Pre-Conception · Endocrine
PCOS & Pregnancy Care
PCOS affects 10% of women. Here's what it means for getting pregnant, staying pregnant, gestational diabetes risk, and postpartum care — based on the 2023 international guideline (Teede et al.).
Last reviewed 1 June 2026
PCOS in pregnancy
Rotterdam diagnosis + pregnancy management
Rotterdam criteria (≥ 2 of 3)
Additional risk factors
Rotterdam not met
PCOS diagnosis requires ≥ 2 of 3 Rotterdam criteria with exclusion of thyroid disease, hyperprolactinaemia, non-classical congenital adrenal hyperplasia. If criteria met later, re-evaluate antenatal risks.
Troubleshooting + common pitfalls
- Pitfall: Diagnosing PCOS on ultrasound alone.
Solution: Polycystic ovarian morphology on US is just one Rotterdam criterion. Need 2 of 3 + exclude thyroid disease, hyperprolactinaemia, NCAH. Adolescents need slightly different criteria (Teede 2023 — first 8 yr post-menarche US is unreliable). - Pitfall: Missing aspirin for PE prophylaxis.
Solution: PCOS is a USPSTF / ACOG / NICE moderate-risk factor for PE. Aspirin 150 mg from < 16 wk if other moderate factors coexist (obesity, primigravida, age ≥ 35) or high-risk factor present. - Pitfall: GDM screening at 24–28 wk only.
Solution: Booking HbA1c + fasting glucose to catch undiagnosed T2DM (PCOS ~2× baseline T2DM risk), then OGTT at 24–28 wk. Earlier OGTT if BMI ≥ 35 or HbA1c borderline. - Pitfall: Continuing metformin lifelong in pregnancy “because it’s PCOS”.
Solution: Routine metformin throughout pregnancy is not evidence-supported in PCOS (INSIGHT 2024 didn’t confirm miscarriage benefit). If conceived on metformin, continue 1st trimester per RCOG; stop at 12 wk unless GDM develops or BMI ≥ 35. - Pitfall: Missing OSA + cardiometabolic comorbidities.
Solution: PCOS + obesity has higher rates of OSA, NAFLD, hypertension, T2DM. Pregnancy is the high-risk vulnerable period — screen and address. - Pitfall: Mental health overlooked.
Solution: PCOS-associated depression / anxiety doubles in prevalence and intensifies in pregnancy. EPDS at booking, 28 wk, postpartum. Eating disorder history common; address sensitively. - Pitfall: LGA / macrosomia underprepared.
Solution: Growth scans 28, 32, 36 wk in BMI ≥ 30 or GDM. EFW > 90th centile prompts review of glycaemic control and discussion of delivery timing (37–39 wk). - Pitfall: Forgetting recurrence + future health.
Solution: PCOS women have ~2× lifetime T2DM, cardiovascular disease, endometrial cancer risk. Postpartum 75 g OGTT at 6–12 wk if GDM developed; annual HbA1c thereafter; cardiovascular risk discussion. - Pitfall: Stigmatising weight discussion.
Solution: PCOS + weight is a sensitive topic. Use neutral motivational interviewing; focus on health outcomes not aesthetics; integrate dietitian / psychology where helpful. - Pitfall: Missing congenital adrenal hyperplasia.
Solution: 17-OH-progesterone at booking if hyperandrogenism prominent — NCAH mimics PCOS and has different management. - Pitfall: No pre-conception counselling.
Solution: PCOS women have higher GDM, PE, miscarriage, PTB. Pre-conception weight optimisation, HbA1c < 6.5 %, BP control, folate 5 mg if BMI ≥ 35 — lower antenatal risk substantially. - Pitfall: Contraception postpartum not discussed.
Solution: See /calculators/postpartum-contraception. LARC works well in PCOS; CHC has the usual VTE caveats; progestin-only methods sometimes worsen androgenic side effects (acne, hair changes) but are otherwise compatible.
Educational tool only — not medical advice. Teede 2023 International PCOS Guideline; Rotterdam 2003; NICE NG3. Management by GP / obstetric / endocrine team.
What does this mean?
