Independent variables | R^{2} | F statistic | p Values | Constant | b1 | b2 | b3 |

TRUST titre | 0.95 | 23.04 | 0.006 | −2.65 | 1.42 | −0.02 | 0.00^{*} |

Gestational month at treatment | 0.98 | 78.16 | <0.001 | −3.13 | 4.83 | −1.41 | 0.12 |

Gestational week×log (1/T)^{†} | 0.99 | 64.32 | 0.003 | −5.61 | 1.20 | −0.05 | 0.00^{*} |

Log (1/T), the log of the reciprocal the TRUST titre in the mother; R

^{2}, coefficient of determination of the model; b1 is the coefficient estimate for independent variable x, b2 for x^{2}, and b3 for x^{3}.↵* The value is less than 0.001.

↵† The interaction between gestational week at treatment for maternal syphilis and log (1/T).

TRUST, toluidine red unheated serum test.