Oxford Handbook of Midwifery (22 page)

Fetal and neonatal infection

Useful website

British Association for Sexual Health and HIV. Available at: M www.bashh.org.uk.

Further reading

Dapaah S, Dapaah V (2009). Sexually transmissible and reproductive tract infections in pregnancy. In: Fraser D, Cooper M (eds)
Myles Textbook for Midwives
. 15th edn. London: Churchill Livingstone, pp. 415–32.

CHAPTER 3
Sexual health

40‌‌

Syphilis

• Although rare in the UK, syphilis remains a high cause of fetal and neonatal loss in developing countries, particularly Africa.
  
• The overall number of cases of infectious syphilis has increased substantially in 16–34-year old females in the UK in recent years.
  ¹
  Congenital syphilis has therefore re-emerged.
  
• It caused by the bacterium
  Treponema pallidum
  and usually acquired by sexual contact.
  
• Infection causes a complex systemic disease that can involve almost every organ in the body.
  
• It can be congenitally transmitted across the placenta.
  
• Because of the increased incidence and its devastating effects it is still routinely screened for in early pregnancy in the UK (b see Screening for syphilis, p. 58).
  
• The midwife has a responsibility for effective sexual health promotion
  and encouraging effective long-term contraception for at least two
  

  years after this pregnancy. Both the woman’s contraception and sexual
  

  health needs are best dealt with by the local specialist contraception and sexual health clinic.
  

  Stage of the infection
  

  Early infectious stage:
  

• Primary:
  occurs 9–90 days after exposure (average 21 days)
  
• Secondary
  : 6 weeks to 6 months after exposure (4–8 weeks after primary lesion)
  
• Early latent
  : 2 years after exposure. Late non-infectious stage:
  
• Late latent
  : more than 2 years after exposure with no signs or symptoms
  
• Neurosyphilis, cardiovascular syphilis, gummatous syphilis
  : 3–20 years after exposure.
  

  Syphilis in pregnancy
  

• Untreated syphilis may result in spontaneous abortion, preterm birth, stillbirth, or neonatal death.
  
• If the infant survives and, dependent on the stage of the infection in the mother, there is high risk of infant or childhood morbidity.
  
• Congenital transmission will occur from 4 months onwards and the highest risk is from 6 months onwards, once the Langhan’s layer of the early placenta has completely atrophied, which was the protective mechanism.
  
• A woman diagnosed in pregnancy is likely to have early infectious syphilis and early treatment will prevent congenital infection.
  
• Treatment is usually with a course of intramuscular penicillin. For a woman with penicillin allergy, erythromycin is the drug of choice. Tetracycline is contraindicated in pregnancy.
  

  SYPHILIS
  

  41
  

Congenital syphilis

3 months of age, allowing time for passive maternal antibodies to disappear.

Useful website

British Association for Sexual Health and HIV. Available at: M www.bashh.org.uk.

Further reading

Dapaah S, Dapaah V (2009). Sexually transmissible and reproductive tract infections in pregnancy. In: Fraser D, Cooper M (eds)
Myles Textbook for Midwives
. 15th edn. London: Churchill Livingstone, pp. 415–432.

1
Health Protection Agency (2009).
Syphilis and Lymphogranuloma venereum: Resurgent STI Infections in the UK.
Available at: M
www.hpa.org.uk/web/HPAwebfile/HPAweb_C1245581513523 (accessed 2.5.10).

CHAPTER 3
Sexual health

42‌‌

Vaginal infections

During pregnancy an increased vaginal discharge is commonly experienced and is the result of normal physiological changes related to increased blood flow in the reproductive organs, and a decrease in the acidity of the vaginal discharge. Investigation should be considered if the woman reports itching, soreness, offensive smell, or pain on passing urine.

It is important to remember that
Chlamydia trachomatis
is the most common cause of infection and 70–80% of infected women are asymptomatic. All women should be offered a routine urine-based screening test in early pregnancy and at any other time, as required.

For specific infections see the relevant chapters in this section.

Obtaining a vaginal swab

• There are two methods to obtain a vaginal swab; high vaginal and introital.
  
• Usually even though significant vaginal discharge will be apparent, it will
  possibly be contaminated so obtaining the swab from deeper in the
  

  vagina will yield a more accurate result from laboratory investigation.
  

• A self taken swab is as effective. Tell the woman to count to 60 while rotating the swab in the vagina.
  
• A high vaginal swab is obtained by viewing the upper vagina with a speculum.
  
• Having consented to the procedure and removed the necessary undergarments, the client should lie on an examination couch, bend her knees, and with her heels together let her knees fall apart. Lighting should be adjusted to give a good view of the vulva and perineum.
  
• The speculum should be warmed (if of metal construction) and lubricated, and inserted gently into the vagina with closed blades orientated in the same direction as the vaginal opening. Once inserted, the blades should be slowly rotated until they are horizontal and opened slowly, bringing the cervix into view.
  
