This section covers two groups of conditions:
1 skin conditions in which pregnancy is just one of a number of precipitating factors;
2 skin conditions unique to pregnancy.
Acne, erythema multiforme, erythema nodosum and generalised pustular psoriasis form the first group.
Pre-existing acne may deteriorate during pregnancy, but may also present anew. Erythema multiforme and erythema nodosum are both caused by a multitude of other aetiological factors, which must be excluded before it is possible to attribute the onset to pregnancy alone. Generalised pustular psoriasis describes a superficial sterile eruption occurring on the background of widespread erythema, which is asso-ciated with fever, systemic upset and hypocalcaemia (with tetany) in the more severe cases. It carries significant peri-natal mortality and is more common in those with a history of plaque psoriasis. A clinically identical condition called impetigo herpetiformis was previously thought to be a preg-nancy-specific dermatosis, but the two are now considered the same condition. Pregnancy appears to be one of a number of triggers for generalised pustular psoriasis.
Box 18.1 Examples of inheritable skin disorders Autosomal dominant
Ichthyosis hystrix and vulgaris Palmoplantar hyperkeratosis (tylosis) Epidermolysis bullosa simplex Ectodermal dysplasia (some forms) X-linked recessive
X-linked icthyosis
Hypohidrotic ectodermal dysplasia Multifactorial
Atopic eczema (the risk of some allergic problems may reach 50% in the offspring of a couple with one affected person; the risks are higher where both parents are eczema sufferers) Psoriasis (the children of two psoriatic parents have a risk of approximately 50% of being affected themselves)
Box 18.2 Dermatological treatments to be avoided during pregnancy Acitretin and tazarotene (retinoids used in psoriasis)
Isotretinoin (retinoid used to treat severe acne) Griseofulvin (antifungal treatment)
Methotrexate (antimetabolite used to treat psoriasis) Podophyllin (used for genital warts)
Tetracycline (used for skin infections/acne) Thalidomide (leprosy treatment)
150 Dermatological conditions
ANTENATAL OBSTETRICS Table 18.1 Pregnancy-specific dermatoses NameIncidenceOnsetResolutionClinical featuresHistologyImmunofluo rescenceFetal effectsRecurrenceManagementAssociated conditions Polymorphic eruption of pregnancy (pruritic urticarial papules and plaques of pregnancy, toxaemic rash of pregnancy, toxic erythema of pregnancy) 1 in 25027–40 weeks (usually late third trimester)
Usually within 2 weeks of delivery
Red urticarial papules and plaques. Rarely, vesicles and target lesions. Begins abdominally within striae Umbilical sparing May spread to thighs and occasionally limbs Epidermal/ dermal oedema Perivascular infiltration Patchy parakeratosis NegativeNoneUncommonCalamine lotion 1% hydrocortisone aqueous cream Antihistamines Systemic steroids
None Pemphigoid gestationis (herpes gestationis)
1 in 3000–60,000Second/third trimester (occasionally postpartum) Few weeks postpartum to 1 year
Erythematous urticarial plaques. Vesicles and bullae form at the centre or periphery of plaques. Often begins periumbilically. Spreads to trunk and extremities Perivascular inflammation Subepidermal blister
PositivePossible increased risk of IUGR and preterm labour CommonModerate/ strong topical steroids Systemic steroids Antihistamines
Graves’ disease and other autoimmune conditions Prurigo of pregnancy1 in 30025–30 weeksSeveral monthsNo urticated lesions Multiple excoriated papules Abdomen and limbs
See polymorphic eruption of pregnancy NegativeNoneRecordedAqueous cream Topical steroids Antihistamines
Atopy Pruritic folliculitis of pregnancy
UncertainSecond/third trimesterWithin 2 weeks of delivery
Masses of itchy red follicular papulesNon-specific folliculitisNegativeNoneUncertainTopical 10% benzoyl peroxide Mild topical steroids Antihistamines
None
ANTENATAL OBSTETRICS Dermatoses precipitated by pregnancy 151
This leaves four reasonably well-defined dermatoses found only in pregnancy (Table 18.1).
