Entyvio (vedolizumab) does not appear to increase the risk of birth defects, pregnancy loss, or serious infant infections based on the evidence available so far. Multiple pregnancy registries, cohort studies, and a recent dedicated pregnancy exposure registry have found no meaningful differences in outcomes between women who took vedolizumab during pregnancy and those who did not. The data are still more limited than what exists for older biologics like infliximab and adalimumab, but the safety signal has been consistently reassuring, and the drug’s unique mechanism of action gives it a theoretical advantage over other biologics when it comes to fetal exposure.
What the Pregnancy Registries Show
The strongest piece of evidence comes from a dedicated vedolizumab pregnancy exposure registry, which compared birth outcomes in women who took vedolizumab during pregnancy with outcomes in a disease-matched comparator group and a healthy reference group. The registry found no meaningful differences in rates of pregnancy loss, preterm birth, or birth defects between the groups.1PubMed. Birth Outcomes in Women Who Have Taken Vedolizumab in Pregnancy: Results from the Vedolizumab Pregnancy Exposure Registry That finding lines up with data from the PIANO registry, a large prospective U.S. registry tracking IBD medications in pregnancy. Among 66 vedolizumab-exposed pregnancies in PIANO, there was no increased risk of spontaneous abortion, low birth weight, congenital malformations, or neonatal intensive care unit stays.2American Journal of Gastroenterology. Maternal and Neonatal Outcomes in Vedolizumab- and Ustekinumab-Exposed Pregnancies: Results From the PIANO Registry
A European multicenter cohort added more data, reporting on 44 vedolizumab-exposed pregnancies that resulted in 38 live births, five spontaneous abortions, and one medical interruption. Rates of prematurity, miscarriage, congenital malformations, and maternal complications were comparable to a group of pregnancies exposed to ustekinumab, another newer biologic. The investigators reported no negative signal on maternal or neonatal outcomes.3PubMed. Safety of ustekinumab or vedolizumab in pregnant inflammatory bowel disease patients: a multicentre cohort study Animal studies have also shown no evidence of harm to developing offspring after vedolizumab exposure.4PubMed. Safety of New Biologics (Vedolizumab and Ustekinumab) and Small Molecules (Tofacitinib) During Pregnancy: A Review
How Vedolizumab Compares to Anti-TNF Biologics
Anti-TNF medications like infliximab and adalimumab have been used in pregnancy for well over a decade and carry the most robust safety data of any biologic in this setting. When researchers compare vedolizumab head-to-head with those drugs, the picture is mostly reassuring but carries a few nuances worth understanding.
A large database study comparing 398 vedolizumab-exposed pregnancies with 1,592 anti-TNF-exposed pregnancies found that vedolizumab was not associated with increased risks of abortion, caesarean section, stillbirth, preterm birth, serious infections, malignancies, or congenital abnormality in children.5PubMed. Safety of Vedolizumab and Ustekinumab Compared With Anti-TNF in Pregnant Women With Inflammatory Bowel Disease However, a separate systematic review and meta-analysis found a modestly higher risk of preterm delivery with vedolizumab compared to anti-TNF agents, with about a 35 percent relative increase.6PubMed. Pairwise Comparative Safety and Effectiveness of Anti-TNF Blockers, Vedolizumab, and Ustekinumab During Pregnancy: A Systematic Review and Meta-Analysis That same meta-analysis also found vedolizumab users were more likely to have active disease during pregnancy.
