettes a day at the start of both of her first two pregnancies had the highest odds of SGA birth (3.54 [2.55, 4.92]). Women who were not smoking at the start of the first pregnancy but who subsequently resumed/began smoking and smoked at the start of their second pregnancy, also had higher odds (2.11 [1.51, 2.95]) than never smokers. Smoking in the first pregnancy was associated with SGA birth in the second pregnancy, even if the mother quit by the confirmation of her second pregnancy.

P–773 Infertility treatment and the risk of small for gestational age births: a population-based study in the United States

Abstract Study question What is the association between infertility treatments and small for gestational age (SGA) births? Summary answer Women who conceived pregnancies with any infertility treatment had a decreased risk of SGA &amp;lt;10th, &amp;lt;5th and &amp;lt;3rd percentiles compared to naturally conceived pregnancies. What is known already Assisted reproductive technology (ART) and other infertility treatments have long been associated with an increased risk of SGA births, which confers a greater risk of perinatal morbidity and mortality compared to appropriate for gestational age births. Study design, size, duration This is a cross-sectional study of 16,836,228 births in the United States (US) between 2015–2019. The exposure group included women who underwent any infertility treatment, including ART and prescribed fertility enhancing medications. The comparison group included those who had naturally conceived pregnancies. The primary outcome was SGA birth, defined as sex-specific birthweight &amp;lt;10th percentile for gestational age. Secondary outcomes included SGA &amp;lt;5th and &amp;lt;3rd percentile births. Participants/materials, setting, methods Pregnant subjects (n = 16,836,228) in the US who delivered non-malformed, singleton live births between 24–44 weeks’ gestational age. We estimated risk of SGA births in relation to any infertility treatment from fitting log-linear Poisson regression models with robust variance. Risk ratios (RR) and 95% confidence intervals (CI) were estimated as the effect measure before and after adjusting for confounders. We also performed a sensitivity analysis to correct for potential non-differential exposure misclassification and unmeasured confounding biases. Main results and the role of chance During the study period, 1.4% (n = 231,177) of non-malformed singleton live births resulted from infertility treatments (0.8% ART and 0.6% fertility enhancing medications). Of these, 9.4% (n = 21,771) of pregnancies conceived with infertility treatment were complicated by SGA &amp;lt;10th percentile compared to 11.9% (n = 1,755,925) of naturally conceived pregnancies. For pregnancies conceived with infertility treatment versus naturally conceived pregnancies, the adjusted RR for SGA &amp;lt;10th percentile was 1.07 (95% CI 1.06, 1.08). However, after correction for misclassification bias and unmeasured confounding, infertility treatment was found to be protective for SGA and conferred a 27% reduced risk of SGA &amp;lt;10th percentile (bias-corrected RR 0.73, 95% CI 0.53, 0.85). These trends were similar for analyses stratified by exposure to ART and fertility enhancing medications and secondary SGA outcomes, including SGA &amp;lt;5th and &amp;lt;3rd percentile. Limitations, reasons for caution All information collected on infertility treatment relies on self-reporting by patients and recording by hospital staff at the time of delivery, which likely resulted in underreporting of infertility treatments. Additionally, we cannot determine the impact of interventions that were not recorded, such as intrauterine insemination (IUI). Wider implications of the findings: Compared to naturally conceived pregnancies, exposure to infertility treatment is associated with reduction in the risk of SGA births. These findings, which are contrary to some published reports, likely reflect changes in the modern practice of infertility care in the US, and importantly, robust analysis of the national data. Trial registration number Not applicable

Factors associated with sub-microscopic placental malaria and its association with adverse pregnancy outcomes among HIV-negative women in Dar es Salaam, Tanzania: a cohort study

