The genotype of the mother and the fetus influences the efficacy of a teratogen. For example, genotype determines the prevalence of cleft palate in inbred strains of mice whose mothers are administered cortisol during pregnancy.
Most women will not start ovulating in the first six weeks after giving birth.1 Breastfeeding typically delays the onset of ovulation.2 Depending on the intensity of breastfeeding, it can be several months or over a year before you regain your fertility.
The hormones circulating while you're breastfeeding can temporarily suspend ovulation, so you may not see a period (or experience a regular one) until you wean your baby. Your period should return within six to eight weeks after you stop breastfeeding, though it can take months for it to be totally regular again.If you think you should be menstruating and you're not, give your doctor a call.: How soon will I get my period back after having my baby? A: If you're not breastfeeding, it usually takes about six to eight weeks for your period to return to normal after delivery.