What causes abnormal vaginal odor and spotting during pregnancy?

From the Guidelines

Vaginal odor and spotting during pregnancy should be evaluated by a healthcare provider to rule out complications, as bacterial vaginosis or other infections can have adverse pregnancy outcomes, including premature rupture of the membranes, preterm labor, and preterm birth 1. During pregnancy, mild odor changes are common due to increased vaginal discharge (leukorrhea) and hormonal fluctuations. However, strong, fishy, or foul odors may indicate bacterial vaginosis or other infections requiring treatment. Some key points to consider:

• Light spotting, especially in early pregnancy, can be normal and may occur after intercourse or cervical exams.
• For mild odor without other symptoms, maintaining good hygiene with gentle, unscented soap for external washing only is recommended.
• Avoid douching, scented products, and tight synthetic underwear.
• Contact your healthcare provider immediately if you experience spotting with pain, heavy bleeding, strong odors, itching, burning, or unusual discharge color. These symptoms could indicate infections, placental issues, or preterm labor, and proper diagnosis and timely treatment can prevent complications for both mother and baby 1. The benefits of therapy for bacterial vaginosis in pregnant women are to relieve vaginal symptoms and signs of infection, reduce the risk for infectious complications associated with bacterial vaginosis during pregnancy, and reduce the risk for other infections 1. Oral metronidazole or clindamycin are the recommended options for treatment, and a follow-up evaluation should be done one month after completion of treatment to verify that therapy was effective 1.

From the FDA Drug Label

• Irregular vaginal bleeding or spotting • Vaginal yeast infection

The FDA drug label mentions irregular vaginal bleeding or spotting and vaginal yeast infection as possible side effects of Progesterone Capsules.

• Vaginal odor is not directly mentioned in the label, but vaginal yeast infection can cause vaginal odor.
• Spotting is mentioned as a possible side effect. It is recommended to consult a healthcare provider if you experience any unusual symptoms, including vaginal odor or spotting, while taking Progesterone Capsules 2 2.

From the Research

Vaginal Odor and Spotting During Pregnancy

• Vaginal odor and spotting can be caused by various factors, including vaginitis, which is defined as any condition with symptoms of abnormal vaginal discharge, odor, irritation, itching, or burning 3.
• The most common causes of vaginitis are bacterial vaginosis, vulvovaginal candidiasis, and trichomoniasis, with bacterial vaginosis being implicated in 40% to 50% of cases when a cause is identified 3.
• Vaginitis may be uncomfortable, but rarely leads to serious long-term consequences, although pelvic inflammatory disease can lead to serious long-term sequelae, including increased risk for ectopic pregnancy, infertility, and chronic pelvic pain 4.

Diagnosis and Treatment

• Diagnosis of vaginitis is made using a combination of symptoms, physical examination findings, and office-based or laboratory testing 3.
• Bacterial vaginosis is traditionally diagnosed with Amsel criteria, although Gram stain is the diagnostic standard, and newer laboratory tests that detect Gardnerella vaginalis DNA or vaginal fluid sialidase activity have similar sensitivity and specificity to Gram stain 3.
• Treatment of bacterial vaginosis involves oral metronidazole, intravaginal metronidazole, or intravaginal clindamycin, while vulvovaginal candidiasis is treated with oral fluconazole or topical azoles, although only topical azoles are recommended during pregnancy 3.

Importance of Physical Examination

• A physical examination is crucial in diagnosing common causes of vaginitis, as tests from self-obtained vaginal swabs and history alone cannot be used to adequately diagnose bacterial vaginosis, trichomoniasis, and vulvovaginal candidiasis in women presenting with symptomatic vaginal discharge 5.
• The agreement in diagnoses between clinicians examining the patient and performing diagnostic tests versus a clinician with access only to the patient's history and diagnostic findings from self-obtained vaginal swabs was found to be lower for bacterial vaginosis (68.5%) compared to trichomoniasis (90.9%) and vulvovaginal candidiasis (91.9%) 5.