Little Babies May Mean Little Siblings

Small for gestational age babies more likely in second pregnancy if first child was small

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) A small percentage of babies are born very small for their age in pregnancy weeks. It may help doctors prepare for a birth if they know a woman is likely to have a very small baby.

A recent study looked at whether the risk for very small babies was greater in women whose first child was very small.

The results showed that women who had an underweight baby in their first pregnancy were more than six times more likely to have an underweight baby in their second pregnancy.

Knowing ahead of time that a woman has a higher risk of having a very small baby may help the doctor and hospital be prepared for a child with a higher risk of complications.

"Attend all prenatal appointments."

The study, led by Bart Jan Voskamp, MD, of the Department of Obstetrics and Gynecology at the University of Amsterdam in the Netherlands, aimed to better understand the risks for pregnant women who previously had babies who were small for their gestational age.

The term "small-for-gestational-age" (SGA) means that babies were born in the lower fifth of birth weights for the pregnancy week in which they were born.

Infants who are SGA could have experienced fetal growth restriction in the womb, where they did not grow to their full potential. Or they could have been born physically smaller than usual.

Being born SGA is different from being born premature or being born at a low birth weight. It has more to do with being small.

Infants born SGA are at higher risk for death during birth, as well as for other birth complications. Babies born SGA also at a higher risk of poorer health later on in life.

The researchers followed 259,481 pregnant women who gave birth twice to single babies during 1999 to 2007. Of these, 12,943 of the women, or 5 percent, had babies who were SGA in their first pregnancy.

Among women who had SGA babies the first time, 23 percent (2,996 women) had SGA babies during their second pregnancy. Among the women who did not have a SGA baby the first time, however, only 3.4 percent gave birth to a SGA infant during their second pregnancy.

Therefore, women who had one child that was small-for-gestational age were over six times more likely to have another SGA child than if their first child had been in the average growth range.

The study was published in the American Journal of Obstetrics and Gynecology on February 15. Information on funding was not provided. the authors declared no conflicts of interest.

Reviewed by: 
Review Date: 
February 28, 2013
Last Updated:
August 15, 2013