This is where interpretation gets tricky. Vedolizumab is often reserved for people who have already failed anti-TNF therapy, meaning the population taking vedolizumab during pregnancy tends to have more refractory, harder-to-control disease. When a group of patients has more severe underlying illness, teasing apart whether worse outcomes are caused by the drug or by the disease itself is difficult. The slightly higher preterm birth rate observed in some studies may reflect the disease burden of the vedolizumab population rather than a drug effect. The PIANO registry data support this interpretation: vedolizumab’s preterm birth rate of about 14 percent was similar to that seen with combination therapy and only moderately higher than the unexposed group’s rate of roughly 10 percent.7American Journal of Gastroenterology. Maternal and Neonatal Outcomes in Vedolizumab- and Ustekinumab-Exposed Pregnancies: Results From the PIANO Registry
Why Vedolizumab Crosses the Placenta Less
One of vedolizumab’s advantages over anti-TNF biologics is that it crosses the placenta at lower levels. Like other monoclonal antibodies, vedolizumab is an IgG molecule, so it does get actively transported across the placenta during the second and third trimesters. But it transfers less efficiently than infliximab or adalimumab. A prospective multicenter study found that the median vedolizumab concentration in cord blood was about two-thirds of the maternal level, with a median infant-to-maternal ratio of 0.66.8PubMed Central. Differences in the placental pharmacokinetics of vedolizumab and ustekinumab during pregnancy in women with inflammatory bowel disease: a prospective multicentre study For comparison, anti-TNF agents like infliximab often reach cord blood levels that are higher than the mother’s levels at delivery, sometimes two to three times higher.
The cord blood levels of vedolizumab correlated strongly with how recently the mother had her last infusion. Women who received their last dose closer to delivery had higher cord blood levels; women with a longer gap between the final infusion and delivery had lower levels.9PubMed Central. Differences in the placental pharmacokinetics of vedolizumab and ustekinumab during pregnancy in women with inflammatory bowel disease: a prospective multicentre study This relationship is one reason some clinicians discuss timing the last dose of vedolizumab before delivery, though guidelines emphasize that this decision should be individualized and weighed against the risk of a disease flare.
How Quickly Babies Clear the Drug
Even when vedolizumab does cross the placenta, babies clear it from their systems faster than they clear anti-TNF agents. The mean time to vedolizumab clearance in infants was about 3.8 months, and no infant had detectable levels of vedolizumab at six months of age.10Journal of Crohn’s and Colitis. Vaccines in Children Exposed to Biological Agents In Utero and/or During Breastfeeding: Are They Effective and Safe? – Section: 4. Vedolizumab A separate review estimated vedolizumab clearance at around 15 weeks, compared with roughly 19 weeks for anti-TNF agents.11PubMed. New drugs for the treatment of IBD during conception, pregnancy, and lactation
The faster clearance matters most when it comes to infant vaccinations, which is where the practical implications for new parents become most concrete.
Infant Vaccinations After In Utero Exposure
The standard concern with any biologic exposure during pregnancy is live vaccines. If a baby still has circulating biologic drug from the mother, a live vaccine could theoretically cause an uncontrolled infection rather than a normal immune response. For anti-TNF agents, guidelines have traditionally recommended delaying live vaccines (particularly the rotavirus vaccine and BCG, where given) until the drug has cleared from the infant’s system, usually around six to seven months of age.
Vedolizumab’s faster clearance and its gut-selective mechanism of action change the risk calculation. In one prospective study, infants exposed to vedolizumab in utero had undetectable drug levels at a median of about 10 to 11 weeks of age. Immunologic assessments were normal in all of these infants despite prior drug exposure. Fifty infants in the study received the live oral rotavirus vaccine series, with the first dose given at a median of 13 weeks of age, and no adverse effects were reported.12PubMed. Live Rotavirus Vaccination Appears Low-risk in Infants Born to Mothers With Inflammatory Bowel Disease on Biologics
This is reassuring, because rotavirus vaccination is ideally given starting at two months of age, and delaying it significantly reduces its effectiveness. The emerging evidence suggests that vedolizumab-exposed infants can safely receive live rotavirus vaccine on a normal schedule, though you should discuss the timing with your baby’s pediatrician, who can check whether the drug has cleared if there is any uncertainty.
