Obstetric care during the antenatal journey: when referral to an obstetrician may be required and what to expect

In the UK, antenatal care is typically provided by midwives. Referral to an obstetrician (a doctor specialising in pregnancy and delivering babies) is only required when the pregnancy is high-risk or complex.

There can be many different reasons why a pregnancy is categorised in this way so referral to an obstetrician should not automatically be viewed as a cause for concern, but instead as an acknowledgment that there may be some complicating factors, which need specialist management to ensure that the pregnancy progresses as safely as possible.

Understanding when obstetric input might be required, and what factors prompt referral, can help expectant mothers to feel more informed and reassured that any risk factors they might have are being carefully monitored and treated seriously. It can also give mothers the confidence to advocate for referral to a specialist practitioner, if they have concerns.

Why might an expectant mother be referred to obstetric care? 

An expectant mother may be referred to the care of an obstetrician at any stage of pregnancy, but the key points where referrals are likely to be made are set out below.

At booking (8-12 weeks)

Midwives are usually the first point of contact for expectant mothers, and will conduct the initial booking appointment and take a detailed and comprehensive history. At this initial stage, the midwife will refer a mother for obstetric care if there are factors that increase the risk of complications and require specialist oversight. Factors which might prompt referral to an obstetrician may include the following:

• pre-existing conditions that could impact the pregnancy, such as:
  • diabetes
  • uncontrolled chronic hypertension
  • cardiac disease
  • renal disease
  • autoimmune disorders
  • epilepsy
  • inherited conditions such as sickle cell disease or muscular dystrophy
  • significant mental health conditions
  • BMI ≥35 or very low BMI
  • substance misuse or complex social factors
• complications in a previous pregnancy such as:
  • stillbirth or neonatal death
  • preterm birth
  • pre-eclampsia/eclampsia
  • severe fetal growth restriction
  • macrosomia (a very large baby)
  • congenital or genetic abnormalities such as a structural defect or chromosomal abnormality
  • recurrent miscarriage
  • caesarean section or uterine surgery
  • severe postpartum haemorrhage
  • blood group incompatibilities or other significant maternal antibodies, such as Rhesus isoimmunisation
  • cervical weakness or insufficiency (often caused by previous trauma or surgery, or congenital conditions, such that a cervical cerclage, known as a cervical stitch, is required to keep the cervix closed and prevent premature birth)
• if the pregnancy is a multiple pregnancy (twins, triplets or higher multiple)
• if there are concerning findings during the initial assessments such as:
  • abnormal fetal heart rate
  • persistent vaginal bleeding.

Early referral from the point of booking allows the obstetrician to identify any potential problems early, and plan appropriately tailored antenatal care. Usually the obstetrician and midwife will work together to manage the pregnancy.

Following routine screening and ultrasound findings

Obstetricians may be asked to undertake a review if abnormalities are detected during routine assessments and ultrasound scans, which may include:

• fetal structural anomalies, ranging from mild to severe, which can affect almost any part of the body, for example:
  • the heart (such as a hole in the heart, or misshaped valve)
  • neural tube (problems with the development of the brain or spinal cord, such as anencephaly (baby born without a forebrain and top of skull) or spina bifida (a gap in the spine)
  • limbs (missing or shortened limbs or clubfoot)
  • genitourinary (lower urinary tract obstructions (LUTO), missing or malformed kidneys or blockages)
  • abdominal wall (such as gastroschisis or omphalocele where organs protrude outside the body)
  • craniofacial (such as cleft lip or cleft palate)
• an increased risk of chromosomal conditions such as Downs Syndrome (too many chromosomes), Turner Syndrome (not enough chromosomes), Edwards Syndrome (an extra copy of chromosome 18), Patau Syndrome (an extra copy of chromosome 13) or Prader-Willis Syndrome (deleted genetic information on chromosome 15).
• unusual fetal growth patterns (such as very small or large for gestational age, or a change in growth trajectory)
• problems with the placenta such as placenta previa (when the placenta partially or completely covers the cervix, blocking the baby’s exit from the uterus) or a chorioangioma (a benign vascular tumour on the placenta which if large enough can divert blood away from the fetus).

