What oral contraceptives (birth control pills) are safe for a breastfeeding mother to use?

Oral Contraceptives During Breastfeeding

Progestin-only pills (POPs) are the safest oral contraceptive option for breastfeeding mothers and can be started immediately postpartum, while combined hormonal contraceptives (containing estrogen) should be avoided during the first 6 weeks and generally not used until after 6 months of breastfeeding due to risks of reduced milk production and venous thromboembolism. 1

Progestin-Only Pills (POPs) - First-Line Choice

Progestin-only pills are the recommended oral contraceptive for breastfeeding women. 1, 2

Safety Profile

• No adverse effects on milk volume or composition 3, 4
• No detrimental effects on infant growth or development 3, 5
• Minimal steroid transfer into breast milk - amounts are very low and insufficient to affect the infant 3
• Can be initiated at any time postpartum, including immediately after delivery 4

Optimal Timing

• While POPs can be started immediately, ideally begin at 6 weeks postpartum if fully breastfeeding to minimize infant hormone exposure and reduce irregular bleeding 4
• No backup contraception needed if started within 6 months postpartum while amenorrheic and fully/nearly fully breastfeeding (≥85% of feeds are breastfeeds) 1
• If started >21 days postpartum without return of menses, use backup contraception for 7 days 1

Efficacy

• Perfect use failure rate: 0.5% 2
• Typical use failure rate: approximately 5% due to missed or late pills 2

Combined Hormonal Contraceptives (CHCs) - Avoid During Breastfeeding

Combined oral contraceptives containing estrogen should not be used during breastfeeding, particularly in the first 6 months postpartum. 1

Contraindications and Timing Restrictions

• Absolute contraindication (U.S. MEC Category 4): First 3 weeks postpartum due to increased venous thromboembolism risk 1
• Generally should not use (U.S. MEC Category 3): 4 weeks to 6 months postpartum due to potential negative effects on breastfeeding performance 1
• Additional VTE risk factors make CHCs inadvisable at 4-6 weeks postpartum 1

Effects on Lactation

• 60-80% of breastfeeding women experience increased frequency and severity of symptoms when using estrogen-containing contraceptives (in context of hereditary angioedema, but mechanism applies broadly) 1
• Estrogen decreases milk volume 5
• May lead to earlier discontinuation of breastfeeding 4

When CHCs Might Be Considered

• After 6 months postpartum when breastfeeding is well-established and supplementation is available 6
• For women planning gradual weaning, as decreased milk volume may facilitate transition to bottle-feeding 4
• Only if woman has reliable access to supplemental milk 4

Clinical Algorithm for Breastfeeding Women

1. First-line: Progestin-only pills

   • Start at 6 weeks postpartum (optimal) or immediately if contraception urgently needed 4
   • No backup needed if <6 months, amenorrheic, and fully breastfeeding 1

2. Avoid combined hormonal contraceptives

   • Absolutely contraindicated <3 weeks 1
   • Generally avoid until >6 months postpartum 1

3. If woman insists on CHCs

   • Wait minimum 6 weeks postpartum 1
   • Ensure no additional VTE risk factors 1
   • Confirm access to supplemental milk 4
   • Counsel about potential milk volume reduction 5

Common Pitfalls to Avoid

• Do not prescribe combined oral contraceptives in the first 6 weeks postpartum - this carries unacceptable VTE risk (Category 4) 1
• Do not assume all oral contraceptives are the same - the distinction between progestin-only and combined formulations is critical for breastfeeding women 1
• Do not delay contraception unnecessarily - progestin-only pills can be safely started immediately postpartum if needed 4
• Do not prescribe CHCs to women without reliable access to supplemental milk - decreased milk volume can lead to contraceptive discontinuation and unintended pregnancy 4