Can my sister with NMSOD breastfeed or have more kids?

Question

Hello doctor,

My 31-year-old sister was diagnosed with NMOSD about six months ago after she lost vision in her right eye during her third trimester of pregnancy. She had given birth to a healthy baby boy, but three weeks later started having terrible back pain, and then her legs went numb and weak. The neurologist did an MRI and found lesions in her spinal cord extending over four vertebral segments, and she tested positive for aquaporin-4 antibodies.

They started her on Rituximab infusions, but she is terrified about breastfeeding because she does not know if the medication will hurt the baby. Her vision came back mostly, but she still has a blind spot in the center of her right eye. The worst part is that she had another flare last month with bladder problems and cannot control when she needs to pee, which is so embarrassing for her.

She is on Baclofen for muscle spasms and gabapentin for nerve pain, but still struggles to walk without holding onto things. Her husband travels for work a lot, and I am worried about her taking care of the baby alone when she can barely stand up some days.

Is NMOSD going to get worse with each pregnancy?
Can she have more kids safely, or will that trigger more attacks?

Please help.

Thank you.

Answer 1

Hello,

Welcome to icliniq.com.

I have read your query and can understand your concern.

NMOSD (neuromyelitis optica spectrum disorder) is an autoimmune disease where the immune system attacks the optic nerves and spinal cord, causing:

Vision loss (optic neuritis).
Weakness or numbness in the limbs.
Bladder or bowel problems.

It is different from multiple sclerosis (MS) and often more severe during relapses, but modern treatments like Rituximab can control it very well if given regularly.

Breastfeeding while on Rituximab is a very common concern. Here is what is known from medical research and guidelines:

Rituximab is a large antibody molecule (IgG1) that passes into breast milk in extremely small amounts.
Studies have shown almost no detectable Rituximab in babies’ blood and no immune problems or infections in infants whose mothers breastfed while on it.

Most neurology and lactation experts consider Rituximab probably safe for breastfeeding, especially if the baby is full-term and healthy. The mother waits one to two weeks after infusion before resuming breastfeeding (to minimize exposure). So yes, she can likely breastfeed safely, but she should confirm this with her neurologist and pediatrician, since each case may differ slightly.

Now, why did she have flares after delivery?

After childbirth, hormone levels drop sharply, and the immune system rebounds; this often triggers autoimmune flares in conditions like NMOSD (neuromyelitis optica spectrum disorder) or MS (multiple sclerosis). This is likely what caused her postpartum spinal cord attack and bladder symptoms.

For fear that she can, she has more children?

It is understandable to be scared, but the truth is pregnancy itself does not make NMOSD (neuromyelitis optica spectrum disorder) worse; relapses are more common in the three to six months after delivery. With good pre-pregnancy planning and treatment, many women with NMOSD have healthy pregnancies and babies.

Key precautions before another pregnancy:

1. Stay relapse-free for at least six to 12 months before trying to conceive.

2. Coordinate care between a neurologist and a high-risk obstetrician.

3. Restart preventive therapy (like Rituximab) soon after delivery to prevent postpartum relapses

4. Avoid stopping medications abruptly during pregnancy; the doctor will guide the timing of doses safely.

So yes, she can have more children, but it should be carefully planned under medical supervision.

For the bladder and mobility issues, these are unfortunately common after spinal cord attacks in NMOSD, but some treatments can help:

By managing bladder control. A urologist can assess for a neurogenic bladder. Medications (like Oxybutynin or Mirabegron) or intermittent self-catheterization can help prevent leakage and infections.
Also, by improving mobility and reducing muscle stiffness. Physiotherapy and regular stretching alongside baclofen can improve walking balance. Some patients benefit from physical rehab programs designed for spinal cord recovery.

I hope this answers your query.

Please let me know if I can assist you further.

Thank you.