Breastfeeding Birth ControlvsCervical Cap

A side-by-side comparison of two birth control methods — efficacy, cost, how they work, and who shouldn't use them.

Side-by-side comparison

Method	Breastfeeding Birth Control A natural postpartum method (lactational amenorrhea method, LAM) that relies on exclusive breastfeeding to suppress ovulation, effective for up to 6 months.	Cervical Cap A small silicone cap that fits over the cervix by suction, used with spermicide before sex.
Efficacy	98% typical use Moderately effective: over 90 out of 100 people successfully prevent pregnancy per year.	Least effective see details Least effective: under 90 out of 100 people successfully prevent pregnancy per year.
Cost	$0–$300 Insurance: Varies	$73–$97 Insurance: Usually
Duration	Up to 6 months postpartum	Reusable for 2 years (replace every 2 years or sooner if damaged)
Reversibility	Reversible	Reversible
STI Protection	No	No
How it works	Exclusive breastfeeding suppresses the hormones that trigger ovulation. High prolactin from frequent nursing keeps estrogen and progesterone low, preventing the return of menstrual cycles.	A small silicone cap fits snugly over the cervix and stays in place by suction, blocking sperm from entering the uterus. Used with spermicide inside the cap.
Prescription	OTC No prescription / OTC	Required Prescription required
Side effects	None reported	Vaginal irritation from spermicide Discomfort if not fitted correctly Unusual vaginal discharge if left in too long
Who shouldn't use this	Baby over 6 months old Periods have returned Not exclusively or nearly exclusively breastfeeding Use of supplemental formula or solid foods	Cervical anomaly preventing fit Active pelvic infection Sensitivity to silicone or spermicide Inability to insert or remove reliably

Key differences

Breastfeeding Birth Control duration: Up to 6 months postpartum. Cervical Cap duration: Reusable for 2 years (replace every 2 years or sooner if damaged). Cervical Cap requires a prescription; Breastfeeding Birth Control does not. Breastfeeding Birth Control: costs $0–$300. Cervical Cap: costs $73–$97.