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.
No, it's not true! You can get pregnant before you have your first period, and many unplanned pregnancies happen just that way. To prevent pregnancy after you have your baby, you have to use birth control every time â even if you're breastfeeding. You're fertile around the time you ovulate, and you ovulate before you get your period, which can be anywhere from seven to 19 days before if you have a 28-day cycle, for example. You can get your period again from a month to over a year after having a baby.