Closely spaced pregnancies: a risk for autism?

Closely Spaced Pregnancies = Autism?A study published today in the journal, Pediatrics, examines the interval between pregnancies and the odds of a child having autism. Researchers looked at the birth records of 660,000 second-born children born in California and the timing of their conception after the oldest sibling was born.

The results? Compared to children who were conceived at least three years after their sibling was born:

  • Babies conceived less than 12 months after the birth of the first-born child were THREE times more likely to be diagnosed with autism spectrum disorder (ASD).
  • Babies conceived from 12 to 23 months after the birth of the first-born child had almost two times the risk of ASD.
  • And, even babies conceived 23-35 months after the first-born child had a slightly greater risk of ASD.

Unfortunately, the researchers have no idea why the odds are greater when the spacing between pregnancies is shorter. Perhaps it’s because a woman’s nutritional stores have not had enough time to be replenished. Or maybe women who have put off parenthood until later in life have more closely spaced babies—and parental age itself is a risk factor for having a child with an ASD. This study isn’t going to give us those answers.

Bottom line: We are learning more and more about autism every day. Thus study alone should not necessarily influence your decision on how long to wait between pregnancies. However, the current recommendation from the Centers for Disease Control is to wait at least 18-23 months between pregnancies for a mother and baby’s optimal health.