Norethindrone
MedicationProgestin-only contraceptive
Research strength: 3 / 5
MotherToBaby reports that progestin use does not raise miscarriage risk and that an increase in overall birth-defect risk is unlikely. A 2013 case-control study found an association between hypospadias and a broad group of progestin-only pills, but it did not report a norethindrone-only result. A 2005 case-control study found no increased hypospadias risk when progestins were used for contraception; the studies grouped exposure differently. DailyMed states: "Progestin-only oral contraceptives (POPs) should not be used by women who currently have the following conditions: Known or suspected pregnancy." The label also reports no fetal-development effects in many studies of long-term contraceptive-dose oral progestins, but the sources do not give a norethindrone-specific first-trimester estimate. Ask your provider about your situation.
Last reviewed: 2026-10-16
Research strength: 2 / 5
MotherToBaby reports that progesterone or progestin use does not increase miscarriage risk and that an increase in overall birth-defect risk is unlikely, but these are class-wide findings. The 2005 case-control study found no increased hypospadias risk for progestins used for contraception, but it did not provide a separate second-trimester result. DailyMed states: "Progestin-only oral contraceptives (POPs) should not be used by women who currently have the following conditions: Known or suspected pregnancy." The product label reports no fetal-development effects in many studies of long-term contraceptive-dose oral progestins, without results separated by trimester. Ask your provider about your situation.
Last reviewed: 2026-10-16
Research strength: 2 / 5
MotherToBaby says most research on progestins in later pregnancy studied injections or vaginal products used to prevent preterm labor, not contraceptive norethindrone pills. Those studies did not show an increased chance of preterm birth or low birth weight, but they do not establish a result for a norethindrone pill. DailyMed states: "Progestin-only oral contraceptives (POPs) should not be used by women who currently have the following conditions: Known or suspected pregnancy." The label reports no fetal-development effects in many studies of long-term contraceptive-dose oral progestins, but it does not separate results by trimester. Ask your provider about your situation.
Last reviewed: 2026-10-16
Norethindrone — Breastfeeding
Research strength: 4 / 5
CDC's 2024 U.S. MEC rates contraceptive-dose progestin-only pills containing norethindrone category 2 before 30 days postpartum and category 1 from 30 days onward; category 2 means benefits generally outweigh possible risks, and category 1 means no restriction. CDC's 2024 U.S. SPR says these pills may start immediately postpartum if pregnancy can reasonably be ruled out, while DailyMed gives start times of 6 weeks for fully breastfeeding users and by 3 weeks for partially breastfeeding users. LactMed covers oral norethindrone alone for contraception, not high-dose norethindrone acetate or other treatment uses. LactMed reports mixed milk findings, and a 1977 study found lower milk fat and calcium in a low-dose progestogen group, but not a norethindrone-only result. DailyMed notes isolated reports of reduced milk production and very rare infant jaundice, while MotherToBaby says progestins enter milk in low amounts and infant harm is not expected. Ask your provider about your situation.
Last reviewed: 2026-10-16
Sources
- CDC: U.S. Medical Eligibility Criteria 2024, Appendix CUS government
- CDC: U.S. Selected Practice Recommendations 2024US government
- DailyMed: Norethindrone tablet labelDrug company label
- LactMed: NorethindroneUS government
- MotherToBaby: Progesterone and ProgestinsTeratology service
- Toddywalla et al. 1977: Effect of contraceptive steroids on human lactationUS government
Pregnancy
Evidence mostly concerns progestins as a group rather than norethindrone alone. MotherToBaby reports no increase in miscarriage chance and considers an increase in overall birth-defect risk unlikely. Lind et al. 2013 analyzed the National Birth Defects Prevention Study (NBDPS), a population-based case-control study with 1,537 isolated second- or third-degree hypospadias cases and 4,314 controls. Progestin-only oral contraceptive use was associated with hypospadias (adjusted odds ratio 1.9, 95% CI 1.1-3.2), based on 29 exposed cases and 95 exposed controls. The sensitivity analysis excluding low-birthweight infants and multiple births was closer to no association (aOR 1.3, 95% CI 0.7-2.6). The authors described the result as new and called for confirmation; the analysis was exploratory, examined many medication components, and lacked a norethindrone-specific result. Carmichael et al. 2005 studied 502 cases and 1,286 controls. Pregnancy-related progestin use was associated with hypospadias (OR 3.7, 95% CI 2.3-6.0), while progestin use for contraception was not associated with increased risk. The 2005 and 2013 NBDPS analyses have overlapping calendar years and should not be treated as independent replications. DailyMed reports that many studies found no fetal-development effects with long-term contraceptive-dose oral progestins, but provides no trimester-specific or norethindrone-specific estimate.
Breastfeeding
LactMed's record covers oral norethindrone used alone for contraception and states that it has no information on high-dose norethindrone acetate during breastfeeding. LactMed reports mixed milk findings, including a short study with no differences in milk production or composition and a small study reporting lower quantity and quality. Toddywalla et al. 1977 studied 36 postpartum volunteers using different contraceptive methods; its abstract reports lower milk fat and calcium in a low-dose progestogen group, but does not identify a norethindrone-only result or give that group's size. DailyMed reports isolated post-market cases of decreased milk production and very rare infant jaundice. CDC's 2024 U.S. MEC includes norethindrone-containing POPs and rates use category 2 while breastfeeding before 30 days postpartum and category 1 from 30 days onward. CDC's 2024 U.S. SPR says POPs may be started immediately postpartum if pregnancy can reasonably be ruled out. MotherToBaby's class-wide summary says progestins enter breast milk in low amounts and infant harm is not expected.