• The swab can now be taken from the fornices of the upper vagina, avoiding contamination from the vaginal entrance.
  
• Swabs for GBS are obtained from just inside the vaginal opening. At the same time a rectal swab is usually taken. There is less emphasis on avoiding contamination, as the organism inhabits both the rectum and lower genital tract.
  

  Chapter 4
  

  43‌‌
  

  Antenatal care
  

  Confirmation of pregnancy
  44
  Adaptation to pregnancy
  46
  Blood values in pregnancy
  50
  The booking interview
  51
  Taking a sexual history
  52
  

  Principles of antenatal screening
  54
  Screening for risk in pregnancy
  56
  Antenatal screening
  57
  

  Screening for syphilis
  58
  

  HIV screening
  59
  

  The full blood count
  60
  

  ABO blood group and rhesus factor:
  

  anti-D prophylaxis for the Rh-negative mother
  62
  

  Screening for Down’s syndrome risk
  64
  

  Group B haemolytic streptococcus
  66
  

  Sickle cell anaemia
  68
  

  Thalassaemia
  70
  

  Antenatal examination
  72
  

  Abdominal examination
  74
  

  Monitoring fetal growth and well-being
  76
  

  CHAPTER 4
  Antenatal care
  

  44‌‌
  

  Confirmation of pregnancy
  

  There are a number of options for women wishing to confirm their pregnancy. A range of home pregnancy testing kits are available from pharmacies, and most pharmacies will carry out a test for a small charge. GP surgeries also provide this service.
  

  The tests are based on detecting the presence of B-human chorionic gonadotrophin (B-hCG), in the woman’s urine or blood. This hormone is secreted by trophoblast or placental tissue from around 7–10 days after conception.
  

  Other signs of pregnancy are:
  

• Amenorrhoea
  : absence of menstrual periods in a woman who normally experiences menstruation.
  
• Nausea and vomiting
  : common in the first trimester from 6 weeks’ gestation, peaking at around 10 weeks’ gestation and diminishing as the pregnancy reaches 12 weeks and beyond. It persists throughout pregnancy in some women.
  
• Frequency of micturition
  : increased urine production and pressure on
  the bladder due to the growing uterus.
  
• Tiredness
  : increased metabolic activity and rapid growth of uterine and
  

  placental tissue.
  

• Breast tenderness/changes
  : hormonal effects of oestrogen and progesterone. The breasts enlarge, become tender, and heavier.
  
• Fetal movements
  : these are a late sign, appearing in the second trimester as the fetus grows and the uterus becomes a larger abdominal organ. Early movements feel like fluttering or bursting bubbles. First-time mothers notice these later (18–20 weeks) than those undergoing a second or subsequent pregnancy (16–18 weeks).
  
• Pica
  : or craving for unusual foods, or combinations of foods— hormonal influences on the gastrointestinal tract alter the mother’s perception of taste.
  

  Dating the pregnancy
  

  Ascertain the following:
  

• The first day of the LMP. This may be difficult to ascertain accurately, unless the woman is in the habit of recording this.
  
• The length of the menstrual cycle in days and its regularity.
  
• The number of days of bleeding and if the LMP was a normal bleed.
  
• The woman’s usual method of contraception, and when this was stopped. If the LMP was a withdrawal bleed after oral contraceptive, this date is unreliable.
  

  Calculate the EDD for a 28-day cycle by adding 7 days and 9 months to date of the LMP. Make adjustments for shorter or longer cycles. b See also Taking a menstrual history, p. 16.
  

  Confirm the dates by ultrasound scan. Most women will be offered a scan at around 14 weeks’ gestation to coincide with serum fetal screening tests.
  

  CONFIRMATION OF PREGNANCY
  

  45
  

  The earlier the scan the more accurate the estimation of fetal age. If the results differ from the menstrual date by more than 2 weeks, the scan date should be accepted as the correct date and the EDD adjusted accordingly.
  

  

  Having accurate dates allows for correct interpretation of fetal screening tests and prevents unnecessary induction of labour for post-maturity.
  

  CHAPTER 4
  Antenatal care
  

  46‌‌
  

  Adaptation to pregnancy
  

  Increasing amounts of circulating hormones bring about pregnancy changes throughout the body, and all body systems are affected to a greater or lesser degree. The changes allow the fetus to develop and grow, prepare the woman for labour and delivery, and prepare her body for lactation.
  

  The reproductive system
  

• Most of the changes take place in the uterus, which undergoes hypertrophy and hyperplasia of the myometrium. The decidua also becomes thicker and more vascular.
  
• Progesterone causes the endocervical cells to secrete thick mucus, which forms a plug, called the operculum, in the cervical canal, protecting the pregnancy from ascending infection.
  
• Muscles in the vagina hypertrophy and become more elastic to allow distension during the second stage of labour.
  

  The cardiovascular system
  

  •
  Due to the increasing workload the heart enlarges.