Pregnancy complications

Pregnancy complications

This is the last article from the series relating about important aspects about pregnancy. Complications can occur during pregnancy, but the good piece of news is that a good management of them leads to a happy story.

During pregnancy, changes in physiology occur (read more about them here) and they can precipitate a number of complications which, if left untreated, may be detrimental to the mother and/or the unborn child. Antenatal checks are essential to detect potential complications early, thus enabling optimal management and reducing the risk of morbidity and mortality.

Hyperemesis (nausea and vomiting) in pregnancy usually starts in the first trimester and tends to resolve by week 20, but may continue beyond this. It affects about 70% of women. Only around 1% experience hyperemesis gravidarum, typically defined as severe nausea and vomiting, which can result in significant dehydration, weight loss or ketonuria and often leading to hospitalisation. The aetiology of this nausea and vomiting, although not fully understood, is likely to be multifactorial, resulting from a combination of physiological, psychological and social factors.

In general, those most at risk of nausea and vomiting tend to be:

  • young
  • primiparous
  • non-smokers
  • from low socioeconomic backgrounds

Physiological changes in pregnancy, such as raised human chorionic gonadotropin (hCG) levels and transient hyperthyroidism, have been associated with nausea and vomiting; however, where symptoms persist, other causes such as infections (e.g. urinary tract infection) or gynaecological pathologies (e.g. ovarian cysts) should be excluded.

Management of nausea and vomiting is preferred through non-pharmacological measures, such as:

  • eating smaller meals more frequently
  • avoiding spicy foods and caffeine
  • preventing fatigue and ensuring women have access to appropriate emotional support.

Some women may benefit from non-pharmacological treatments such as acupressure (P6) wrist bands or the use of ginger, although evidence of their efficacy is limited.

In more severe cases, pharmacological management may be necessary. In general, the preferred first-line drug therapy is with an antihistamine. In severe cases, intravenous fluids are likely to be necessary to manage dehydration. There is no such thing like a 100% safe medicine taken during pregnancy, remember? So, avoid taking medicines during this period, if possible.

Supportive care should also be considered, including nutritional supplements such as folic acid, thiamine should be taken to prevent Wernicke’s encephalopathy. This is thought to be precipitated by the use of intravenous glucose-containing fluids, and therefore is not the fluid of choice for rehydration.

Acid reflux or heartburn is common in pregnancy and affects up to 80% of women. Symptoms are primarily managed through avoidance of trigger factors, such as:

  • foods that are spicy or have a high fat content
  • limiting portion sizes
  • avoiding tight clothing
  • stopping smoking (where relevant)

If treatment is necessary, antacids with or without an alginate should be used first-line Patients should be advised that aluminium compounds can have a constipating effect, whereas magnesium-based preparations are more likely to cause loose stools. Where these are insufficient, ranitidine or omeprazole are widely used in pregnancy and are unlikely to cause harm to the foetus.

Anaemia, particularly iron-deficiency anaemia, risk is increased in pregnancy because of the increase in the number of circulating red blood cells. For most women, this risk is offset by an increase in iron absorption seen in pregnancy by around three-fold. There is also an increased demand for folic acid and vitamin B12, although deficiency is less common. Women should be advised to eat a diet rich in essential vitamins and iron, and where necessary supplemented, particularly when their diet is felt to be lacking or there is evidence of deficiency (e.g. vegans).

Folic acid deficiency is associated with an increased risk of neural tube defects, in particular spina bifida, and therefore all women trying to conceive are advised to take folic acid daily from pre-conception to the end of the first trimester. For women at increased risk of deficiency, including those on anti-folate drug therapy (e.g. anti-epileptics), a higher dose is recommended.

Hypertension and pre-eclampsia remain one of the greatest causes of maternal and perinatal mortality and morbidity worldwide. Normally in pregnancy there is an initial decline in blood pressure that gradually increases to pre-pregnant levels later on. However, there is an increasing tendency for raised blood pressure during pregnancy.

Pregnancy-induced hypertension (PIH) is an increase in blood pressure above a threshold of 140/ 90mmHg that occurs beyond 20 weeks gestation and resolves on delivery. PIH occurs in around 10% of pregnancies. Pre-eclampsia, defined as hypertension accompanied by pregnancy-induced proteinuria, affects 2–8% of pregnancies worldwide. In severe cases, this can lead to convulsions or eclampsia. Pregnant women should have their blood pressure monitored at each antenatal check-up, as well as having their urine dipped to test for protein, to enable early detection of PIH and pre-eclampsia.

