History of Present Pregnancy:

The last menstrual period is recorded and the gestation adjusted for cycle length. In the UK, early pregnancy ultrasound is used to date all (except IVF) pregnancies, although the evidence for this is poor.

Past Obstetric History:

Many obstetric disorders have a small but significant recurrence rate. These include preterm labour, the small-for-dates and the ‘growth-restricted’ fetus [→ p.216], stillbirth, antepartum and postpartum haemorrhage, some congenital anomalies, rhesus disease, pre-eclampsia and gestational diabetes.

Past Gynaecological History:

A history of subfertility increases perinatal risk; if fertility drugs or assisted conception have also been used, the likelihood of a multiple pregnancy is also increased. Women with previous uterine surgery (e.g. myomectomy) are usually delivered by elective Caesarean section. A cervical smear history is taken.

Past Medical History:

Women with a history of hypertension, diabetes, autoimmune disease, haemoglobinopathy, thromboembolic disease, cardiac or renal disease, or other serious illnesses are at an increased risk of pregnancy problems and need input from the appropriate specialist. Direct questions regarding depression are recommended.

Drugs:

Drugs that are contraindicated in pregnancy should be changed to those considered to be safe. Ideally, this should have occurred at a preconceptual counselling visit.

Family History:

Gestational diabetes is more common if a first-degree relative is diabetic. Hypertension, thromboembolic and autoimmune disease, and pre-eclampsia are also familial.

Immigration and Language Issues:

access to appropriate information and advice is essential.

Personal/Social History:

Smoking, alcohol and drug abuse are sought. The possibility of domestic violence should always be considered.

Examination

General health and nutritional status are assessed. The BMI is calculated: if >30 (20% of women), maternal and fetal complications are more common. A baseline blood pressure enables comparison if hypertension occurs in later pregnancy. If pre-existing hypertension is found, the risk of subsequent pre-eclampsia is increased. Incidental disease such as breast carcinoma may occasionally be detected.

Abdominal examination before the third trimester is limited. Once the uterus is palpable (about 12 weeks), the fetal heart can be auscultated with an electronic monitor. Routine vaginal examination and clinical assessment of pelvic capacity are inappropriate at this stage. If a smear has not been performed for 3 years it is usually done 3 months postnatally.

Booking Visit Investigations

Ultrasound Scan

Ultrasound between 11 and 13+6 weeks should be offered. In the UK, NICE recommends that all women, irrespective of the certainty of their last menstrual period, are dated using crown–rump length (CRL) if <14 weeks (unless the pregnancy is from IVF). In spite of this, where the CRL is equivalent to ±5 days calculated from a certain LMP and a regular menstrual cycle, many women are more accurate. This scan also detects multiple pregnancy and enables screening for chromosomal abnormalities with nuchal translucency measurement [→ p.153], in conjunction with blood levels of human chorionic gonadotrophin beta-subunit (β-hCG) and pregnancy-associated plasma protein A (PAPPA), as the ‘combined test’ [→ p.157].

Blood Tests

A full blood count (FBC) check identifies pre-existing anaemia.

Serum antibodies (e.g. anti-D) identify those at risk of intrauterine isoimmunization [→ p.198].

Glucose Tolerance Test:

in women at risk, this is planned for later in the pregnancy [→ p.183].

Blood tests for syphilis are still routine because of the serious implications for the fetus.

Rubella immunity [→ p.166] is checked: vaccination, if required, will be offered postnatally.

Human immunodeficiency virus (HIV) and hepatitis B counselling and screening is offered [→ p.168].

Haemoglobin electrophoresis is performed in all women. Sickle-cell anaemia is common in Afro-Caribbean women; the thalassaemias in Mediterranean and Asian women [→ p.195]. The partner can be tested if the woman is a carrier, to identify women who should be offered prenatal diagnosis.

Other Tests

Screening for infections implicated in preterm labour (e.g. Chlamydia, bacterial vaginosis [→ p.205]) could be performed at this stage, in women at increased risk.

Urine microscopy and culture are performed because asymptomatic bacteruria in pregnancy commonly (20%) leads to pyelonephritis.

Urinalysis for glucose, protein and nitrites screen for underlying diabetes, renal disease and infection, respectively.

Health Promotion and Advice

Drugs

Medications are generally avoided in the first trimester, but teratogenicity is rare. Regular medication should ideally be adjusted preconceptually.

Folic acid supplementation, with 0.4 mg/day folic acid, should continue until at least 12 weeks. Vitamin D,

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