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.
If you bottle feed your baby, or combine bottle feeding with breastfeeding, your first period could start as soon as five to six weeks after you give birth.If you fully breastfeed and do not combine bottle feeding with breastfeeding, it is possible that your periods may not start again until you stop breastfeeding.f your period does return while you are breastfeeding, it may be irregular. It is not unusual for a woman's menstrual cycle to go quicker or slower than normal while she is breastfeeding. Sometimes a woman who is breastfeeding will skip periods altogether, or have months in between periods.