A diagnosis can usually be made on clinical grounds alone; however, pemphigoid gestationis can be confused with polymorphic eruption of pregnancy if there are no vesicles present. The two conditions are easily distinguished by immunofluorescence studies of skin biopsies. Pemphigoid gestationis is characterised by C3 deposition along the epidermal/dermal junction. IgG deposition is usually another feature, the target protein being a 180-kDa component of hemidesmosomes. Immunofluorescence studies are negative in polymorphic eruption of pregnancy. Clinical distinction is appropriate as pemphigoid gestationis has been linked to increased rates of stillbirth, IUGR and preterm labour [D].
Although this may represent biased reporting of poor outcomes, extra surveillance would seem warranted in these pregnancies [E].
Key References
1. Schiff BL, Kern AB. A study of postpartum alopecia. Arch Dermatol 1963;87:609.
2. Winton GB. Skin diseases aggravated by pregnancy. J Am Acad Dermatol 1989;20:1–13.
3. Perlman SE, Rudy SJ, Carissa P, Townsend-Akpan C.
Caring for women with childbearing potential tak-ing teratogenic dermatologic drugs. J Reprod Med 2001;46(Suppl 2):153–61.
Chapter 19 Drug and alcohol misuse
Louise Kenny
INTRODUCTION
The incidence of substance misuse in the UK varies widely by geographical location. Three per cent of under-35s in the UK are said to have a drug problem, although London, Glasgow, Liverpool and Manchester have traditionally been considered
the ‘hotspots’. However, a recent cross-sectional audit of health records in a London specialist perinatal addictions outreach service reported that a total of 167 pregnant substance-using women were referred between 2002 and 2005. Compared with 1989–1991, there were significantly more pregnant women presenting at an older age, later gestation, with increased polysubstance use and a higher percentage of women from black or minority ethnic communities. Clearly the problem is increasing, and maternity services must have local guidelines and action plans in place to manage it. Alcohol is a particular concern. Recent data from a global cohort study of low-risk first-time mothers found that 34 per cent of women reported binge alcohol consumption in the 3 months before pregnancy, and 23 per cent of these participants reported binge alcohol consumption during the first 15 weeks of pregnancy.1
There is a tendency to focus attention on the medical aspects of substance abuse in pregnancy. Although these drugs may involve actual harm to the pregnancy, the associ-ated social and health problems are as important, if not more so. Throughout this chapter it will become clear that separat-ing the two is very difficult, and the contributions made first by the drugs themselves and second by the socio-economic environment are almost impossible to disentangle. Separating the two is of greater theoretical than practical importance.
Substance-exposed pregnancies are ‘high risk’, and tailored antenatal care must be provided that tackles all the problems, both social and medical.
Substances of abuse are rarely used in isolation.
‘Polysubstance’ misuse is the norm, and heavy alcohol consumption and tobacco smoking compound the harm done by classified drugs. The following discussion there-fore does not tackle each drug independently, but aims to explore their individual contributions to each problem encountered in the pregnancy. Many studies demonstrating harmful effects of substance abuse in pregnancy are retro-spective and little or no effort is made to control for con-founding factors. Clearly, there are no randomised studies.
Better study design is often associated with negative results or a diminution in the harm reported. There is little doubt, however, that drug use during pregnancy is linked to poorer outcomes.
MRCOG
The RCOG has published statement No. 5, Alcohol Consumption and the Outcomes of Pregnancy (March 2006), and this is referred to where appropriate.
Relevant standards
To understand and demonstrate appropriate knowledge, skills and attitudes in relation to pregnant women who misuse alcohol and drugs.
Theoretical skills
Awareness of drug and alcohol misuse in pregnancy:
• Knowledge of the pharmacological actions of opioids, cocaine, marijuana, amphetamines, benzo-diazepines and alcohol.
• Appreciate the acute and chronic maternal effects and associations of substance abuse to optimise recognition and management during pregnancy.
• Understand the fetal/neonatal effects of in utero exposure to these substances.
• Recognise the association between substance abuse and other health and social problems.
Practical skills
• Provide pre-conception counselling to a woman with a history of alcohol or drug misuse.
• Manage a pregnancy complicated by substance abuse.
• Liaise with social and specialist drug services to individualise care.
Maternal effects 153
ANTENATAL OBSTETRICS