PCOS affects ~10–13 % of women of reproductive age and is the commonest endocrine disorder of pregnancy. The Rotterdam criteria (2 of 3 + exclusion of mimics) is the diagnostic gold standard, with the 2023 international evidence-based guideline (Teede et al.) the current authoritative consolidation. Pregnancy-specific risks: miscarriage ~30 % (vs 10–15 % background), GDM ~3× baseline, PE ~2× baseline, preterm birth ~1.5× baseline, plus elevated LGA / macrosomia (particularly if GDM coexists). Practical management: (1) aspirin 150 mg nightly from < 16 wk for PE prophylaxis (PCOS is a USPSTF / ACOG / NICE moderate-risk factor); (2) booking HbA1c + fasting glucose to catch undiagnosed T2DM, then OGTT at 24–28 wk; (3) growth scans at 28/32/36 wk if BMI ≥ 30 or GDM develops; (4) mental-health screening at booking, 28 wk, postpartum — PCOS depression/anxiety doubles and pregnancy intensifies it. Two debated points: metformin in pregnancy — INSIGHT 2024 didn’t confirm a miscarriage-reduction benefit; current practice is to continue if conceived-on-metformin through 1st trimester per RCOG, but not routinely start for PCOS alone; polycystic ovarian morphology in adolescents — the first 8 years post-menarche are unreliable on US, so Rotterdam US criterion isn’t applied in that age group. Beyond pregnancy, PCOS doubles lifetime T2DM, cardiovascular and endometrial-cancer risk — postpartum 75 g OGTT and annual HbA1c are not optional.
Can I get pregnant with PCOS?
Yes — most women with PCOS do get pregnant, though it may take longer or need help. PCOS is the most common cause of female infertility but it’s treatable.
About 70-80% of women with PCOS will conceive — many naturally, others with help (weight management, ovulation induction with letrozole or clomiphene, sometimes IVF).
What is PCOS?
PCOS (POLYCYSTIC OVARY SYNDROME) is a hormonal condition affecting ~10% of women of reproductive age. Despite the name, the “cysts” are actually small under-developed follicles that haven’t released eggs.
Key features:
- Irregular periods or no periods.
- Higher levels of androgens (acne, extra body hair, scalp hair thinning).
- Multiple small follicles on ovary ultrasound.
Not every woman with PCOS has all three.
Rotterdam diagnostic criteria
Need at least 2 of 3:
- Irregular or absent periods (oligo / anovulation).
- Clinical or biochemical signs of high androgens.
- Polycystic ovaries on ultrasound (≥12 follicles per ovary OR ovary volume >10 ml).
Must rule out other causes (thyroid issues, hyperprolactinaemia, non-classical congenital adrenal hyperplasia).
2023 update: AMH blood test can replace ultrasound in adults; not useful in first 8 years post-menarche.
Pregnancy risks with PCOS
- Miscarriage ~30% (vs 10-15% background).
- Gestational diabetes ~3x baseline.
- Pre-eclampsia ~2x baseline.
- Preterm birth ~1.5x baseline.
- Large-for-dates / macrosomia (especially if GDM).
- C-section rates slightly higher.
With extra monitoring, most PCOS pregnancies are healthy.
Aspirin for pre-eclampsia?
NICE / RCOG / ACOG / USPSTF: PCOS alone is a MODERATE risk factor. Aspirin 150 mg nightly from before 16 weeks if you have:
- Any high-risk factor (chronic high BP, T1DM/T2DM, kidney disease, autoimmune disease, previous pre-eclampsia).
- PCOS PLUS one or more other moderate factors (BMI ≥35, first baby, age 35+, family history of pre-eclampsia).
Discuss at booking.
Gestational diabetes screening
- Booking (8-12 wk): HbA1c + fasting glucose — catch undiagnosed pre-existing diabetes.
- Early OGTT (16-18 wk) if HbA1c borderline or BMI ≥35.
- Standard 75g OGTT at 24-28 wk for everyone with PCOS.
- If GDM develops: insulin / metformin / diet management.
- Postpartum: 6-12 week OGTT; annual HbA1c thereafter.
Metformin — continue or stop?
- Conceived ON metformin (PCOS fertility treatment): RCOG suggests continue through 1st trimester. Stop at 12 weeks unless GDM develops or BMI ≥35.
- Pre-existing diabetes: continue throughout pregnancy alongside insulin if needed.
