Pregnancy causes many changes in the physiology of the female patient. These alterations are sometimes subtle but can lead to disastrous complications if proper precautions are not taken during dental treatment. These physiological changes that occur are due to increase in maternal and fetal requirements for the growth of the fetus and the preparation of the mother for delivery. Increased hormonal secretion and fetal growth induce several systemic, as well as local physiologic and physical changes in a pregnant woman. Local physical changes occur in different parts of the body, including the oral cavity. These collective changes may pose various challenges in providing dental care for the pregnant patient. Treatment of the pregnant patient has the potential to affect the lives of two individuals (the mother and the unborn fetus).
- Cardiovascular changes - Increased uterine mass causes compression of IVC leads to venous stasis and increased risk for deep venous thrombosis, Decreased amplitude of T-waves on electrocardiogram, Extra heart sounds / systolic S3 murmur.
- Hematologic changes - Hypercoagulable state leads to increased risk for thrombosis/embolism, Leukocytosis, Physiologic anemia due to increased circulating volume, Generalized immunosuppression.
- Respiratory changes - Increased mucosal fragility / increased risk of airway edema, epistaxis with manipulation of nasal airway, Decreased PaO2 while supine leads to increased risk of hypoxia, decreased functional residual capacity,progesterone-induced hyperventilation.
- Gastrointestinal changes - Loss of lower esophageal sphincter tone leads to increased risk of reflux disease, Decreased gastric motility, Increased intragastric pressure.
- Genitourinary changes - Loss of intravascular protein causes decreased oncotic pressure leads to peripheral edema, Increased glomerular filtration rate Urinary stasis leads to increased risk of urinary tract infections.
- Endocrine changes - Increase in Estrogen ,progesterone, thyroxine, steroids, insulin levels and increase in the circulating 1,25, dihydroxy-cholecaliciferol.
Oro-Facial Changes And Its Importance:
Oral changes include gingivitis, gingival hyperplasia, pyogenic granuloma, and salivary changes.Increased facial pigmentation is also seen. Elevated circulating estrogen,which causes increased capillary permeability, predisposes pregnant women to gingivitis and gingival hyperplasia.
Pregnancy does not cause periodontal disease but does worsen an existing condition. Increased angiogenesis, due to sex hormones coupled with gingival irritation by local factors such as plaque, is believed to cause pyogenic granuloma in 1%-5% of patients, which occurs during the first and the second trimesters and may regress after the child's birth. Due to increase in salivary estrogen the proliferation and desquamation of the oral mucosal cells provide a suitable environment for bacterial growth which predisposes the pregnant woman to dental caries.
Good oral hygiene will help to prevent or reduce the severity of the hormone-mediated inflammatory oral changes. Facial changes as "mask of pregnancy," appearing as bilateral brown patches in the mid-face begin during the first trimester and are seen in up to 73% of pregnant women. Melasma usually resolves after parturition. Preterm low birth weight baby reported with periodontal disease. It seems to be an independent risk factor and was decreased by good oral hygiene and periodontal treatment.
Pharmacotherapy in pregnancy:
Certain drugs are known to cause miscarriage, teratogenicity, and low birth weight of the fetus. Most drugs are excreted in breast milk, exposing the newborn to the drugs. toxicity to new born depends on the chemical properties, dose, frequency, duration of exposure to the drugs, and amount of milk consumed. These drugs have been categorized by FDA as follows
- Category A - Controlled human studies indicate no apparent risk to the fetus. The possibility of risk to the fetus is remote.
- Category B - Animal studies do not indicate fetal risk. Well-controlled human studies have failed to demonstrate a risk.
- Category C - Animal studies show an adverse effect on the fetus but there are no controlled studies in humans. The benefits from use of such drugs may be acceptable.
- Category D - Evidence of human risk, but in certain circumstances the use of such a drug may be acceptable in pregnant women despite its potential risk.
- Ctegory X - Risk of use in pregnant women clearly outweighs possible benefits.
- Teratogens - Effects on Fetus.
Drugs that commonly used and their effects on pregnant women and fetus-
Drugs use in pregnancy use in lactation Remarks
Antibitics
- Amoxicillin Yes Yes
- Metronidazole Yes Yes
- Erythromycin Yes Yes
- Penicillin Yes Yes
- Cephalosporins Yes Yes
- Gentamycin Yes Yes Fetal ototoxicity with gentamycin.
- Clindamycin Yes Yes
- Tetracycline No No Discoloration of teeth with tetracycline.
- Chloramphenicol No No Maternal toxicity/fetal death with chloramphenicol
Analgesics use in pregnancy use in lactation Remarks
- Acetaminophen Yes Yes
- Morphine Yes Yes Respiratory depression with morphine
- Meperidine Yes Yes
- Oxycodone With caution With caution
- Hydrocodone With caution With caution
- Propoxyphene With caution With caution
- Pentazocinet With caution With caution
- Aspirin Not in 3rd trimester No Postpartum hemorrhage associated with aspirin.
- Ibuprofen Not in 3rd trimester No
- Naproxen Not in 3rd trimester No
Antifungals use in pregnancy use in lactation Remarks
- Clotrimazole Yes Yes
- Nystatin Yes Yes
- Fluconazole With caution With caution
- Ketoconazole With caution With caution Fetal toxicity with ketoconazole.