BackgroundMalaria infection during pregnancy has negative health consequences for both mothers and offspring. Sub-microscopic malaria infection during pregnancy is common in most African countries. We sought to identify factors associated with sub-microscopic placental malaria, and its association with adverse pregnancy outcomes among HIV-negative pregnant women in Dar es Salaam, Tanzania.MethodsWe recruited a cohort of pregnant women during their first trimester and assessed for the occurrence of placental malaria and pregnancy outcomes. The follow-up was done monthly from recruitment until delivery. Histopathology placental malaria positive results were defined as the presence of malaria pigment or parasitized erythrocytes on the slide (histology-positive (HP)), and the sub-microscopic placental infection was defined as positive Plasmodium falciparum DNA by polymerase chain reaction (DNA PCR) amplification in a negative histopathology test. Adverse pregnancy outcomes investigated included low birth weight (birth weight below 2.5 kg), prematurity (live birth below 37 weeks), and small-for-gestational-age (SGA) (live born with a birth weight below 10th percentile for gestational age and sex). Weighted baseline category logit, log-binomial, and log-Poisson models were used to assess factors associated with placental malaria, and its association with adverse pregnancy outcomes.ResultsAmong 1115 women who had histopathology and DNA PCR performed, 93 (8%) had HP placental infection, and 136 (12%) had the sub-microscopic placental infection. The risk of sub-microscopic placental malaria was greater in women who did not use mosquito prevention methods such as bed nets, fumigation, or mosquito coils (odds ratio (OR) = 1.75; 95% confidence interval (CI): 1.05–2.92; P = 0.03) and in women who were anemic (OR = 1.59; 95% CI: 1.20–2.11; P = 0.001). Women who were underweight had reduced odds of sub-microscopic placental malaria infection (OR = 0.33; 95% CI: 0.17–0.62; P = 0.001). Women who were overweight/obese had 1.48 times higher the odds of HP placental malaria compared to normal weight (OR = 1.48; 95% CI: 1.03–2.11; P = 0.03). HP placental malaria infection was associated with an increased risk of SGA births (RR = 1.30, 95% CI: 0.98–1.72, P = 0.07). In contrast, the sub-microscopic infection was associated with a reduced risk of SGA births (RR = 0.61, 95% CI: 0.43–0.88, P = 0.01). Placental malaria was not associated with low birth weight or prematurity.ConclusionMalaria prevention methods and maternal nutrition status during early pregnancy were important predictors of sub-microscopic placental malaria. More research is needed to understand sub-microscopic placental malaria and the possible mechanisms mediating the association between placental malaria and SGA.

Maternal exposure to low-to-medium altitude and birth outcomes: evidence from a population-based study in Chinese newborns.

Despite high altitude was implicated in adverse birth outcomes, there remained a paucity of evidence on low-to-medium altitude effect. This study aimed to explore the association of low-to-medium altitude with birth outcomes. A population-based cross-sectional survey was performed using a stratified multistage random sampling method among women with their infants born during 2010-2013 in Northwestern China. Altitude was determined in meters based on the village or community of the mother's living areas. Birth outcomes involved birth weight, gestational age, and small for gestational age (SGA). Generalized linear models were fitted to investigate the association of altitude with birth outcomes. Moreover, the dose-response relationship between altitude and birth outcomes was evaluated with a restricted cubic spline function. A total of 27 801 women with their infants were included. After adjusting for potential confounders, every 100-m increase in the altitude was associated with reduced birth weight by 6.4 (95% CI -8.1, -4.6) g, the slight increase of gestational age by 0.015 (95% CI 0.010, 0.020) week, and an increased risk of SGA birth (odds ratio 1.03, 95% CI 1.02, 1.04). Moreover, there was an inversely linear relationship between altitude and birth weight (P for overall < 0.001 and P for nonlinear = 0.312), and a positive linear relationship between altitude and SGA (P for overall < 0.001 and P for nonlinear = 0.194). However, a nonlinear relationship was observed between altitude and gestational age (P for overall < 0.001 and P for nonlinear = 0.010). The present results suggest that low-to-medium altitude is possibly associated with adverse birth outcomes.

Maternal arsenic exposure and birth outcomes: A birth cohort study in Wuhan, China.