- Never taken metformin: don’t routinely start — INSIGHT 2024 trial didn’t confirm benefit.
Different scenarios — PCOS pregnancies
Scenario 1: 28-year-old, just diagnosed PCOS, wanting to conceive
Lifestyle: weight management; folic acid 400 mcg-5 mg from 3 months before trying. Track cycles. If >12 months trying naturally without conception: see GP for fertility referral. Letrozole now first-line for ovulation induction in PCOS (PPCOS-II trial).
Scenario 2: PCOS + BMI 36, trying for second baby
Weight loss 5-10% before pregnancy improves ovulation and outcomes. Folic acid 5 mg. Pre-conception HbA1c. Aspirin in pregnancy. Plan early GDM screening + growth scans.
Scenario 3: PCOS pregnancy, 28 weeks, GDM diagnosed
Dietitian; glucose monitoring 4x/day; metformin or insulin if needed. Growth scans 32, 36 weeks. Plan delivery 37-39 weeks if LGA. Postpartum: OGTT 6-12 weeks.
Scenario 4: PCOS + history of recurrent miscarriage
Workup: thyroid, antiphospholipid, anatomical. Optimise weight, glucose, vitamin D. Progesterone vaginal pessary if 3+ losses + bleeding (PRISM trial subset).
Scenario 5: PCOS, 6 months postpartum, struggling with body image
Normal — postpartum + PCOS often hard. Speak with GP / perinatal mental health. Dietitian referral. Reject weight-stigmatising language. Verity / PCOS UK / Mind charity support.
Care guidance — PCOS in pregnancy
- Preconception folic acid 400 mcg-5 mg from 3 months before.
- Booking: HbA1c, BP, BMI, thyroid, vitamin D, EPDS / GAD-7.
- Aspirin if PE moderate-risk factors apply.
- Early GDM screen 16-18 wk if BMI ≥35 or HbA1c borderline.
- Standard 75g OGTT 24-28 wk.
- Growth scans 28, 32, 36 wk if BMI ≥30 or GDM.
- Mental health screening every trimester + postpartum.
- Lactation support early — PCOS may delay or reduce supply.
- Postpartum OGTT 6-12 weeks if GDM developed.
- Annual HbA1c, lipids, BP, BMI long-term.
- Postpartum contraception — ovulation can return unpredictably.
Sources
- Teede HJ, et al. Recommendations from the 2023 International Evidence-based Guideline for the Assessment and Management of PCOS.
- NICE NG3. Diabetes in pregnancy: management.
- NICE NG126. Ectopic pregnancy and miscarriage.
- RCOG. Long-term consequences of polycystic ovary syndrome (Green-top guideline 33).
- Rotterdam ESHRE/ASRM Consensus. Revised 2003 consensus on diagnostic criteria for PCOS.
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Frequently asked questions
Can I get pregnant with PCOS?
Yes — most women with PCOS do get pregnant, though it may take longer or need help. PCOS is the most common cause of female infertility but it's TREATABLE. About 70-80% of women with PCOS will conceive — many naturally, others with help (weight management, ovulation induction with letrozole or clomiphene, sometimes IVF). The key issue is anovulation (no regular ovulation) — so tracking when (or if) you ovulate matters. SEE GP / fertility clinic if trying for 6-12 months without success. Early help works.
What is PCOS exactly?
PCOS (POLYCYSTIC OVARY SYNDROME) is a HORMONAL condition affecting ~10% of women of reproductive age. Despite the name, the issue isn't the cysts themselves — they're actually small under-developed follicles that haven't released eggs. KEY FEATURES: (1) IRREGULAR PERIODS or no periods; (2) HIGHER LEVELS of male-pattern hormones (androgens) — can cause acne, extra body hair, scalp hair thinning; (3) MULTIPLE small follicles on ovary ultrasound. NOT EVERY WOMAN with PCOS has all three. CAUSES not fully understood — insulin resistance, genetic factors, hormonal imbalance. Lifelong condition but very manageable.
How is PCOS diagnosed?
