Optimal Timing for Subsequent Pregnancy
For healthy women under 35 years old, you can attempt pregnancy as soon as you feel ready after a previous pregnancy, though waiting at least 6 months after miscarriage or 12-18 months after childbirth may reduce risks of adverse outcomes, particularly in older women or those with complications. 1
General Population Recommendations
After Uncomplicated Childbirth
- The World Health Organization has traditionally recommended interpregnancy intervals of 1-2 years after childbirth to reduce adverse pregnancy outcomes 1
- Recent evidence suggests these strict intervals may not be necessary for healthy women under 35 years old 1
- Fertility returns within 1 month after pregnancy ends unless breastfeeding occurs 1
After Miscarriage
- Traditional WHO guidance recommends waiting at least 6 months after miscarriage before attempting conception 1
- However, subfertile couples who miscarry have excellent prospects: 70% achieve spontaneous ongoing pregnancy within 24 months, with 91% of subsequent pregnancies being ongoing 2
- Women with unexplained recurrent miscarriage show median time to conception of 21 weeks, with 74% conceiving within 12 months 3
Special Populations
After Breast Cancer
For breast cancer survivors, it is reasonable to postpone pregnancy for 2 years following diagnosis to allow adequate ovarian function recovery and to pass the timeframe of highest recurrence risk 4
Key considerations for breast cancer survivors:
- Pregnancy after breast cancer is safe and not detrimental to maternal prognosis, regardless of estrogen receptor status 4
- The 2-year waiting period accounts for both ovarian function recovery and peak recurrence risk 4
- For patients on adjuvant tamoxifen (typically 5 years), interruption after 2-3 years may be considered if completing the full course would eliminate pregnancy chances, though this carries potential risks to breast cancer outcomes 4
- Tamoxifen should be resumed after delivery 4
After Other Cancers
- For cancer survivors other than breast cancer, no specific waiting period is mandated 4
- Timing should consider completion of therapy, risk of relapse, patient age, and ovarian function 4
- Neonatal outcomes in cancer survivors are comparable to the general population 4
After Endometriosis-Related Infertility
- Women with endometriosis who successfully deliver have uniformly good prospects for conceiving subsequent children, regardless of disease stage, treatment method, duration of initial infertility, or patient age 5
Contraception Timing Considerations
If Avoiding Immediate Pregnancy
Without breastfeeding, effective contraception should be started as soon as possible if another pregnancy is to be avoided 1
- Ovulation can resume as early as 21 days postpartum in non-breastfeeding women 6
- Long-acting reversible contraceptives (IUDs and implants) can be safely inserted immediately postpartum before hospital discharge 7, 6
- Combined hormonal contraceptives should be delayed until 6 weeks postpartum due to increased venous thromboembolism risk 1
Breastfeeding Considerations
- Breastfeeding suppresses fertility but is not reliable contraception 1
- Fertility awareness methods are not recommended before 6 weeks postpartum for breastfeeding women 7
- Progestin-only methods are safe during breastfeeding 7
Common Pitfalls to Avoid
- Do not assume fertility has ended before confirmed menopause (12 months without menses), as unintended pregnancy remains possible 8
- Do not delay contraception counseling until the 6-week postpartum visit if pregnancy avoidance is desired—discuss during pregnancy and offer methods before hospital discharge 6
- Do not recommend abortion for breast cancer patients who become pregnant, as it has no impact on maternal prognosis 4