It is very common for pregnant women to experience some type of vaginal discharge. This is mainly due to elevated levels of the pregnancy hormones like estrogen, as well as extra blood flow to the vagina and genital region. The vaginal discharge differs in appearance based on its consistency and color, and can be attributed to a multitude of physiological or pathological reasons. White or light yellow discharge with an egg white consistency is usually considered normal. However, it is imperative to mention that yellow discharge during pregnancy with foul smell usually indicates an infection or disease that should be addressed on emergent basis.

Causes of Yellow Discharge During Pregnancy

Estrogen Dominance

Estrogen is a naturally occurring female hormone that is produced within the fat cells, adrenal glands and ovaries. It is involved in the maintenance and development of female sexual characteristics. It can also serve as a source of distress in pregnant women. Elevated estrogen levels lead to excessive vaginal discharge. It is no surprise that the estrogen level shoots up in pregnancy as it provokes a great deal of hormonal imbalance. Other factors that may cause drastic increase in the estrogen levels include stress, increased body fat, diet poor in fiber and compromised immune system. All these factors may leads to excessive yellow discharge pregnancy symptom.

Yeast Infections

Pregnant women are much more prone to develop yeast infections during the second trimester of pregnancy, thus they are regarded as one of the characteristic signs of gestation. These infections are caused by Candida albicans and may manifest as the following signs: thick, white discharge with foul odor, swollen or red vulva, and vaginal itching. The color of mucus differs in each woman and may vary from dark to light yellow. It is not yet known why yeast infections occur in pregnant women, but some experts suggests that hormonal imbalance in pregnancy can alters the pH of vagina, thereby promoting the yeast growth.

Bacterial Vaginosis

It is characterized by the imbalance between bad and good bacteria that are a part of the vaginal flora. Main causes of bacterial vaginosis include douching or having multiple sex partners. BV is distinguished by the symptom of excess, thick, yellow-green discharge with foul smell. Other symptoms include occasional spotting, swollen vulva and itching. Many studies suggest that BV during pregnancy may put women at risk ofpost-pregnancy uterine infection, giving birth to a baby with low weight, premature membrane rupture and preterm birth. 

Sexually Transmitted Diseases

Sexually transmitted diseases, also known as STDs may also cause yellow discharge during pregnancy. The two major STDs that contribute to smelly, discolored, excessive and thick vaginal discharge include:

• Chlamydia: In the US, Chlamydia trachomatis is the most common STD. If it occurs during pregnancy then it is marked by yellow discharge and the color keeps becoming darker with time. The discharge associated with this STD has a sour smell. Swelling and itching of the labia may also be present.
• Gonorrhea: This infection often results from having unprotected intercourse leading to symptoms that cause pain or discomfort. It is characterized by the yellow-orange or yellow-brown discharge particularly in conjunction with foul smell, bleeding (even in between the periods), swollen vulva, burning sensation while urinating, spotting after having sex and pelvic pain. In case of contracted gonorrhea, seek immediate medical help to prevent ectopic pregnancy i.e. development of the fertilized egg outside the uterus. 
• Trichomoniasis. It is a matter of grave concern if the discharge turns green or yellow with a foul smell and thick consistency. It may indicate trichomoniasis, one of the very common STDs. Other trichomoniasis symptoms include itchy, red or irritated vagina or vulva, and feeling of discomfort while having intercourse or urinating.

When to Worry?

There may be other STDs without any characteristic symptoms like burning, irritation or itching. Therefore grey, green or yellow discharge during pregnancy with an unpleasant smell and froth is certainly something to worry about.

How to Deal with Yellow Discharge During Pregnancy

Home Remedies

• If infection is not the cause of the vaginal discharge, then there isn’t much that can be done to get rid of the flow. Panty liners may help a little to absorb the discharge.
• It is suggested to keep the vaginal area nice, clean and healthy, and must be wiped from front to all the way to the back. Cotton underwear is more preferred.
• Avoid deodorant or scented soaps, hygiene sprays, scented toilet paper or pads, bubble bath, nylons and tight pants.
• Avoid douching as it upsets the normal bacterial flora of vagina and increase the chances of having vaginal infection.

Medical Treatments

• It is normal to find yeast in the vaginal flora, so the goal is not to finish the yeast but to reduce the excessive yeast growth within the vagina to restore the healthy balance. The treatment comprises of antifungal agents that may be given in tablet form or as vaginal suppositories or creams. Over-the-counter medicines may also be used. But keeping pregnancy in mind, each and every medicine must be approved by the healthcare professional.
• In case of BV, there’s no over-the-counter medication. Metronidazole may be given as an oral antibiotic or as a topical cream. However, Metronidazole could cause dark colored urine and nausea. Alcohol must be avoided when taking Metronidazole because of potential alcohol intolerance that may promote nausea and vomiting.