ROTTERDAM CRITERIA (2003, updated by Teede et al. 2023): need at least 2 of 3: (1) IRREGULAR or absent periods (oligo / anovulation); (2) Clinical or biochemical signs of HIGH ANDROGENS (acne, hirsutism, scalp hair thinning OR raised testosterone on blood test); (3) POLYCYSTIC OVARIES on ultrasound (≥12 follicles per ovary OR ovary volume >10 ml). Must rule out other causes (thyroid issues, hyperprolactinaemia). UPDATE 2023: anti-Müllerian hormone (AMH) blood test can replace ultrasound in adults. NOT useful in first 8 years after periods start.
What are the risks of PCOS in pregnancy?
PCOS increases several pregnancy risks but most pregnancies go well with extra monitoring. RISKS: (1) MISCARRIAGE ~30% (vs 10-15% background); (2) GESTATIONAL DIABETES ~3x baseline risk; (3) PRE-ECLAMPSIA ~2x baseline; (4) PRETERM BIRTH ~1.5x baseline; (5) LARGE-FOR-DATES baby / MACROSOMIA (especially if GDM); (6) C-SECTION rates slightly higher. WHAT HELPS: aspirin if other risk factors present; early GDM screening; growth scans; tight glucose control; weight management. With proactive care, most PCOS pregnancies are healthy.
Should I take aspirin in pregnancy if I have PCOS?
MAYBE — depends on other risk factors. NICE / RCOG / ACOG / USPSTF: PCOS alone is a MODERATE risk factor for pre-eclampsia. ASPIRIN 150 mg nightly from BEFORE 16 WEEKS if you have ANY of these: (1) HIGH-RISK factor (chronic high blood pressure, type 1 or 2 diabetes, kidney disease, autoimmune disease like lupus/APS, previous pre-eclampsia); (2) PCOS PLUS one or more other moderate factors (BMI ≥35, first baby, age 35+, family history of pre-eclampsia). Discuss with your midwife / consultant booking team.
When should I be tested for gestational diabetes?
EARLIER and MORE OFTEN than non-PCOS women. UK NHS / RCOG / NICE: (1) BOOKING (~8-12 weeks): HbA1c + fasting glucose to catch undiagnosed diabetes. (2) EARLY OGTT (~16-18 weeks) if HbA1c borderline or BMI ≥35. (3) STANDARD 24-28 WEEK 75g OGTT for everyone with PCOS. (4) IF GDM develops: continue insulin / metformin / diet management; postpartum 6-12 week OGTT; annual HbA1c thereafter. Why earlier? PCOS triples GDM risk through insulin resistance. Early diagnosis lets you control glucose before baby grows too big.
Should I continue metformin in pregnancy?
Depends on why you're on it. IF metformin GOT YOU PREGNANT (used as fertility treatment for PCOS): RCOG suggests CONTINUE through first trimester — possible (but unconfirmed) miscarriage reduction. Stop at 12 weeks unless GDM develops or BMI ≥35. IF metformin is for DIABETES (not just PCOS): CONTINUE through pregnancy alongside insulin if needed. IF you've never taken metformin and have PCOS: don't routinely start in pregnancy — evidence doesn't support starting. The INSIGHT 2024 trial showed no clear benefit. SPEAK with obstetric / endocrine team if uncertain.
Will my baby have PCOS?
DAUGHTERS of women with PCOS have higher chance of developing PCOS themselves — ~30-50% lifetime risk vs ~10% in general population. SONS may have higher metabolic syndrome / insulin resistance risk. NOT a direct genetic inheritance — multifactorial (multiple genes + environment). Early lifestyle support, healthy weight, regular movement, balanced diet can reduce risk in next generation. Watch for first-period irregularities, acne, hair pattern from puberty — early diagnosis lets early management.
Will I lose weight after baby with PCOS?
Postpartum weight loss is SLOWER with PCOS due to insulin resistance + hormonal factors. BREASTFEEDING helps (burns ~500 kcal/day if exclusive). GRADUAL LOSS sustainable better than crash diets. STRATEGIES: protein-rich meals; reduce refined carbs / sugar; some movement most days; sleep when possible (sleep deprivation worsens insulin resistance — challenge with newborn); support from dietitian if available. AVOID self-critical talk — postpartum bodies are doing important work. Slow + steady wins; can take 12-18 months for full PCOS-affected weight loss.
Can I breastfeed with PCOS?