In these situations, obstetricians will be able to arrange further investigations or surveillance, which might include:

• growth scans
• Doppler studies (imaging using sound waves to measure blood flow to the baby)
• amniocentesis (collection of amniotic fluid)
• chorionic villus sampling (collection of a very small piece of placenta)
• prenatal chromosomal microarray analysis (CMA) (testing the sample taken from amniocentesis or CVS)
• fetal echocardiogram (imaging of the heart using sound waves)
• fetal MRI
• fetoscopy (minimally invasive surgical technique for fetal therapy or prenatal diagnosis)
• fetal exome sequencing (ES) (genetic testing).

An obstetrician will be able to arrange the specialist testing that is required, with assistance from radiologists and sonographers, fetal medicine specialists and geneticists.

The obstetrician can then provide advice, management, counselling, and where appropriate, treatment. This may include prenatal treatment or, for some conditions, will mean ensuring that the baby is delivered in a certain setting or way, with the relevant medical professionals available to allow immediate access to specialised medical or, if necessary, surgical intervention.

When complications develop

Many pregnancies will be low-risk and suitable for midwifery-led care from the outset but, for some of these women, complications will develop at a later stage, meaning that obstetric input is then required, including for example:

• new onset hypertension (high blood pressure)
• proteinuria (protein in the urine which can be a warning sign for pre-eclampsia)
• pre-eclampsia (high blood pressure causing organ dysfunction)
• eclampsia (sudden onset of seizures)
• developing gestational diabetes
• bleeding or severe pain
• concerns about fetal growth (small or large for gestational age, change in growth trajectory, intrauterine fetal growth restriction, or suspected macrosomia)

• oligohydramnios (not enough amniotic fluid often caused by ruptured membranes, placental insufficiency, pre-eclampsia or fetal kidney or urinary tract blockages)
• polyhydramnios (too much amniotic fluid which can be caused by maternal diabetes, fetal gastrointestinal obstructions, or multiple gestations)

• reduced fetal movements
• abnormal fetal heart rate patterns
• signs of infection or chorioamnionitis
• signs of preterm labour (before 37^th week of pregnancy)
• cervical weakness, insufficiency or shortening.

The obstetrician can provide appropriate monitoring and decide what intervention, if any, is required.

For birth planning

Referral to an obstetrician later in pregnancy can also occur specifically to discuss specialised birth planning, for example when an expectant mother has had a previous caesarean section, when the baby is breech, or if there is a multiple pregnancy (twins, triplets or more).

In these situations, the obstetrician will be able to advise on the risks and benefits of different modes of delivery, so that a decision can be made about whether to proceed with vaginal delivery or schedule an elective caesarean section. For breech babies, vaginal delivery will be dependent upon meeting specific safety criteria. An obstetrician may advise in relation to performing an external cephalic version (ECV) with ultrasound monitoring, a procedure where the obstetrician will apply outside pressure to the abdomen in an attempt to turn the baby, to facilitate the possibility of a vaginal birth.

When do medical negligence claims arise in relation to obstetric antenatal care?

Most pregnancies proceed without complication, and the involvement of an obstetrician ensures that risk factors are appropriately managed. However, it is important for expectant mothers to understand the difficulties that can arise in relation to pregnancy care, so they can advocate for themselves and seek specialist input, or a second opinion, if they have concerns.

Medical negligence claims tend to arise in relation to obstetric antenatal care when:

• there has not been referral to an obstetrician when necessary
• the appropriate level of monitoring has not been undertaken
• a condition is missed, or a deterioration in a condition is not noticed and acted upon
• there is not proper advice about treatment options/lack of informed consent
• there is inappropriate birth planning.

Conclusion

The extent of an obstetrician’s involvement, if any, during pregnancy will be dependent upon each individual situation. Obstetricians generally work alongside midwives who provide the day to day care and guidance, whilst the obstetrician manages the specific risks and complications. This process usually works well, ensuring both mother and baby receive effective support, but sadly, there are some rare situations when obstetric antenatal care does go wrong, and this can have devastating consequences. If you have concerns about antenatal care that has been provided to you or a loved one, our maternity care solicitors are available for a confidential, no‑obligation consultation.

This article is part of a series produced by our specialist maternity care team which considers the different types of care provided to expectant mothers, both during the antenatal period and labour, with a view to raising awareness, improving knowledge and empowering expectant mothers and their families.