Case 44: Midtrimester complications

 

Case 44: Midtrimester complications

CASE 44: MIDTRIMESTER COMPLICATIONS

History

A 19-year-old woman has attended the emergency department with vaginal discharge. She

is 17 weeks’ gestation in her third pregnancy. The previous two pregnancies were terminated

medically in the first trimester using prostaglandins. This pregnancy was unplanned but she

is now looking forward to being a mother.

She had a small amount of bleeding at around 7 weeks, which persisted until 9 weeks.

Ultrasound scan at 7 weeks showed a single viable embryo.

She booked for antenatal care late at 13 weeks. The combined test for Down’s syndrome

showed low risk (1:5100). She has not yet felt any fetal movements in the pregnancy.

She is a non-smoker and has drunk no alcohol since finding out she was pregnant at 7 weeks.

She has no other significant medical history.

On direct questioning the vaginal loss started a few hours ago. Initially she thought it was possibly urine that was leaking but it has no smell and she is sure it is now coming from the vagina.

There has been a minimal amount of blood on the pad but it is mainly clear fluid. Initially the

fluid soaked through all of her clothes, but it is now less. There has been no abdominal pain.

Examination

She appears distressed. Her temperature is 37.1 degrees, blood pressure is 115/68 mmHg and

pulse is 84/min.

Abdominally the uterus is palpable about one-third of the way between pubic symphysis and

umbilicus and feels soft. The abdomen is non-tender.

Speculum examination shows the cervix to appear normal and closed. There is a moderate

amount of clear watery shiny fluid pooling in the speculum, which is also seen coming from

the cervix when the woman is asked to cough.

INVESTIGATIONS

Normal range for

pregnancy

Urinalysis: trace protein; no leucocytes; no nitrites

Haemoglobin 10.8 g/dL 11–14 g/dL

Mean cell volume 92 fL 74.4–95.6 fL

White cell count 6.9×109/L 6–16×109/L

Platelets 321×109/L 150–400×109/L

C-reactive protein 11.3 mg/L <10 mg/L

Questions

• What is the diagnosis?

• What is the prognosis and what should you say to the woman?

• What, if any, further investigations should be requested and what would be your

management plan?100 Cases in Obstetrics and Gynaecology

110

ANSWER 44

Diagnosis

The history and speculum findings are very highly suggestive of rupture of membranes

at 17 weeks’ gestation. This is relatively rare but the presence of persistent first-trimester

bleeding is a risk factor, probably because the blood and haemosiderin cause irritation

and ultimately necrotic breakdown of the membranes. The other likely cause is subclinical

infection. Bacterial vaginosis in particular is associated with increased risk of midtrimester

fetal loss.

! Prognosis and communication to the woman

The prognosis in such premature rupture of membranes is extremely poor. This is because

of the various factors that may ensue following membrane rupture:

1. Spontaneous miscarriage is common after rupture of membranes.

2. Chorioamnionitis is likely to develop once the integrity of the gestation sac has

been breached.

3. If miscarriage or infection does not occur, then the fetus is likely to have profound

pulmonary hypoplasia due to lack of amniotic fluid, as well as limb contractures.

Exact figures are not available but an estimate of the possibility of the woman taking

home a live baby is probably around 10–20 per cent. Therefore she must be offered a

grave prognosis for the pregnancy, with respect to not only the chance of fetal survival

but also the chance of her developing chorioamnionitis, which can be very sudden and

catastrophic.

Further investigation and management

To confirm the diagnosis and to check whether the fetal heartbeat is still present an ultrasound scan should be performed. If the fetus has died then medical evacuation of the pregnancy should be carried out without delay.

If the fetus is alive and the scan confirms anhydramnios or oligohydramnios then the woman

should be given the option of termination of the pregnancy. This would be in her best interests in terms of preventing serious maternal infection. In view of the poor prognosis for the

fetus, many women would choose this option.

If she declines termination then she should be closely monitored for symptoms and signs

of infection such as fever, shivering, ’flu type symptoms, abdominal pain, offensive vaginal

discharge or bleeding. Pyrexia >37.5°, tachycardia, hypotension or increased respiratory rate

should be looked for. Alternate-day serum C-reactive protein and white cell count should be

checked. There should be a very low threshold for recommending termination of the pregnancy if any combination of these features develops, as sepsis is a leading cause of maternal

death in the UK, with one-third of such deaths occurring before 24 weeks’ gestation.

During expectant management the fetal heartbeat should be auscultated daily to allow for

evacuation of the pregnancy if the fetus dies in utero. Whether the pregnancy is terminated

due to fetal death, maternal choice or maternal infection, the first-line method would be the

use of prostaglandin, preceded by mifepristone (a progesterone antagonist) 48 hours earlier

if time allows.Case 44: Midtrimester complications

111

KEY POINTS

• The prognosis for a baby after rupture of membranes in the second trimester is

extremely poor.

• The risks of sepsis and its consequences for the mother should be considered as

very important in counseling the woman regarding continuation of the pregnancy

after second trimester rupture of membranes.

• The woman should be advised to report any symptoms or signs of possible sepsis

and these should be acted on as soon as possible.