Analysis of the outcome of 124 pregnancies produced during NFP.

The outcome of 124 pregnancies produced during the use of CM (Billings) of NFP is analyzed. The spontaneous abortion rate was 8%. The women who became pregnant in the less fertile period (+/- 3 days from peak day) presented a higher rate of spontaneous abortions (13.9%) than the women who became pregnant during the most fertile period (peak day +/- 2 days), who presented a 4.3% spontaneous abortion rate. Among the 115 living infants (one twin pregnancy) there was one congenital malformation (0.8%), a cleft palate. The sex ratio of the infants was 0.59 (48 females and 67 males), which is not significantly different from the 0.51 sex ratio expected. When conception occurred during the most fertile period, the sex ratio was 0.37, in contrast to the sex ratio of 0.76 when conception occurred in the less fertile period; this is a highly significant difference (P less than 01).