Human Papillomavirus (HPV) is a widespread viral infection, recognized as the most common sexually transmitted infection globally. While many HPV infections are asymptomatic and resolve on their own, certain types can lead to health issues, including genital warts and specific cancers. For expectant parents, a significant concern often arises regarding the possibility of transmitting HPV from a mother to her infant during the birthing process.
How HPV Can Be Passed to Infants
HPV transmission from a mother to her infant is possible, though it is considered a rare event. This vertical transmission primarily occurs during a vaginal birth, as the infant passes through the birth canal and comes into contact with HPV-infected cells or lesions in the mother’s genital tract.
While some studies have reported varying rates of HPV detection in newborns from HPV-positive mothers, with some indicating around 7% or 11% of newborns testing positive for the virus at birth, other research suggests that many of these early detections may represent temporary contamination rather than persistent infection. The pooled perinatal transmission rate in some analyses has been estimated at approximately 25%, but other findings show a lower pooled transmission rate of around 6.5%.
Factors that might influence this rare transmission include the presence of active genital warts in the mother at the time of delivery or a high viral load of HPV in the cervicovaginal area. Some studies have explored whether the duration of membrane rupture before delivery influences transmission rates, with longer durations potentially increasing the chance of exposure. Even with these factors, the vast majority of pregnant individuals with HPV do not transmit the virus to their babies. Research suggests that when HPV DNA is detected in newborns, it often clears on its own without causing long-term problems, with one study finding no persistent infections beyond six months in newborns.
Potential Health Effects in Infants
Should HPV transmission from mother to infant occur, the most significant, albeit extremely rare, health effect is Recurrent Respiratory Papillomatosis (RRP). This condition involves the growth of benign, wart-like tumors, called papillomas, within the respiratory tract, most commonly in the larynx or voice box. RRP is typically caused by specific HPV types, primarily HPV 6 and HPV 11, which are also responsible for most genital warts. These growths can interfere with normal breathing and voice production.
Symptoms of RRP in infants often include a persistent hoarse cry or voice, chronic cough, and noisy breathing, known as stridor. As the papillomas grow, they can obstruct the airway, leading to more severe breathing difficulties. While RRP is not cancerous, its location in the airway means it can be serious and may necessitate repeated surgical procedures to remove the growths and maintain a clear airway. Despite the need for ongoing management, RRP is treatable, though it can be a chronic condition that requires long-term monitoring and intervention. The occurrence of RRP in children is exceedingly rare, with estimates ranging from two or fewer cases per 100,000 children under 18.
Managing HPV During Pregnancy
Routine HPV screening, often conducted as part of a Pap test, continues during pregnancy. If abnormal results are found, healthcare providers typically manage them cautiously. Abnormal Pap test results or the presence of HPV during pregnancy often lead to watchful waiting, with further evaluation such as a colposcopy being performed if indicated. However, biopsies and treatments for cervical changes are usually deferred until after delivery unless there is a suspicion of cancer. This approach minimizes potential risks to the pregnancy while allowing for close monitoring.
A common question among pregnant individuals with HPV is whether a Cesarean section (C-section) is necessary to prevent transmission to the baby. Healthcare guidelines generally do not recommend C-sections solely to prevent HPV transmission. The risk of transmission is low, and the risks associated with major surgery typically outweigh the potential benefits for HPV prevention. A C-section might only be considered in extremely rare circumstances, such as when large genital warts obstruct the birth canal or could cause significant bleeding during a vaginal delivery.
Discussing any concerns or the presence of active lesions with a healthcare provider is important for personalized guidance. While HPV vaccination is not recommended during pregnancy, it is a primary prevention method that can be completed before conception. If vaccination inadvertently occurs during pregnancy, current data do not suggest adverse outcomes for the fetus, but further doses are typically delayed until after delivery. This preventive measure can reduce the risk of HPV infection and its associated complications before pregnancy begins.