American Journal of Clinical Nutrition Pregnancy and lactation

Pregnancy outcomes related to gestational weight gain in women defined by their body mass index, parity, height, and smoking status [Pregnancy and lactation]

Nohr, E. A, Vaeth, M., Baker, J. L, Sorensen, T. I., Olsen, J., Rasmussen, K. M — Tue, 20 Oct 2009 10:02:36 PDT

Background: Recommendations for gestational weight gain (GWG) account for a woman's prepregnancy body mass index (BMI), but other factors may be important.

Objectives: The objectives were to investigate whether, within BMI categories, the GWG with the lowest risks to mother and infant varied with parity and to describe these risks in short (<160 cm), young (<20 y), and smoking women.

Design: Of 27,030 primiparous and 31,407 multiparous women with term births within the Danish National Birth Cohort, self-reported GWG was divided into 6 categories (<5, 5–9, 10–15, 16–19, 20–24, and ≥25 kg). Population-based registers provided information about birth outcomes. GWG-specific absolute adjusted risks for emergency cesarean delivery, birth of a small-for-gestational-age (SGA) or large-for-gestational-age (LGA) infant, and postpartum (6 mo) weight retention (PPWR) were compared across different types of women.

Results: The risk of SGA decreased with increasing GWG in both parity groups, but SGA risk <10% was reached at 2–3 GWG categories lower in multiparae than in primiparae. An excess risk of LGA was present only in obese primiparae and multiparae, but the PPWR risk increased with increasing GWG irrespective of BMI and parity. Young primiparae had better outcomes than other primiparae. Short women had a higher risk of emergency cesarean delivery that varied minimally with GWG. Smokers had a higher SGA risk and had a PPWR risk similar to that of nonsmokers.

Conclusions: The tradeoff in risk between mother and infant is reached at lower GWG in multiparae than in primiparae; therefore, a lower GWG may be needed among multiparae. Differential guidelines seem unnecessary for short or young women or smokers.

Periconceptional iron supplementation does not reduce anemia or improve iron status among pregnant women in rural Bangladesh [Pregnancy and lactation]

Khambalia, A. Z, O'Connor, D. L, Macarthur, C., Dupuis, A., Zlotkin, S. H — Tue, 20 Oct 2009 10:02:37 PDT

Background: There is a growing interest in periconceptional iron supplementation in developing countries by researchers and policy makers; however, there are no randomized controlled trials that examine the effectiveness of this strategy in decreasing anemia during pregnancy.

Objective: The aim was to determine whether periconceptional iron supplementation reduces anemia during pregnancy.

Design: A randomized, double-blind, controlled trial was conducted in rural Bangladesh. Married, nulliparous women were randomly assigned to receive daily iron and folic acid (IFA; 60 mg ferrous fumarate and 400 µg folic acid) (n = 134) or folic acid (FA; 400 µg) (n = 138) in the form of a powdered supplement added to food. Women were followed until pregnancy or the end of 9 mo. Primary outcomes included hemoglobin, plasma ferritin, and plasma transferrin receptor concentrations.

Results: Among 88 pregnant women, periconceptional IFA in comparison with FA did not affect anemia or iron status at 15 wk gestation. However, each 1% increase in adherence was associated with a 10-g/L increase in change in hemoglobin from baseline (P = 0.03), and those who initiated supplementation at a mean (±SD) time of 72.9 ± 57.8 d before conception showed a 7.3-g/L increase in change in hemoglobin from baseline compared with those who initiated supplementation at 26.3 ± 12.3 d after conception (P = 0.01). Among 146 nonpregnant women, IFA decreased anemia (odds ratio: 0.19; 95% CI: 0.04, 0.95) and improved iron stores (P = 0.001) more than did FA.

Conclusion: Good adherence and initiation of supplementation before conception are needed to reduce anemia during early pregnancy. This trial was registered at www.clinicaltrials.gov as NCT00953134.

Fish consumption during pregnancy, prenatal mercury exposure, and anthropometric measures at birth in a prospective mother-infant cohort study in Spain [Pregnancy and lactation]

Fri, 18 Sep 2009 13:36:54 PDT

Background: Birth size has been shown to be related to maternal fish intake, although the results are inconsistent.

Objective: The objective was to assess the association of consumption of different types of fish and prenatal mercury exposure with birth weight, birth length, and classification as small for gestational age (SGA) in newborns.

Design: Cord blood total mercury was measured in 554 newborns in a population-based cohort born from 2004 to 2006. Fish consumption was classified in 4 frequency categories (<1 portion/mo, 1–3 portions/mo, 1 portion/wk, and ≥2 portions/wk).

Results: When multivariate models were adjusted, newborns in the higher quartile of total mercury weighed 143.7 g less (95% CI: –251.8, –35.6; P for trend = 0.02) and had higher odds of being SGA for length (odds ratio: 5.3; 95% CI: 1.2, 23.9; P from likelihood ratio test = 0.03) without a linear relation (P for trend = 0.13) compared with those in the lowest quartile. Mothers consuming ≥2 portions/wk of canned tuna had newborns who weighed more than those who consumed <1 portion/mo (P for trend = 0.03) and a lower risk of having infants who were SGA for weight (P for trend = 0.01). Consumption of ≥2 portions/wk of large oily fish was associated with a higher risk of being SGA for weight and consumption of lean fish with a lower risk of being SGA for length compared with the consumption of <1 portion/mo, but in neither case was there a linear relation (P for trend >0.05).

Conclusions: The role of fish in fetal growth depends on the amount and type of fish consumed. The findings for mercury warrant further investigation in other settings.