Serious Infections in Exposed Infants
Beyond vaccinations, a natural worry is whether babies exposed to vedolizumab in the womb are more vulnerable to infections in general. A study of 255 mother-infant pairs, including 135 vedolizumab-exposed and 120 disease comparators, tracked serious infections during the first year of life. The rate of serious infections was essentially the same in both groups: about 9 to 10 per 100 person-years. The adjusted hazard ratio was 0.94, meaning vedolizumab-exposed infants had no increased risk.13Oxford Academic (Inflammatory Bowel Diseases). Serious Infections in Offspring Exposed in Utero to Vedolizumab Rates of serious infections at birth, four months, and within the first twelve months of life were also comparable across all treatment cohorts in the PIANO registry.14American Journal of Gastroenterology. Maternal and Neonatal Outcomes in Vedolizumab- and Ustekinumab-Exposed Pregnancies: Results From the PIANO Registry
Vedolizumab’s mechanism may explain this. Unlike anti-TNF agents, which suppress a broad arm of the immune system throughout the body, vedolizumab works by blocking a protein that directs immune cells specifically to the gut. It is not a systemic immunosuppressant in the way that infliximab or adalimumab is, so its impact on the developing immune system is expected to be more limited.
Breastfeeding on Vedolizumab
Vedolizumab is detectable in breast milk, but the amounts that reach a nursing infant appear to be very small. A prospective postmarketing lactation study found that vedolizumab was present in about 90 percent of milk samples collected from treated mothers. The milk-to-serum concentration ratio was roughly 0.4 to 2.2 percent, consistent with what is seen with other monoclonal antibodies.15PubMed Central. Vedolizumab Concentrations in Breast Milk: Results from a Prospective, Postmarketing, Milk-Only Lactation Study in Nursing Mothers with Inflammatory Bowel Disease That low ratio is expected because monoclonal antibodies are large proteins that do not easily pass into breast milk. Even what does pass through would then be largely broken down in the infant’s digestive tract before absorption.
The study also reported no adverse findings for breastfed infants. A case report of a patient with ulcerative colitis who continued vedolizumab through pregnancy (carrying twins) and into breastfeeding similarly reported no complications for the infants.16Europe PMC / Dove Press. Vedolizumab Safety During Pregnancy and Lactation in a Patient with Ulcerative Colitis: A Case Report Current European guidelines support continued breastfeeding for women on vedolizumab.17Journal of Crohn’s and Colitis. European Crohn’s and Colitis Guidelines on Sexuality, Fertility, Pregnancy, and Lactation
When the Father Is Taking Vedolizumab
Concerns about medication exposure are not limited to mothers. If the father is on vedolizumab at the time of conception, many couples wonder whether the drug could affect sperm quality or raise the risk of birth defects. The evidence here is thinner but does not raise red flags. A study specifically assessing sperm DNA integrity in men with IBD taking vedolizumab found no impairment. At the time of that publication, 15 pregnancies from vedolizumab-exposed fathers had been reported, with eight live births, two spontaneous abortions, two elective terminations of unknown cause, and three undocumented outcomes.18Gastroenterology. Vedolizumab Does Not Impair Sperm DNA Integrity in Men With Inflammatory Bowel Disease
More broadly, a systematic review and meta-analysis looking at paternal exposure to biologic and immunosuppressive agents across immune-mediated inflammatory diseases found no association between non-TNF-targeting biologic agents (a category that includes vedolizumab) and the risk of major congenital malformations.19PubMed Central. Paternal Exposure to Immunosuppressive and/or Biologic Agents and Birth Outcomes in Patients with Immune-Mediated Inflammatory Diseases Men should not stop vedolizumab because they are trying to conceive.
