"...heavenly father knows YOU need..." Mathew 6:32 "...assist her in any matter where she may need YOU..." Romans 16:2 "..according to the due right of daughters.." Exodus 21:9
In the machine age a few may either become detached from, insensitive to or hasty about needs and wants in oneself and/or of the partner. Perhaps woman, more than men, may desire being needed by men. And men, more than women, may desire being wanted by women. Both wants and needs may reflect desiring acceptance.
The intensity of "wanting" may differ from "needing". "Wanting" reflects seeking an object of desire from outside; this seems somewhat detached from the inner need. "Needing", on the other hand, reflects the inner desire as that interacts with the conduct of seeking a fulfilling object. Basic as these may seem, there may be a difference in intensity between wanting and needing.
Even though there seems to be a 'God Given Right' attributed to "needing", that is not the same for "wanting". People seem to give more empathy or sympathy (and perhaps legal right) to the needs others. And that does not hold the same stricture for "wanting". Wanting does not preclude having the right to have something. Needing seems to preclude having the right to something.
Given the above one could erroneously conclude that men and women have unequal rights when needs and wants are concerned. The scenario seems to reverse during pregnancy. A child bearing women may "need" the emotional, physical and financial support of the man. While childbearing, the woman may want to hear that she is "wanted"; and men may want to hear that they are "needed". That is not being needed by the man. The legal rights change too. While she has the "need" and the "right", she wants to be "wanted". And while he wants to be "wanted" and has little right, he wants to be "needed". These may pose a disjunction in the relation causing distress during pregnancy.
One source of marital conflict may be the disjunction between rights and wants and rights and needs; that is basically the conflict between the inner and the outer self, which is not entirely about the marital couple; the conflict is between the "self" and the "outside" world. This knowledge may help the couple understand the difference between one's own and the partner's needs and wants about being "needed" or "wanted" at different times.