Birth Spacing and Childhood Undernutrition

(March 2009) A large percentage of children in developing countries suffer from undernutrition, characterized as stunting and underweight due to inadequate nutrition intake. Stunting is associated with chronic undernutrition, while underweight reflects both chronic and acute undernutrition. Undernutrition contributes to high rates of child morbidity and mortality, affects long-term childhood growth, and increases susceptibility to diseases later in adulthood. The consequences of undernutrition are relatively irreversible, and the time frame to most effectively address the health problem is limited from pregnancy to 2 years of age. One factor often overlooked when considering strategies to reduce undernutrition is birth spacing, the time interval between births. According to a recent study published in Maternal and Child Nutrition, birth spacing plays an important role in nutritional status among children under 5 years of age, with shorter birth intervals increasing the risk of both stunting and underweight.1

Recent Analysis From El Salvador

In a 2002-2003 reproductive health survey conducted in El Salvador, data on 5,868 children less than 5 years of age were analyzed for the relationships between birth spacing with stunting and underweight. The analysis also took into consideration other variables such as household resources and structure, reproductive history and outcomes, and the social environment of the household. Stunting and underweight are still public health concerns in El Salvador despite the decrease in undernutrition over the past three decades, with stunting rates decreasing from 23 percent to 19 percent between 1988 and 2002, and underweight decreasing 11 percent to 10 percent in the same period.

Analysis from the survey shows that short birth intervals significantly increase the risk of stunting. A child born after an interval of less than 24 months is 1.52 times more likely to be stunted, compared with an interval of 36 to 59 months. Similarly, a child born after an interval of 24 to 35 months is 1.30 times more likely to be stunted than a child born after an interval of 36 to 59 months. As the birth interval length increases, the risk of stunting decreases. The analysis also shows a strong association between short birth intervals and underweight, with decrease association after an interval 36 months or longer.

Birth Spacing and the Effects on Childhood Nutrition

Birth spacing might influence childhood undernutrition through its association with preterm births and low birth weight. If a pregnancy occurs too soon after the previous birth, the mother may not have recovered her nutritional status, which can contribute to preterm birth and low birth weight. Birth spacing allows women to recover and be healthy for their next pregnancy.

Birth spacing effects on childhood undernutrition extend beyond pregnancy and into infancy. Undernutrition increases with age due to premature weaning of breastfeeding and inadequate alternative feeding practices, often as a result of a younger sibling’s birth in a short period of time. In addition to providing high quality nutrition, breast milk strengthens the immune system against infections and diarrheal diseases, two common contributors to weight loss in children. Mothers who adequately space their pregnancies are able to provide their children with the necessary nutrition for growth development and a strong immune system, thereby reducing the likelihood of childhood undernutrition.

Childhood undernutrition is caused by several factors, but birth spacing is often overlooked even though it is strongly associated with stunting, a characteristic of undernutrition. Encouraging women to space births through family planning services and educational awareness could contribute to reducing childhood undernutrition, improve maternal health, and provide healthy childhood development.

Calvin Siow is an intern with International Programs at the Population Reference Bureau.


  1. James N. Gribble, Nancy Murray, and Elaine P. Menotti, “Reconsidering Childhood Undernutrition: Can Birth Spacing Make a Difference? An Analysis of the 2002-2003 El Salvador National Family Health Survey,” Maternal and Child Nutrition 5, no. 1 (2008).