Bacterial Vaginosis (BV) During Pregnancy: Causes, Symptoms And Treatment

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Bacterial vaginosis (BV) in pregnancy is a common vaginal infection. It happens due to the domination of unhealthy bacteria in the vagina. BV leads to pregnancy complications and other perinatal outcomes such as low birth weight or preterm birth. (1).

The Centers for Disease Control and Prevention (CDC) conducted a retrospective cohort study and established that around 30% of all pregnant women in the US (about 29.2 million) are affected by BV. In several instances, most women are not aware of the condition until diagnosed (2).

Read the post to learn more about the causes, signs, symptoms, diagnosis, and treatment of BV in pregnancy.

What Causes Bacterial Vaginosis In Pregnancy?

BV is caused by the imbalance of lactobacilli in the vaginal microbiome (3). Lactobacilli are responsible for maintaining an acidic environment in the vagina, which prevents the overgrowth of other bacteria and clinical indications of intrauterine infection. The risk of acquiring BV is higher in asymptomatic women who

  • Have a sexually transmitted disease
  • Have an implant or intrauterine device (IUD)
  • Have multiple sexual partners
  • Have sex with women

What Are The Signs And Symptoms Of Bacterial Vaginosis?

Most women with BV may not experience noticeable symptoms. Nevertheless, if you suspect you have BV, check for the following symptoms and contact your healthcare professional (4):

  • Thin greyish vaginal discharge
  • Fishy odor from the vaginal secretions, especially after sex
  • A burning sensation while urinating
  • Itching and discomfort around the vagina

If you suspect that you may have BV, contact your gynecologist and discuss your observations with them. It is important to refrain from self-medication without consulting a doctor, as some medicines might harm the developing fetus.

How Is Bacterial Vaginosis Diagnosed?

BV is diagnosed and screened in pregnant women based on the healthcare provider’s discretion and available facilities. However, some common diagnostic procedures are (5)

  • Microbiological testing of vaginal fluid swab/culture
  • Gram stain analysis of morphotypes

How Is Bacterial Vaginosis Treated During Pregnancy?

No OTC medicines are available for treating BV. Therefore, doctors mostly prescribe antibiotic treatment, such as metronidazole or oral clindamycin. Since antibiotics also affect the good bacteria in the vagina, they are not prescribed unless necessary. Other treatment options include vaginal probiotics or ointments containing vaginal clindamycin to help reduce the symptoms and adverse effects of BV (1) (6).

What Are The Complications Of Bacterial Vaginosis During Pregnancy?

BV in pregnant women may increase the risk for the following adverse pregnancy outcomes if left untreated (1) (7):

  • Fetal and maternal morbidity
  • Abortion
  • Preterm delivery
  • Spontaneous preterm birth
  • Premature rupture of membranes causing peripartal infections
  • Amniotic fluid infection
  • Postpartum endometritis
  • Genitourinary infections
  • Pelvic inflammatory disease
  • Wound infection or genital tract infection post cesarean delivery
  • Low infant birth weight

Can Bacterial Vaginosis Resolve By Itself During Pregnancy?

BV is usually a mild condition that resolves by itself in a few days. However, if the infection persists, it may harm the mother and the baby. Hence, consult your doctor beforehand to prevent future complications.

How Can You Reduce Your Risk For Bacterial Vaginosis?

Taking measures to increase the growth and concentration of lactobacillus bacteria is the first step to help reduce your risk of acquiring BV in pregnancy. Clinical trials have shown that adding probiotics to your diet can help in this regard (8).

Here are some other preventative measures that may reduce the risk of contracting BV (5) (9)

  • Avoid unprotected sex with multiple partners.
  • Avoid douching (washing the inside of the vagina).
  • Wear cotton underwear to help absorb moisture.
  • Avoid vaginal contact with objects that have come into contact with your anus.

BV is a common genital tract infection in women of reproductive age. It is usually self-limiting and without visible symptoms. However, if the infection persists, doctors prescribe antibiotic treatment. If you are pregnant and contract BV, consult your doctor to help prevent adverse pregnancy outcomes and complications for you and your baby.


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Sanjana Bhattacharjee

Sanjana did her post graduation in Applied Microbiology from Vellore Institute of Technology, India. Her interest in science and health, combined with her passion to write made her convert from a scientist to a writer. She believes her role at MomJunction combines the best of both worlds as she writes health-based content based on scientific evidence. Sanjana is trained in classical... more