Maternal arsenic exposure leads to adverse birth outcomes, but the critical window of this susceptibility keeps unclear. To determine whether the associations between maternal arsenic exposure and birth outcomes were trimester-specific, we conducted a birth cohort study of 1390 women from 2014 to 2016 in Wuhan, China. We examined associations between total urinary arsenic concentrations in three trimesters and birth weight, birth length and the risk of small for gestational age (SGA), and the differences of these associations across trimesters using generalized estimating equations. Maternal urinary arsenic concentrations varied across trimesters and were weakly correlated. Arsenic concentrations in the 3rd trimester, but not in the 1st and 2nd trimesters, were associated with birth outcomes. For each doubling of arsenic levels in the 3rd trimester, birth weight was decreased 24.27 g (95% confidence interval (CI):-46.99,-1.55), birth length was decreased 0.13 cm (95% CI:-0.22,-0.04), and the risk for SGA birth was increased 25% (95% CI: 1.03, 1.49). Further, stratified analyses indicated that these associations were only observed in female infants. Our findings indicate maternal arsenic levels in the 3rd trimester seemed to have significant impacts on birth outcomes, and also emphasize the public health interventions relevance to arsenic exposure in late pregnancy.

Living in violence: Neighborhood domestic violence and small for gestational age births

ObjectivesTo determine the association between neighborhood domestic violence and small-for-gestational-age (SGA) birth and to examine if there is a differential impact of neighborhood domestic violence on SGA births by race in a high crime community. MethodsThis analysis includes all birth records issued in New Orleans, Louisiana from 2011 to 2012 geocoded by census tract (N=177 census tracts, N=8322 women). Hierarchical modeling and ecologic spatial analysis were used to examine the area-effect of neighborhood domestic violence on SGA births, independent of individual-level predictors and accounting for the propensity to live in high domestic violence neighborhoods. ResultsTests for spatial autocorrelation reveled area-level clustering and overlap of SGA and domestic violent rates. Pregnant women living in high domestic violence areas were more likely to give birth to an SGA infant compared to women in low-domestic violence areas (OR=1.04, 95%CI: 1.01, 1.08), net of the effects of individual-level factors and propensity scores. ConclusionNeighborhood-level attributes including rates of domestic violence may increase women's risk for SGA birth, highlighting a policy-relevant and potentially amenable exposure.

Small-for-Gestational-Age Birth and Maternal Plasma Antioxidant Levels in Mid-Gestation: A Nested Case-Control Study

(BJOG. 2015;122:1313–1321) This is one of only a few prospective studies to assess antioxidant levels during pregnancy and the risk of small-for-gestational-age (SGA) birth. It includes the largest number of cases and most comprehensive set of antioxidants measured in studies published to date. The aim of the study was to prospectively measure a broad panel of maternal plasma antioxidant biomarker levels in mid-pregnancy and assess their association with the risk of SGA birth. It is hypothesized that higher levels of antioxidants in maternal blood may provide some protection from SGA birth.

Prehypertension in Pregnancy and Risks of Small for Gestational Age Infant and Stillbirth.

It is not fully known whether maternal prehypertension is associated with increased risk of adverse fetal outcomes, and it is debated whether increases in blood pressure during pregnancy influence adverse fetal outcomes. We performed a population-based cohort study in nonhypertensive women with term (≥37 weeks) singleton births (n=157 446). Using normotensive (diastolic blood pressure [DBP] <80 mm Hg) women as reference, we calculated adjusted odds ratios with 95% confidence intervals between prehypertension (DBP 80-89 mm Hg) at 36 gestational weeks (late pregnancy) and risks of a small-for-gestational-age (SGA) birth or stillbirth. We further estimated whether an increase in DBP from early to late pregnancy affected these risks. We found that 11% of the study population had prehypertension in late pregnancy. Prehypertension was associated with increased risks of both SGA birth and stillbirth; adjusted odds ratios (95% confidence intervals) were 1.69 (1.51-1.90) and 1.70 (1.16-2.49), respectively. Risks of SGA birth in term pregnancy increased by 2.0% (95% confidence intervals 1.5-2.8) per each mm Hg rise in DBP from early to late pregnancy, whereas risk of stillbirth was not affected by rise in DBP during pregnancy. We conclude that prehypertension in late pregnancy is associated with increased risks of SGA birth and stillbirth. Risk of SGA birth was also affected by rise in DBT during pregnancy. Our findings provide new insight to the relationship between maternal blood pressure and fetal well-being and suggest that impaired maternal perfusion of the placenta contribute to SGA birth and stillbirth.

