In Nigeria, as in many other African countries, men have stronger ownership rights over land than women do. This gives everyone an economic need for sons, including women, who face a grim widowhood without one. The need for sons changes fertility patterns. According to the latest  demographic and health survey (financed by the American government) [USAID], women whose first child is a daughter are likely to have more children than those whose first child is a son. They are less likely to use contraceptives. And, if their first three children are daughters, they are very likely to have a fourth very quickly (within 15 months). The differences are small but consistent: having a daughter first changes child-bearing choices later.
It also changes a woman’s married life. Women with first-born daughters are 1.2 percentage points more likely to end up in a polygamous union. Some husbands, it turns out, take another wife if their first child is a girl (polygamy is legal in northern Nigeria and recognised by customary law elsewhere). Men also seem more willing to abandon or divorce wives who produce a daughter. Among women aged 30 to 49, those with first-born girls are more likely to be divorced, have a non-resident husband or be the head of a household.Before you get too discouraged, however, I should note that things are better in the southern part of Nigeria than in the northern part (the latter being the realm of Boko Haram). I pulled the following table from the StatCompiler feature of the Demographic and Health Survey website. You can see that fertility is considerably higher and the age at marriage considerably younger in the north than in the south. The next question is how to diffuse those southern attitudes northward.