What the Guidelines Actually Recommend
European Crohn’s and Colitis Organisation (ECCO) guidelines state that vedolizumab may be considered to treat a flare during pregnancy and can be combined with a faster-acting agent like corticosteroids when needed. For women already in remission on vedolizumab, the guidelines recommend an individualized decision about whether to continue treatment, weighing the risk of relapse against the limited long-term data on fetal exposure.20Journal of Crohn’s and Colitis. European Crohn’s and Colitis Guidelines on Sexuality, Fertility, Pregnancy, and Lactation
The word “individualized” is doing a lot of work in that recommendation. In practice, most gastroenterologists favor continuing vedolizumab through pregnancy if it is keeping your disease under control. Stopping a biologic that is working well creates a real and well-documented risk of disease flare, and active IBD during pregnancy is clearly associated with worse outcomes: preterm birth, low birth weight, and increased risk of pregnancy complications. The meta-analysis that found higher rates of active disease in vedolizumab users during pregnancy also found a higher preterm delivery rate in that group, underscoring that disease activity itself may be the culprit behind adverse outcomes rather than the medication.21PubMed. Pairwise Comparative Safety and Effectiveness of Anti-TNF Blockers, Vedolizumab, and Ustekinumab During Pregnancy: A Systematic Review and Meta-Analysis
The Fear That Causes More Harm Than the Drug
One of the most persistent challenges around IBD medications in pregnancy is not the drugs themselves but the anxiety surrounding them. A survey of women with IBD found that 84 percent reported concerns about the effect of their medications on pregnancy, and free-text responses indicated this worry was greater than any concern about the effect of a disease flare itself.22Journal of Crohn’s and Colitis. Pregnancy and IBD treatment: This challenging interplay from a patients’ perspective That fear frequently leads women to stop or reduce their medication without medical guidance, often triggering a flare at the worst possible time.
The evidence consistently points in one direction: uncontrolled inflammation during pregnancy carries clear risks for both mother and baby, while vedolizumab exposure has not been linked to increased birth defects, serious infant infections, or long-term harm. If vedolizumab is keeping your Crohn’s disease or ulcerative colitis in remission, the safest course is almost always to continue it. That conversation with your gastroenterologist should happen before conception if possible, but the data support continuing treatment even when the pregnancy is unplanned.
Timing the Last Dose Before Delivery
Some clinicians discuss whether to adjust the timing of the final vedolizumab infusion before the due date, aiming to reduce drug levels in the newborn at birth. Because cord blood vedolizumab levels correlate with how recently the mother received her last infusion, a longer gap between the final dose and delivery means lower infant levels at birth.23PubMed Central. Differences in the placental pharmacokinetics of vedolizumab and ustekinumab during pregnancy in women with inflammatory bowel disease: a prospective multicentre study In practical terms, if a woman’s due date falls midway through her dosing cycle, some doctors will schedule the last infusion earlier in the third trimester to allow more clearance time.
But this is a balancing act. Spacing out infusions too aggressively risks losing disease control in the final weeks of pregnancy, a period when flares are particularly unwelcome because of the physical demands of labor and recovery. The infant infection data showing no increased risk in vedolizumab-exposed babies suggests that minimizing cord blood levels, while reasonable in theory, may not be clinically necessary for most patients. A targeted review of vedolizumab safety in pregnancy reported 167 live births among 213 documented vedolizumab-exposed pregnancies with known outcomes, along with 35 miscarriages and 1 stillbirth, rates that fall within the range expected in the general population and in IBD populations regardless of treatment.24PubMed Central. Safety of vedolizumab in the treatment of pregnant women with inflammatory bowel disease: a targeted literature review
How Vedolizumab’s Gut Selectivity Changes the Equation
Vedolizumab is sometimes described as a “gut-selective” biologic because it blocks α4β7 integrin, a molecule that guides immune cells specifically to intestinal tissue. Unlike anti-TNF agents, which neutralize a signaling molecule (TNF-α) active throughout the entire body, vedolizumab’s primary immunosuppressive effect is concentrated in the gastrointestinal tract. This selectivity is the reason vedolizumab carries a lower risk of systemic infections in adult patients compared with anti-TNF therapy, and it likely explains why in utero exposure does not appear to compromise the infant’s immune defenses at birth or during the first year of life.
The practical takeaway is that vedolizumab occupies a somewhat unusual position among IBD biologics in pregnancy. It has less data than the anti-TNF agents, which have been studied in thousands of pregnancies, but its mechanism of action gives it a theoretical safety margin that the data so far appear to confirm. For women who are well controlled on vedolizumab and whose gastroenterologist is comfortable continuing it, the accumulating evidence provides genuine reassurance. If you are planning a pregnancy or have just learned you are pregnant while taking Entyvio, a preconception or early-pregnancy conversation with your gastroenterologist can help you weigh the specific factors in your case, including disease severity, treatment history, and how long you have been in remission.