Hair Biomarkers as Measures of Maternal Tobacco Smoke Exposure and Predictors of Fetal Growth

Most biomarker studies of the effects of maternal smoking on fetal growth have been based on a single blood or urinary cotinine value, which is inadequate in capturing maternal tobacco exposure over the entire pregnancy. We used hair biomarkers to compare the associations of maternal self-reported smoking, hair nicotine, and hair cotinine with birth weight for gestational age (BW for GA) among active and passive smokers during pregnancy. We collected maternal hair in the immediate postpartum period and measured nicotine and cotinine concentrations averaged over the pregnancy in 444 term controls drawn from 5,337 participants in a multicenter nested case-control study of preterm birth. BW for GA Z-score and small for gestational age (SGA) were based on Canadian population-based standards. The addition of hair nicotine to multiple linear regression models containing self-reported active smoking, hair cotinine, or both explained significantly more variance in the BW for GA Z-score (p = .01, .03 and .04, respectively). Similarly, women with hair nicotine, but not cotinine, at or above the median value had a significant increase in the risk of SGA birth (odds ratio: 3.07, 95% CI: 1.25-7.52). No significant association was observed between maternal passive smoking and BW for GA based on hair biomarkers. Hair nicotine is a better predictor of reductions in BW for GA than either hair cotinine or self-report. Our negative results for passive smoking suggest that previously reported small but significant effects may be explained by misclassification of active smokers as passive smokers based on self-report.

Maternal Cardiovascular Disease Risk in Relation to the Number of Offspring Born Small for Gestational Age: National, Multigenerational Study of 2.7 Million Births

A number of studies have found an association between low birth weight or fetal growth impairment and an increased risk of hypertension, type 2 diabetes, and cardiovascular disease (CVD) in adult life. This interaction may be due to nutritional and lifestyle-related factors during pregnancy or genetic factors. Other studies reported a similar interaction but were limited by sample size and did not include nonfatal events and adjustment for social background (educational level). This large, national, observational study assessed the risk of small for gestational age (SGA) births in relation to maternal history of CVD across 2 generations. Data for 1.4 million women and 2.7 million offsprings were obtained for the years 1973 to 2004 from the Swedish national, multigeneration register and analyzed. The primary outcome measure was determination of the risk of being SGA in relation to maternal history of CVD (n = 10,436) across 2 generations. Secondary outcomes included determination of the risk of maternal CVD based on number of SGA births and assessment of the possible contribution of level of education for these associations. For both male and female offspring with a positive maternal history of CVD, the risk of being SGA was higher than for offspring with no family history of CVD (reference); the hazard ratio (HR) for females was 1.11, with a 95% confidence interval (CI), of 1.09-1.13), and for males it was 1.12 (1.09-1.14). A 2 generation history of CVD (in both mother and grandmother) was associated with the highest risk (for girls, HR: 1.32, 95% CI: 1.24-1.39 and for boys, 1.43, 1.35-1.51 ). Compared to women with no SGA infants, the risk of a maternal history of CVD increased along with the number of SGA offspring (1 SGA, HR: 1.41, 95% CI: 1.36-1.46; 2 SGAs: HR: 1.74, 95% CI: 1.58-1.93; and 3 or more SGAs: HR: 1.86, 95% CI: 1.35-2.57). Among the 3 levels of education evaluated, the interaction between maternal CVD and risk of SGA birth was the strongest in the group with the lowest level of education and increased in a graded manner with 1, 2, and 3 SGAs. These data, based on multigenerational observational epidemiological data, indicate that the risk of SGA offspring is positively related to the occurrence of CVD over 2 generations of mothers, and that risk of maternal CVD is associated with the number of SGA offsprings.

