A comparison made with a control group of mothers of normal, term infants showed that for the former the follicular phase during the conceptional cycle was longer than for the latter (20.4 and 16.9 days, respectively). Moreover, the mothers of malformed infants showed a slower temperature rise (greater than 3 days) in 45% of cases, vs 28% in the controls. The menarche of the mothers of malformed infants occurs later (14.3 vs 12.8 years). They usually have long menstrual cycles and a bad obstetric and gynecological history.
http://linkinghub.elsevier.com/retrieve/pii/0378378285900842
An analysis has been made of the general reproductive characteristics of mothers. The differences observed have shown that the mothers of malformed infants had their first menstrual period at a later age (13.4 vs 12.8 years), their menstrual cycles were more often irregular (77% vs 40%) and lasted longer (32.9 vs 30.1 days). Moreover, they had a longer follicular phase during both their preconception cycle (21.7 vs 17.6 days) and during their conception cycle (24.0 vs 18.1 days), as well as a longer temperature rise during their conception cycle (3.7 vs 3.0 days). By taking into account the relation between these variables, we have been able to show that increased risk of malformation is associated with increase in the length of the follicular phase and the temperature rise of the conception cycle.
http://linkinghub.elsevier.com/retrieve/pii/0378378285900854
The results of in vitro fertilization and pre-implantation diagnoses confirm the suspicion that some women are more prone to trisomies or polyploidy.
http://www.ncbi.nlm.nih.gov/pubmed/21077516
Menstrual Cycle and Miscarriage
Normalizing the Menstrual Cycle
Menstrual Cycle and Birth Defects
For a concise list of qualities found to affect one's risk of miscarriage, see: Causes of Miscarriage