This entry covers oral norethindrone used alone as a progestin-only contraceptive. LactMed's norethindrone record does not cover combined oral contraceptives or high-dose norethindrone acetate used for treatment. CDC's U.S. MEC categories apply to contraceptive-dose POP use, not every treatment use of a progestin.
What was tested
The product label summarizes long-term contraceptive-dose oral progestin use and gives product instructions. MotherToBaby summarizes several progestins and routes rather than norethindrone alone. The pregnancy studies report maternal medication use and distinguish broad progestin-only pill exposure or indication; they do not provide a norethindrone-specific estimate. CDC's U.S. MEC and U.S. SPR concern contraceptive-dose POPs, including pills containing norethindrone.
Hypospadias and progestin indication
- Source A says
- Lind et al. 2013 reported an association for progestin-only oral contraceptive exposure (aOR 1.9, 95% CI 1.1-3.2), based on 29 exposed cases and 95 exposed controls; the estimate was closer to no association in a sensitivity analysis. (Lind et al. 2013: Maternal medication and herbal use and risk for hypospadias)
- Source B says
- Carmichael et al. 2005 found no increased risk when progestins were used for contraception, while pregnancy-related progestin use was associated with increased risk. MotherToBaby says concerns in some hypospadias studies may reflect study limitations. (Carmichael et al. 2005: Maternal progestin intake and risk of hypospadias, MotherToBaby: Progesterone and Progestins)
- Why they differ
- Carmichael separated contraception from pregnancy-related use; Lind analyzed a broad progestin-only pill group. Neither study reported a norethindrone-only result. The studies use overlapping NBDPS calendar years, so they are not independent replications.
- What the evidence shows overall
- The association merits mention, but the studies do not establish a norethindrone-specific effect. The limited exposed count, exploratory analysis, and sensitivity estimate closer to 1 support reporting the disagreement without presenting a causal conclusion.
Postpartum timing and milk or infant findings
- Source A says
- CDC rates contraceptive POP use category 2 before 30 days postpartum and category 1 from 30 days onward, and its U.S. SPR allows immediate postpartum initiation when pregnancy can reasonably be ruled out. LactMed cites expert opinion that POP use is usually acceptable at any postpartum time. (CDC: U.S. Medical Eligibility Criteria 2024, Appendix C, CDC: U.S. Selected Practice Recommendations 2024, LactMed: Norethindrone)
- Source B says
- DailyMed gives start directions of 6 weeks for fully breastfeeding users and by 3 weeks for partially breastfeeding users, and it reports isolated decreased-milk-production cases and very rare infant jaundice. (DailyMed: Norethindrone tablet label)
- Why they differ
- CDC gives population-level medical eligibility and initiation guidance. DailyMed gives product instructions and post-market reports. These sources address different questions, and the label does not provide a causal estimate or frequency for the reported events.
- What the evidence shows overall
- CDC's categories support contraceptive-dose POP use, with category 2 in the first 30 postpartum days. The label's timing and reports remain visible, but they do not establish a causal infant effect for contraceptive-dose norethindrone or evidence for high-dose norethindrone acetate.
- MotherToBaby says to discuss the specific progesterone or progestin with a health care provider before starting or stopping a progestin-containing medication. (MotherToBaby: Progesterone and Progestins)
- DailyMed says breastfeeding users who suspect that milk production is too low can contact a doctor or clinic. (DailyMed: Norethindrone tablet label)
General research, not specific to pregnancy.
EMA's September 2026 PRAC signal review lists norethisterone among progestogens considered in a class-level meningioma signal and states that no action was taken at that stage. This is not a norethindrone-specific product-label change.
- The EMA signal document lists the signal as "Progestogens - Meningioma (20300)", includes norethisterone in the substance list, and records "No action at this stage". (EMA PRAC recommendations on signals adopted at the 31 August-3 September 2026 meeting)
- MotherToBaby: Progesterone and ProgestinsTeratology serviceSecondary
- DailyMed: Norethindrone tablet labelDrug company labelTertiary
- LactMed: NorethindroneUS governmentSecondaryPage dated 2025-12-15
- CDC: U.S. Medical Eligibility Criteria 2024, Appendix CUS governmentSecondaryIndependent check
- CDC: U.S. Selected Practice Recommendations 2024US governmentSecondaryPage dated 2024-08-08Independent check
- Lind et al. 2013: Maternal medication and herbal use and risk for hypospadiasUS governmentPrimaryIndependent check
- Carmichael et al. 2005: Maternal progestin intake and risk of hypospadiasUS governmentPrimaryIndependent check
- Toddywalla et al. 1977: Effect of contraceptive steroids on human lactationUS governmentPrimaryIndependent check
- EMA PRAC recommendations on signals adopted at the 31 August-3 September 2026 meetingEU agencySecondaryPage dated 2026-09-28European guidance
Last reviewed 2026-10-16
Independent check 2026-10-16
Not yet clinician-reviewed
Ask your provider about your situation.
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