A prospective study of micronutrient status in adolescent pregnancy

Background: Adolescents are more likely than adults to consume energy-dense, micronutrient-poor diets and to experience adverse pregnancy outcomes.Objectives: The objectives were to assess micronutrient intake and blood biomarkers prospectively in pregnant adolescents recruited to the About Teenage Eating (ATE) Study and to determine associations with pregnancy outcome.Design: Pregnant adolescents (n = 500) were recruited from 2 UK inner city populations. Dietary intake was assessed with three 24-h dietary recalls, and micronutrient status was assessed by measurement of third trimester blood biomarkers. Pregnancy outcomes included small-for-gestational age (SGA) birth and preterm delivery.Results: Median iron and folate intakes were lower than UK and US recommended amounts. Folate and vitamin B-12 status were lower in smokers, despite no differences in dietary intake. Serum folate was <7.0 nmol/L in 12% of subjects, and serum total homocysteine (tHcy) was elevated (>10 μmol/L) in 20% of subjects. Fifty-two percent of the subjects had iron deficiency anemia, and 30% had serum 25-hydroxyvitamin D concentrations <25 nmol/L. The incidence of SGA birth was higher in subjects with poorer folate status (red blood cell folate, P = 0.003; serum folate, P = 0.02; tHcy, P = 0.01; simple regression) and those with low folate intakes, regardless of the inclusion (P = 0.021) or exclusion (P = 0.049) of intake from supplements (simple regression). Adjustment for confounding variables confirmed the independence of these associations. The risk of SGA birth was also higher in subjects with low food iron intake (P = 0.049), but not when intake included iron from supplements (P = 0.21). The risk of SGA birth was lower in subjects with iron deficiency anemia (P = 0.002).Conclusion: Poor micronutrient intake and status increase the risk of SGA births in pregnant adolescents.

Maternal fish and shellfish intake and pregnancy outcomes: a prospective cohort study in Brittany, France.

BackgroundRecommendations about risks and benefits of seafood intake during pregnancy have been published in the last decade, but the specific health effects of the different categories of seafood remain unknown. Fish and shellfish may differ according to their fatty acid content and their concentration of chemical pollutants and toxins. Not taking these particularities into account may result in underestimating of both the positive and negative effects of seafood on birth outcomes and partly explains inconsistent results on the subject.MethodsIn the PELAGIE cohort study, including 2398 pregnant women from Brittany, we fit multiple linear and logistic regression models to examine associations of fish (salt-water fish only) and shellfish intake before pregnancy with length of gestation, birthweight, and risks of preterm births, low birthweight or small-for-gestational-age (SGA) babies.ResultsWhen fish and shellfish consumptions were considered simultaneously, we observed a decrease in the risk of SGA birth with increasing frequency of fish intake: OR = 0.57 (95%CI: 0.31 to 1.05) for women eating fish twice a week or more compared with those eating it less than once a month. The risk of SGA birth was significantly higher among women eating shellfish twice a week or more than among those eating it less than once a month: OR = 2.14 (95%CI: 1.13 to 4.07). Each additional monthly meal including fish was significantly related to an increase in gestational length of 0.02 week (95%CI: 0.002 to 0.035). No association was observed with birthweight or preterm birth.ConclusionThese results suggest that different categories of seafood may be differently associated with birth outcomes, fish consumption with increased length of gestation and shellfish consumption with decreased fetal growth.

