Pregnancy and Dentistry Overview

Pregnancy and Dentistry

• Dental practitioners need to understand and diagnose pregnancy-specific diseases and conditions.
• They should consider the pathophysiological aspects relevant to dentistry when treating pregnant patients.
• A safe and effective treatment plan, beneficial to both the mother and the fetus, is crucial.

Stages of Pregnancy

• First trimester (1-12 weeks/first 3 months): Focus on fetal organ formation; avoid elective dental treatments whenever possible.
• Second trimester (13-24 weeks/3rd to 6th month): Ideal time for preventive and interceptive dental care due to fetal growth and maturation.
• Third trimester (25-40 weeks/6th to 9th month): Potential concerns about fetal and maternal health (e.g., parturition). Dental treatments should be short and limited to emergencies to prevent stress on the expectant mother.

Physiological Changes During Pregnancy

• Pancreatic insulin changes: Human placental lactogen (hPL) conserves blood glucose for neonates and can cause gestational diabetes mellitus (GDM). GDM elevates maternal and infant morbidity risks (e.g., preeclampsia). Periodontitis is aggravated by inflammatory response relating to insulin resistance caused by hPL. Tooth mobility may increase. Pregnancy does not cause periodontitis but aggravates existing ones.
• Adrenal gland secretions: Increased estrogen, progesterone, and cortisol (steroids). Increased steroids in the first trimester can lead to pregnancy granuloma formation. Lesions should only be excised if large (>2cm) or infected. Laser excision is often well tolerated. Plaque control, scaling, and curettage are usually the treatment of choice.
• Facial changes: Melasma (mask of pregnancy), bilateral brown patches on the face, appear in the first trimester in up to 73% of pregnant women.
• Parathyroid hormone: Increased to support fetal skeletal development, resulting in lower serum calcium levels in mothers.
• Cardiovascular changes: Cardiac output and pulse rate rise significantly (30-50% above normal) by the third trimester. Systolic and diastolic blood pressure temporarily drops (10-15 mmHg) in the first trimester but returns to normal in the second. Patients may develop systolic murmurs (transient). Hormone-induced vascular permeability changes can lead to gingivitis and spontaneous gum bleeding in the second and third trimesters. Management includes scaling, curettage, and oral hygiene instructions. Around the third trimester, a larger uterus compresses the inferior vena cava, restricting venous return, potentially causing postural hypotension in the supine position (supine hypotensive syndrome).
• Respiratory changes: Increased respiratory minute volume (up to 40%) in the first trimester due to progesterone leading to respiratory alkalosis. Decreased respiratory lung movement in the third trimester due to enlarged uterus. This may cause significant dyspnea. Increased estrogen levels in pregnancy may lead to upper respiratory tract infections, such as rhinitis and sinusitis.
• Gastrointestinal changes (acid reflux): Progesterone slows intestinal motility and raises intragastric pressure, increasing esophageal reflux, nausea, and vomiting. Dental erosion may occur. Patients in the first trimester need to be monitored for hyperemesis gravidarum (morning sickness). Such patients should not be seen in the morning. Salivary flow decreases (dry mouth) in the first and third trimesters, leading to reduced buffering abilities and increased cariogenic activity. This may cause oral candidiasis. Topical fluoride may be used for patients with dry mouth. Salivary flow may increase (ptyalism) in the second trimester.
• Genitourinary changes: Glomerular filtration rate and plasma flow increase. Urinary bladder distension is limited by the enlarged uterus; this results in frequent micturition (bladder compression). Patients in the second and third trimesters should empty their bladders before dental procedures. Office temperatures should be appropriate (at or above standard room temperature) to prevent cold diuresis or trigger micturition reflex.

Dental Radiography and Pregnancy

• Everyday radiation exposure (background and cosmic): Average American is exposed to 0.62 rads per year. Some Indian and Chinese regions have higher exposures.
• Radiation risks are highest in the first trimester, especially the first 6 weeks. A radiation dose below 25 rads (250 mGy) is unlikely to cause spontaneous abortion. Above 500 mGy (50 rads) in the first trimester may cause congenital fetal abnormalities. After the 16th week of conception, the safety threshold rises to 50-70 rads (<700 mGy).
• A single periapical radiograph delivers ~0.01 millirads. Exposure from 4 bitewings is approximately 0.07 mGy (0.007 rads) and from a panoramic examination ~0.02 mGy (0.02 rads). It is safe to perform radiographs in pregnancy if it is medically necessary. Avoidance of radiographs in the first trimester is preferred. Using shielding (lead aprons) and modern radiographic techniques can minimize risks.

Pregnancy and Dental Drugs

• Analgesics (1): Acetaminophen is generally safe, while aspirin must be avoided in the third trimester due to postpartum hemorrhage risk, and naproxen and ibuprofen may complicate parturition. Other opioid analgesics may cause neonatal respiratory depression.
• Antibiotics and antiprotozoa (2): Amoxicillin, penicillin, cephalosporins, metronidazole, and clindamycin are typically safe. Tetracycline and erythromycin (estolate form) should be avoided as they can cause side effects.
• Local anesthesia and sedatives (3): Lidocaine (with or without epinephrine) and prilocaine are generally safe. Use of mepivacaine and bupivacaine may cause fetal bradycardia. Nitrous oxide should be cautiously monitored and used with above 50 percent oxygen in the 2nd and 3rd trimesters. Prolonged benzodiazepine exposure can result in oral clefts in neonates.
• Antifungal drugs (4): Clotrimazole and nystatin are generally safe. Fluconazole and ketoconazole are best avoided, particularly with caution, in pregnancy.
• Corticosteroids (5): Prednisolone is generally safe.
• Anti-ulcer drugs and peptic/duodenal ulcer prophylaxis (7): Proton pump inhibitors (PPIs; Omeprazole, esomeprazole, and pantoprazole) are typically safe but haven't extensively tested. H2 receptor blockers (ranitidine and famotidine) appear safe. Antacids are typically safe. Misoprostol should be avoided due to spontaneous abortion risks.
• Antihistamines and anti-allergies (8): First-generation antihistamines (chlorpheniramine, hydroxyzine, and promethazine) may be safe. However, second-generation antihistamines (cetirizine, loratidine, and fexofenadine) are usually safe or considered safer choices.

Proposed Treatment Plan

• First Trimester: Educate about oral changes, emphasize strict oral hygiene, limit to periodontal prophylaxis and emergencies
• Second Trimester: Oral hygiene, plaque control, scaling, polishing, curettage (if needed), active oral disease control, elective dental care is safe
• Third Trimester: Oral hygiene, plaque control, scaling, polishing, curettage (if needed), avoid elective dental care during the second half.