Nora was right when she said that some couples are not as able to have children as others, even though they may want them. One thing that can help you learn more about your couple is to do a doctor's consultation, which can tell you if Baby Boost (a euphemism for medical assistance/fertility treatments) is needed for either the husband or wife. To be completely sure, though, you'll need to check both parents, since either (or both) of them may need Baby Boost. More than one shot for each parent improves chances, although it's expensive to do that. That's why I usually spend the 99 cents for Health Plan, since it really keeps those frequent illnesses from eating up my family's savings and lets me spend their coins on more satisfying things than medicine. For my long-running families that have saved up a lot of money, I'll often give each parent several Baby Boost shots to save time.