Does Postpartum Contraceptive Use Vary By Birth Intendedness?

Women with an unintended birth have an elevated risk of subsequent unintended pregnancy, and multiple unintended pregnancies could exacerbate any negative consequences of such births. It is therefore important to understand whether postpartum contraceptive use differs by birth intendedness.

Data on 2,769 births reported in the 2011-2015 cycles of the National Survey of Family Growth were used to examine postpartum contraceptive use. Life-table estimates were employed to assess differences by birth intendedness in timing of postpartum contraceptive use, and multinomial logistic event history methods were used to model initial contraceptive uptake and efficacy by birth intendedness.

Compared with postpartum women whose births were on time or too late, those with seriously mistimed and those with unwanted births were more likely to first adopt a highly effective method (e.g., implant or IUD), rather than no method (relative risk ratios, 1.9 and 1.7, respectively); mothers with unwanted births were also more likely to first use least effective methods (e.g., condoms or withdrawal) instead of no method (1.5). Mothers with seriously mistimed births had a reduced likelihood of using either effective methods (e.g., the pill or injectable) or least effective methods, rather than highly effective ones (0.5 for each).

The elevated risk of repeat unintended fertility does not seem to be due to mothers' initial postpartum contraceptive behavior. Whether mothers with unintended births use contraceptives less consistently, discontinue use sooner or switch methods more often than those with intended births remains to be seen.