YES — most women with PCOS can breastfeed normally. POTENTIAL CHALLENGES: (1) DELAYED LACTOGENESIS (milk 'coming in') may take ~3-5 days vs 2-3 days; (2) LOWER MILK SUPPLY in some (linked to insulin resistance / hormone imbalance); (3) PCOS-RELATED OVERWEIGHT / OBESITY can affect supply via hormonal pathways. STRATEGIES: early skin-to-skin; frequent feeding (every 2-3 hours including night); LACTATION CONSULTANT support EARLY; metformin can continue while breastfeeding (small amounts safe); some get domperidone if supply low (specialist decision). DON'T BLAME YOURSELF — biology can be tough.
Will my periods come back after baby?
EXCLUSIVELY BREASTFEEDING: periods may stay away for 6-18 MONTHS+ (lactational amenorrhoea). PCOS periods often DON'T COME BACK quickly even after weaning. RANGE: from regular cycles within months to no periods for 1-2+ years. DURING this no-period phase: CAN STILL OVULATE without warning — important for contraception planning if not trying for another baby. POSTPARTUM CONTRACEPTION needed even with PCOS. SEE /calculators/postpartum-contraception.
Does pregnancy 'cure' PCOS?
NO. PCOS is a lifelong condition. Pregnancy is a temporary hormonal shift but PCOS returns postpartum. SOME WOMEN find: (1) DIFFERENT symptom pattern after pregnancy — sometimes better, sometimes worse; (2) METABOLIC IMPROVEMENT if weight management successful postpartum; (3) MENSTRUAL improvement if cycles regulate more after pregnancy. SHOULD CONTINUE PCOS care lifelong — annual HbA1c, lipid check, blood pressure, mental health screening, weight management. PCOS increases type 2 diabetes risk 4-7x — long-term metabolic care essential.
What about mental health and PCOS in pregnancy?
PCOS is associated with 2x baseline DEPRESSION + ANXIETY rates. PREGNANCY can intensify. ALSO COMMON: eating disorder history (atypical patterns common); body image distress; fertility-journey grief carrying into pregnancy. CARE: EPDS / GAD-7 screening at booking, 28 weeks, postpartum. SUPPORT options: GP, perinatal mental health team, counselling. IMPORTANT: avoid weight-stigmatising language from healthcare team — push back gently if needed. Mind charity, PCOS UK, Verity (PCOS support charity) all useful. You're not alone.
Will I have growth scans?
YES — typically MORE THAN standard pregnancy. ROUTINE: 11-14 week (dating + nuchal); 20 week (anomaly); 28, 32, 36 weeks (growth) if PCOS + BMI ≥30 or GDM develops. WHY: PCOS + GDM + raised BMI increases LGA (large-for-gestational-age) and macrosomia. EFW (estimated fetal weight) >90th centile prompts review of glucose control. >95th centile or >4.5 kg estimated at term may prompt discussion of delivery timing (37-39 weeks if macrosomia confirmed). C-SECTION discussion if EFW >4.5 kg (NICE NG3 GDM guideline).
Anything I can do BEFORE getting pregnant?
YES — preconception care is high-yield in PCOS. (1) FOLIC ACID 400 mcg from 3 months before trying; 5 mg/day if BMI ≥30 or T2DM. (2) HBA1C below 48 mmol/mol (6.5%) if any insulin resistance. (3) WEIGHT MANAGEMENT — even 5% loss improves ovulation. (4) METFORMIN if PCOS-related infertility — speak to fertility specialist. (5) LIFESTYLE: nutrient-dense diet, regular movement, alcohol/smoking cessation. (6) MENTAL HEALTH check-in. (7) DEAL with any IRREGULAR / no periods via GP. (8) THYROID screen at preconception (PCOS often co-exists with thyroid issues).
How does this relate to other calculators on BumpBites?
Companion: /calculators/aspirin-pe-prevention for pre-eclampsia prophylaxis decision; /calculators/gdm-ogtt + /calculators/gct-50g for GDM diagnosis; /calculators/insulin-pregnancy for managing GDM if it develops; /calculators/pregnancy-bmi for BMI status; /calculators/postpartum-contraception for postpartum method choice (LARC well-tolerated in PCOS); /calculators/postpartum-thyroiditis for thyroid issues; /calculators/postpartum-weight-loss for the recovery phase.