Pregnancy · Neonatal Outcomes

Intelligence and prenatal progesterone

Meyer-Bahlburg HF

Published November 1979 Journal of the Royal Society of Medicine, 72(11), 878
DOI 10.1177/014107687907201119 PMID 552453 PMC PMC1437139
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RRM Academy Synopsis

No evidence prenatal progesterone raises children's IQ

One doctor had claimed that progesterone given during pregnancy raises a child's later IQ. This letter argues the claim is not backed up. The author rechecked the data and found no evidence to support the claim for children's intelligence.

Key Findings

  • A reanalysis of the original data found that most reported IQ differences were not statistically significant after all.
  • A study with a sibling control group found no significant IQ difference between the two groups, though both scored somewhat above the general population.
  • The author's own team compared 28 boys and girls, ages 8 to 14 years, who had prenatal exposure to a progesterone drug, against matched controls. They found no significant difference in intelligence.
  • Some of the other studies used to support the claim had no control group at all, so their results could not rule out other causes.
  • In 1979 the author wrote that double-blind trials of progesterone and other progestogens had failed to show lower rates of miscarriage, early birth, or low birth weight in high-risk pregnancies.

Interpretation

The document is a letter to a medical journal. It presents no new study. The letter is one psychologist's critical review of data used to support an earlier claim. A letter like this carries less weight than a full peer-reviewed study, but it can still expose real statistical problems. The studies reviewed here were small. Some had no control group. Several of the cited studies enrolled patients with adrenogenital syndrome, a rare hormone condition, or girls exposed to progestins. None of these designs can prove that progesterone changes a child's intelligence. At most, they show the original claim rested on weak evidence.

RRM Context

The 1979 letter is old and not about restorative reproductive medicine. NaProTechnology protocols use cycle-timed progesterone to correct a measured hormone shortfall. It does not aim to raise a child's IQ. The letter is a reminder: a hopeful claim about hormones and children needs a careful recheck before anyone trusts it.

Abstract not indexed.

Topics

Related research

Pregnancy › Neonatal Outcomes › Neonatal Morbidity · Therapeutics › Hormonal Agents › Progesterone and Progestins · Reproductive Endocrinology › Neuroendocrinology › Hypothalamic Pituitary Axis
PMID 552453 552453 DOI 10.1177/014107687907201119 10.1177/014107687907201119 Meyer-Bahlburg et al. 1979, Meyer-Bahlburg 1979

Cite this article

Meyer-Bahlburg, H. F. L. (1979). Intelligence and prenatal progesterone. Journal of the Royal Society of Medicine, 72(11), 878. https://doi.org/10.1177/014107687907201119