Pregnancy outcomes and risks – from trying to conceive to the weeks after birth
Most pregnancies result in healthy parents and babies, but every pregnancy carries some level of risk – even when both parents are healthy. Some risks are small and manageable, others need close monitoring in specialist care. This site walks through outcomes and risks from conception and IVF, each trimester, birth, and the postnatal period – in plain language.
Trying to conceive, fertility and IVF
Risk starts even before a positive test. Age, lifestyle, underlying conditions and fertility treatments all influence conception, early pregnancy loss and complications later in pregnancy.
- Older maternal age is linked with higher rates of miscarriage, chromosomal problems and complications such as pre‑eclampsia.
- Smoking, heavy alcohol use and some recreational drugs increase the risk of poor outcomes for both mother and baby.
- Very low or high BMI can affect fertility, miscarriage risk and later pregnancy complications.
- Ovarian hyperstimulation syndrome (OHSS) can occur with some stimulation protocols and needs urgent medical review.
- Multiple pregnancy (twins or more) increases risks of pre‑term birth, high blood pressure, diabetes and caesarean birth.
- IVF pregnancies may be monitored more closely, but most still result in healthy outcomes.
- Certain medicines for epilepsy, blood pressure, autoimmune disease or mood disorders may need adjustment before conception.
- Pre‑pregnancy review is important if you have diabetes, kidney disease, heart disease, clotting problems or severe obesity.
- Never stop medication suddenly without discussing this with your specialist and GP.
First, second and third trimester risks
Risks change as pregnancy progresses. Some problems are more likely early, others in late pregnancy when blood volume, blood pressure and the physical load on the body are greatest.
Conception to 12 weeks
- Higher chance of miscarriage and ectopic pregnancy.
- Severe vomiting (hyperemesis gravidarum) can cause dehydration and weight loss.
- Infections such as rubella, varicella or certain STIs can affect early development.
- Screening for chromosomal conditions (e.g. Down syndrome) often occurs in this period.
13 to 27 weeks
- Some structural problems with the baby become visible on ultrasound.
- Early signs of placenta problems or cervical weakness may be found.
- Development of gestational diabetes or emerging high blood pressure.
- Pre‑term labour is less common than in the third trimester but still possible.
28 weeks to birth
- Risk of pre‑eclampsia, growth restriction, placental abruption and stillbirth.
- Higher chance of pre‑term birth, especially with twins or underlying conditions.
- Breathing problems and sleep‑disordered breathing can worsen in late pregnancy.
- Decisions about timing and mode of birth balance risks for mother and baby.
How your health before pregnancy changes risk
Many serious complications in pregnancy are linked to chronic conditions present before conception. Knowing about them early allows referral to combined obstetric–medical or anaesthetic clinics where needed.
- Certain heart valve problems and severe heart failure can make pregnancy very high risk.
- Significant lung disease (e.g. severe asthma, pulmonary hypertension) may limit exercise capacity and oxygen levels.
- Chronic kidney disease is linked with high blood pressure, pre‑eclampsia and growth restriction.
- Poorly controlled diabetes increases risk of miscarriage, stillbirth and birth defects.
- Pre‑existing hypertension increases risk of pre‑eclampsia, stroke and placental problems.
- Clotting disorders and previous blood clots may require blood‑thinning medication in pregnancy.
- Higher BMI is associated with gestational diabetes, blood pressure problems, sleep apnoea, and more complex anaesthesia.
- Previous caesarean, bariatric or spinal surgery can affect decisions about labour and pain relief options.
- Very low BMI may be linked with nutritional issues and small‑for‑gestational‑age babies.
Birth risks and postnatal risks
A dedicated site covering induction, vaginal birth, assisted delivery, caesarean section, haemorrhage, anaesthetic options and emergency scenarios during labour and birth.
Bleeding, infection, blood clots, breastfeeding problems, postnatal depression, anxiety and rare but serious conditions such as post‑partum psychosis.
- Severe pain, heavy bleeding, fluid leakage or sudden swelling.
- Severe headache, vision changes, chest pain or difficulty breathing.
- Thoughts of self‑harm, harming others or feeling unsafe at home.