A recent study by researchers at Princeton University found a higher prevalence of preterm birth among U.S. babies who were conceived in the first part of the year, peaking for May conceptions, and higher average birthweight among babies conceived in June through August. The authors examined natality data on more than 1.4 million singleton births that occurred in New York City, New Jersey, and Pennsylvania at various times during 1997–2010. To control for the potential influence of socioeconomic status on birth outcomes, the researchers analyzed the seasonality of birth by comparing siblings born to the same mother at different times during the study period. Preterm birth was measured in gestational age (weeks) at birth. They found that babies conceived in May had gestations that were shorter by 0.8 weeks, leading to an increase in “premature” births of approximately 1 percentage point. The authors estimate that with an average U.S. premature birth rate of 7.6 percent, the additional percentage point of premature births reflects a 13.2 percent higher occurrence of prematurity among babies conceived in May. With regard to birthweight (grams), after adjusting for several contributing factors, the authors found that babies conceived in the “summer months” (June, July, and August in the United States) had a significantly higher average birthweight compared with babies conceived in other months. On average, babies conceived in the summer weighed about 8 g more than babies conceived at other times of the year. Currie and Schwandt (2013) offer explanations for their findings, including the important influence of influenza-related effects on gestation and seasonal maternal weight gain effects on infant birthweight. They call for continued recommendations that all women obtain influenza vaccinations as a potential means to reduce preterm birth, and for additional research on the effects of such policies.

Source: Currie J, Schwandt H. Within-mother analysis of seasonal patterns in health at birth. Proceedings of the National Academy of Sciences of the United States of America. 2013 July 8. [Epub ahead of print]

A new study has found support for the notion that delays in severing the umbilical cord are beneficial to infants and do not cause harm to mothers. The paper, published recently in The Cochrane Database of Systematic Reviews, indicates that term newborns whose umbilical cords were clamped at least a minute (or more) after birth had higher hemoglobin levels 24–48 hours after birth and were less likely to be iron deficient 3–6 months after birth, as compared with their term counterparts who had early cord clamping. Delayed clamping also affected babies’ birthweight, partly due to receipt of more blood from their mothers, with a higher average birthweight among those whose cords were clamped later. The timing of cord clamping has been controversial, but the new study adds to the growing body of literature suggesting that current practices involve clamping umbilical cords too soon after delivery. The authors also found that delayed cord clamping did not have detrimental effects on mothers, as there was no increased risk of severe postpartum hemorrhage, blood loss, or reduced hemoglobin levels in mothers whose babies’ cords were clamped at least a minute after birth rather than immediately after delivery. The World Health Organization (WHO) recommends that umbilical cords be clamped one to three minutes after delivery to help improve the infant's iron status, although an increased risk of jaundice among later-clamped infants is something the WHO advises providers to prepare for. The Cochrane review found a two percent increase in jaundice among infants who had delayed cord clamping compared with those who did not.

The American College of Obstetricians and Gynecologists (ACOG) reviewed evidence similar to that included in the recent Cochrane review, but found it to be insufficient to confirm or refute potential benefits from delayed umbilical cord clamping in term infants, especially in resource-rich settings. Concerns also have been raised about instances in which cord clamping may not be medically appropriate, such as when a newborn requires resuscitation or aspirates meconium. In addition, the review did not explore the effects of delayed cord clamping in cesarean deliveries. The lead author of the Cochrane review, Dr. Susan McDonald, a professor of midwifery in Melbourne, Australia, acknowledges the limitations of the study, but counters ACOG's recommendations by encouraging delayed cord clamping to give babies a “healthy start” by boosting infants’ iron stores.

Sources: McDonald SJ, Middleton P, Dowswell T, Morris PS. Effect of timing of umbilical cord clamping of term infants on maternal and neonatal outcomes. Cochrane Database of Systematic Reviews. 2013 July 11; 7:CD004074. [Epub ahead of print] PMID: 23843134.

Saint Louis C. Study finds benefits in delaying severing of umbilical cord. New York Times. July 10, 2013.

The burden of small-for-gestational-age births is very high in countries of low and middle income, and is concentrated in south Asia. In a study published in a recent issue of Lancet Global Health, researchers examined national and regional estimates of term and preterm babies born small for gestational age (SGA) in 138 low-income and middle-income countries in 2010. They found that approximately 32.4 million infants were born SGA (defined as lower than the 10th centile for fetal growth from the U.S. national reference population), representing 27 percent of all live births in the countries studied. Among these SGA infants, 10.6 million were born at term, but were of low birthweight (< 2,500 g). Of 18 million low birthweight infants, 59 percent were term SGA. Approximately two thirds of SGA infants were born in Asia, of whom 17.4 million were born in south Asia. Preterm SGA infants comprised 2.8 million births in the study countries in 2010, and most SGA infants were born in India, Pakistan, Nigeria, and Bangladesh. The authors conclude that implementation of effective interventions for babies born too small or too soon is an urgent priority that is needed to increase survival, and to reduce disability, stunting, and noncommunicable diseases.

Source: Lee ACC, Katz J, Blencowe H, et al. National and regional estimates of term and preterm babies born small for gestational age in 138 low-income and middle-income countries in 2010. Lancet Global Health 2013;1:e26–36.

The World Health Organization (WHO) released new HIV treatment guidelines recommending offering antiretroviral therapy (ART) earlier than recommended in the past. According to a WHO news release, the change could avert an additional 3 million deaths and prevent 3.5 million new HIV infections between now and 2025. The new recommendations encourage all countries to initiate treatment in adults living with HIV when their CD4 cell count falls to 500 cells/mm3 or less—when their immune systems are still strong—whereas previous 2010 guidelines suggested offering treatment at 350 CD4 cells/mm3 or less. While 90 percent of all countries adopted the 2010 recommendation, a few countries (Algeria, Argentina, and Brazil) are already offering treatment according to the new recommendations.

The new recommendations also suggest providing ART—irrespective of CD4 count—to all children under 5 years who have HIV, all pregnant and breastfeeding women with HIV, and to all HIV-positive individuals whose partner is not infected. Another new recommendation is that all adults who start taking ART be offered the same daily, single, fixed-dose combination pill. The combination pill is easier to take and is considered safer than alternative combinations previously recommended, and can be used in adults, pregnant women, adolescents, and older children. The recommended treatment is now a combination of three antiretroviral drugs: tenofovir and lamivudine (or emtricitabine) and efavirenz, as a single pill, given once daily.

WHO based its new recommendations on evidence indicating that treating individuals with HIV earlier, with medicines that are safe, affordable, and easier to manage, can keep them healthy and lower the amount of virus in the blood thereby reducing the risk of passing the virus to others. WHO suggests that doing so, and ensuring that the necessary resources are in place, will result in significant health benefits at the individual and the public health levels. Additional elements of the new recommendations can be found in the complete document cited below.

New Recommendations:

World Health Organization. Consolidated guidelines on the use of antiretroviral drugs for treating and preventing HIV infection. Published 30 June 2013. Available at:

Source: World Health Organization. Media Centre. WHO issues new HIV recommendations calling for earlier treatment. [News release.] 30 June 2013. Available at: Accessed July 2, 2013.