Induced abortion and risk of small‐for‐gestational‐age birth

To investigate the possibility of an association between previous induced abortion and subsequent birth of a small-for-gestational-age (SGA) infant. Case-control study. General and university hospitals. Cases were 555 women who delivered SGA babies. Controls were 1966 women who gave birth at term (>37 weeks of gestation) to healthy infants of normal weight on randomly selected days at the hospital where cases had been identified. All women in the case and control categories were interviewed on the obstetric wards by one of a team of six interviewers. During the interviews, information was obtained regarding general socio-demographic factors, personal characteristics and habits, gynaecological and obstetric history, general anamnesis, family history of obstetric and gynaecological diseases, and the age of the father of the child. Further information on current pregnancy and delivery was also collected. We used conditional multiple logistic regression (with age as the matching variable), with maximum likelihood fitting, to obtain odds ratios and their corresponding 95% CIs. Included in the regression equations were terms for education, plus terms significantly associated in this data set with the risk of SGA birth (smoking in pregnancy, history of SGA, gestational hypertension and parity). Women admitted to a general and a university hospital. No significant increase in the risk of SGA birth was observed in women with a previous induced abortion [odds ratio (OR) 1.0; 95% CI 0.6-1.7]. The OR for SGA birth was 1.2 (95% CI 0.7-2.1) for preterm and 1.0 (95% CI 0.7-1.4) for term SGA births. This study found no association between risk of SGA birth and induced abortion.

Association between small for gestational age and paternally inherited 5′ insulin haplotypes

To test the association between small for gestational age and polymorphisms in the insulin gene in newborns and their mothers, as well as the effect of the parental transmission of haplotypes. Pairs of healthy African-American full-term newborns (N=207) and mothers were recruited from Memphis TN and Jackson MS with birth weights ranging from 2210 to 4735 g. Six single nucleotide polymorphisms (SNPs) located in the insulin (INS) and insulin-like growth factor 2 (IGF2) genes were genotyped in mothers and newborns. Haplotypes composed of three SNPs in the 5' region of the INS-IGF2 locus were computationally inferred. Odds ratios for risk of small for gestational age (SGA) birth were calculated for individual SNPs and inferred haplotypes in the newborns and in the mothers using logistic regression. For 162 mother--newborn pairs the parental transmission of the haplotypes could be inferred, and the risks for SGA birth were calculated for the three common haplotypes in this sample. Three INS SNPs exhibited significant association with risk for SGA birth. The SNP alleles associated with increased risk for SGA were opposite in the maternal and newborn genomes, implying opposing influences on the rate of fetal growth. Consistent with these results, haplotypes composed of complementary nucleotide sequences (CAC at rs3842738, rs689 and rs3842748, respectively, in the newborn versus GTG in the mother) were significantly associated with risk for SGA birth. In analyses of haplotypes according to parental transmission, the same trend in risk for SGA was observed for both maternally and paternally transmitted haplotypes, although a significant difference in risk was observed only for paternally transmitted haplotypes. Polymorphisms near the 5' end of the INS-IGF2 locus are significantly associated with risk for SGA birth with a major effect due to the paternally transmitted haplotype, which is preferentially expressed due to imprinting.

High caffeine consumption in the third trimester of pregnancy: gender-specific effects on fetal growth.

It has been suggested that a high caffeine intake in pregnancy may be a risk factor for fetal growth retardation. We have tested this hypothesis in a population-based case-control study. Caffeine intake among 111 mothers of small-for-gestational-age (SGA) infants (56 boys, 55 girls) was compared with the intake among 747 mothers of non-SGA infants (368 boys, 379 girls). Food records for 3 days were collected in the second (week 17-20) and in the third (week 33) trimester, and caffeine intake from coffee, tea, soft drinks and chocolate was calculated and dichotomised as low or high, based upon the median value. Mothers of SGA infants had higher mean intake of caffeine [281 +/- 210 (SD) mg/day] in the third trimester than mothers of non-SGA infants (212 +/- 150 mg/day; P < 0.001). The risk of SGA birth was nearly doubled if the mother had a high rather than a low caffeine intake in the third trimester [odds ratio (OR) 1.8; 95% confidence intervals (CI) 1.2, 2.5]. The increased risk was mainly found in boys (OR 2.8; 95% CI 1.5, 5.2), and not in girls (OR 1.2; 95% CI 0.7, 2.1). The increased risk for boys persisted after adjustment for cigarette smoking alone, or for smoking and various other SGA risk factors together. Our results suggest that a high caffeine intake in the third trimester may be a risk factor for fetal growth retardation, in particular if the fetus is a boy.