Women at risk of pre-eclampsia:

  • hypertensive disease during a previous pregnancy
  • chronic kidney disease
  • autoimmune disease (e.g. systemic lupus erythematosis or antiphospholipid syndrome)
  • type 1 or type 2 diabetes
  • chronic hypertension
  • More than one of: first pregnancy, aged 40 or older, pregnancy interval of more than 10 years, BMI of 35 or more, family history of pre-eclampsia, multiple pregnancy.

ACE inhibitors and angiotensin-II receptor antagonists should be avoided in pregnancy, as treatment can lead to oligohydramnios (reduced amniotic fluid) and theoretically adversely affect neonatal renal function. Medicines that can be used are from beta-blockers class, from calcium channels antagosnists class, or from the antiadrenergics, centrally acting class. Of course, this decision should be made by the doctor, with the mother’s consent. Women are closely monitored throughout pregnancy and in the period postpartum at which point blood pressure usually returns to normal within a couple of weeks.

Gestational diabetes (widely approched here) incidence in pregnancy, as with hypertension, is increasing year on year, linked to the increased incidence of obesity. Gestational diabetes occurs in about 5% of pregnancies. Gestational diabetes is a state of hyperglycaemia triggered by pregnancy that usually resolves following delivery. However, it can persist and is likely to recur with subsequent pregnancies. At each routine antenatal check, women will have their urine dipped to test for glucose to ensure early detection. Untreated gestational diabetes increases the risk of perinatal complications such as:

  • excessive foetal growth
  • induction of labour
  • caesarean section, pre-eclampsia
  • premature birth
  • neonatal hypoglycaemia at birth

Women should be advised to make modifications to their lifestyle and diet. However, if this is unsuccessful, pharmacological treatment should be started as soon as possible to avoid complications.

VTE (Venous thromboembolism) risk increases with pregnancy because of altered homeostasis and increased circulating blood volume. Although rare, VTE is one of the most common causes of maternal mortality in the developed world.

Women should have a VTE assessment in early pregnancy, typically carried out at the booking appointment with the midwife, to establish all risk factors (see ‘Risk factors for VTE’), and repeated when her situation changes (e.g. with intercurrent illness or hospitalisation). If the woman is considered to be at increased risk, prophylaxis should be initiated with a low molecular weight heparin (LMWH). For some women, treatment may need to continue throughout pregnancy, whereas other women will only require it in the presence of transient risk factors (e.g. hyperemesis gravidarum) or a severe infection requiring hospitalisation.

VTE assessment is repeated postnatally, as risk factors associated with delivery (e.g. caesarean section, excessive postpartum haemorrhage) may trigger the need for prophylactic treatment. In most cases, postnatal prophylaxis is continued for a period of seven days, except in high-risk women, where up to six weeks of treatment may be required.

Risk factors for VTE
·         Obesity

·         Over 35 years of age

·         Reduced mobility

·         Dehydration

·         Varicose veins

·         Hyperemesis

·         Significant medical comorbidity (increased infection, cancer, heart failure, etc.)

·         Excessive postpartum haemorrhage

·         Ovarian hyperstimulation syndrome

·         Personal/ family history of VTE

·         Thrombophilia

·         Caesarean section

·         Parity ≥ 3

·         Pre-eclampsia

In women suspected of having a VTE during pregnancy, treatment with a LMWH is initiated immediately, unless contraindicated, while investigations are carried out. LMWHs are considered safe in breastfeeding because of their poor oral bioavailability and likely inactivation in the infant’s stomach. Warfarin is generally reserved only for postnatal use, as it is safe to take when breastfeeding and women may be switched to oral treatment for extended postnatal courses. The novel oral anticoagulants (e.g. dabigatran, rivaroxaban) are not currently recommended for use in pregnancy or during breastfeeding.

Obstetric cholestasis has a worldwide incidence of 0.7%, although this varies with ethnic groups, genetics and environmental factors. Patients typically present with pruritus, in the absence of a rash or any other possible cause, and on investigation will have abnormally raised liver function tests (LFTs). Primary management is to exclude any other possible cause, followed by frequent monitoring of LFTs and the pregnancy on account of the increased risk of premature birth and stillbirth.

Treatment displace bile salts and increase their rate of clearance. Antihistaminesmay be prescribed to help relieve itching, and can be used as a sedative in patients with pruritus that interrupts their sleep. Cholestasis affects vitamin K absorption and may increase the patient’s international normalised ratio (INR). These patients should be treated with a vitamin K supplement.


Well, this is the end of the articles about changes, taking medicines and complications during pregnancy. For understanding our body it is necessary to have a healthy, balanced lifestyle, especially if another inocent human being depands on us.


References:

http://www.pharmaceutical-journal.com/learning/cpd-article/pregnancy-use-of-medicines-in-managing-complications/20068831.cpdarticle

http://www.anm.ro/anmdm/


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