Local Anesthetics use in pregnancy use in lactation Remarks
- Lidocaine Yes Yes
- Prilocaine Yes Yes
- Etidocaine Yes Yes
- Mepivacaine With caution Yes Fetal bradycardia
- Bupivacaine With caution Yes Fetal bradycardia
Corticosteroids use in pregnancy use in lactation Remarks
- Pednisolone Yes Yes
Sedative/Hypnotic use in pregnancy use in lactation Remarks
- Nitrous oxide Not in 1st trimester yes Spontaneous abortions with Nitrous oxide.
- Barbiturate No No
- Benzodiazepines No No Cleft lip/palate with Benzodiazepines
Certain teratogenic agents causes birth defects in the fetus andother abnormalities which are listed below
Teratogens Effects On Fetus
- Ethyl alcohol Fetal alcohol syndrometrL,
- Tobacco Low birth rate, cleft lip and palate
- Cocaine Cognitive delay, Placental abruption
- Thalidomide Thalidomide-
- Methyl mercury Microcephaly, Brain damage
- Anticonvulsants (all) Orofacial clefts, cardiac Malformations,Carbamazepine Spina bifidaial
- Valproic acid Neural tube defects
- Lamotrigine Neural tube defects
- Phenobarbital Urinary malformation
- Topiramate Abnormalities in all subjects
- Warfarin (eg, Coumadin) Warfarin embryopathy (midface and long bone deficiency) spontaneousabortion.
- ACE- inhibitors Oliguria, renal dysgenesis, lung and limb abnormalities
- Retinoids Spontaneous abortion Multiple malformations.
Pregnant patient management guidelines during dental treatments:
Initial assessment include comprehensive review of the patient's medical and surgical history. All elective procedures should be postponed until postpartum.Minor/outpatient oral and maxillofacial surgical procedures should follow some basic guidelines.
The supine position should be avoided for a variety of reasons:
1.To avoid the development of the "supinehypotensive syndrome" in which a supine position causes a decrease incardiac output, resulting in hypotension, syncope, and decreased uteroplacentalperfusion.
2. In addition, the supine position may cause a decreasein arterial oxygen tension (PaO2) and increase the incidence ofdyspepsia from gastoresophageal reflux secondary to an incompetent loweresophageal sphincter.
3.Finally, the supine position poses an increasedrisk of developing DVT, by compression of the inferior vena cava, leading tovenous stasis and clot formation.
4. The ideal position of the pregnant patient in the dental chair is the left lateral decubitus position with the right buttock and hip elevated by15°.
Radiographs, Pregnancy, And the Fetus:·
- A radiation dose of 10Gy (5 Gy in the first trimester, when organogenesis is initiated) causes congenital fetal abnormalities.·
- It has been estimatedthat the dose to the fetus is approximately 1/50,000 of that to the mother'shead in any of the exposure ranging from full mouth x-ray to CT images of headand neck. ·
- The exposure of anyradiographic films required for management of the pregnant patient in mostsituations should not place the fetus at increased risk. ·
- Adequate shielding andprotective equipment must be used at all times.
First trimester (conception to 14thweek): ·
The most critical andrapid cell division and active organogenesis occur between the second and theeighth week of post conception. · Therefore, the greaterrisk of susceptibility to stress and teratogens occurs during this time and 50%to 75% of all spontaneous abortions occur during this period.
The recommendations are:
- Educate the patient about maternal oral changes during pregnancy.
- Emphasize strict oral hygiene instructions and thereby plaque control.
- Limit dental treatment to periodontal prophylaxis and emergency treatments only.
- Avoid routine radiographs. Use selectively and when needed.
Second trimester (14th to 28th week):·
Organogenesis iscompleted and therefore the risk to the fetus is low. ·
Some elective andemergent dentoalveolar procedures are more safely accomplished during thesecond trimester.
The recommendations are:
- Oral hygiene instruction, and plaque control. Scaling, polishing, and curettage may be performed if necessary.
- Control of active oral diseases, if any.
- Elective dental care is safe.
- Avoid routine radiographs. Use selectively and when needed.
Third trimester (29th week untilchildbirth):·
Although there is no risk to the fetus during this trimester, the pregnant mother may experience an increasing level of discomfort.
Short dental appointments should be scheduled with appropriate positioning while in the chair to prevent supine hypotension. ·
It is safe to performroutine dental treatment in the early part of the third trimester, but from themiddle of the third trimester routine dental treatment should be avoided.
The recommendations are:
- Oral hygiene instruction, and plaque control. Scaling, polishing, and curettage may be performed if necessary.
- Avoid elective dental care during the second half of the third trimester.
- Avoid routine radiographs. Use selectively and when needed.
Conclusion
- it is important to remember that treatment is being rendered to two patients: mother and fetus.
- All treatment should be done only after consultation with the patient's gynecologist.
- It is best to avoid drugs and therapy that would put a fetus at risk in all women of child-bearing age or for whom a negative pregnancy test has not been ensured.
- Oral and maxillofacial surgeons should avoid elective surgery inthe pregnant patient, if possible.
- Routine dental health procedures should be accomplished before conception in planned pregnancies and during the middle trimester in unplanned pregnancies.
- Oral and maxillofacial surgeons may be called on to treat urgent or emergency cases involving trauma, infection, and pathology whose treatment cannot be postponed.
- Active treatment is directed toward optimizing maternal health while minimizing fetal risk