Increases in the average interbirth interval for recipient mares did not seem to be driving this result, as foaling date was not affected by the number of years (cumulative or consecutive) that mares failed to conceive.
However, given the slow life history traits of chimpanzees, whose average interbirth interval is more than 5 years [ 95], this is unlikely since relatively few deaths, births, or migrations into or outside of the corridor area would be expected to occur during this time.
Study design: This retrospective study looked at twin births in two maternity units in the Paris, France metropolitan region: Antoine Béclère (AB) in Clamart, and Port-Royal (PR) in Paris and concerned 113 deliveries of pairs of twins at AB and 78 at PR. Results: The mean duration of the interbirth interval was 9 min at AB and 5 min at PR (P<0.001).
A total of 1268 mothers with IPI (interbirth interval minus 9 months' gestation) had CVD risk factors measured/imputed at mean age 48 years.
Interestingly, prior to the application of PZP, the average month of birth did tend to increase with interbirth interval (Linear Mixed Effects Model: estimate = 0.30, SE = 0.17, t = 1.82, r2 = 0.06, P = 0.07) [22], demonstrating at least some plasticity in the scheduling of reproductive cycling in Shackleford mares.
Conclusion: The neonatal results were similar in both groups, even though both the rate of obstetric maneuvers and the interbirth interval differed significantly.
The increased fecundity was actualized by decreased interbirth interval and a longer reproductive period (greater age at last birth); the proximate (molecular) mechanisms relating altered function of BRCA1/2 to increased fecundity remain unclear.
The purpose of this study was to establish estimates for recurrence risk of preeclampsia based on gestational age at delivery of the first pregnancy complicated by preeclampsia and to determine whether interbirth interval, paternity, and body mass index (BMI) modify that risk in women with prior preeclampsia.
The gestation period lasts 158 days with a 16-22 month interbirth interval.
