I got pregnant at 48 and then again at 50. People didn't think it was a great idea, but as a fertility nurse, I want others to know it's OK.

• Jennifer Michalke is 51 years old and has two toddlers.
• She used donor eggs to conceive both her daughters.

This as-told-to essay is based on a conversation with Jennifer Michalke. It has been edited for length and clarity.

During my 20s, I was going out and having fun. When I hit my 30s, I knew I wanted a family but didn't have a partner, so I focused on my work as a nurse, first in obstetrics and then at New York University's fertility clinic. By the time I met my husband and married at 45, most people assumed I wouldn't have children.

Still, I wanted to have a family. Because of my professional background, I knew it was a possibility. The first step was to convince my husband. He has two grown children, one biological and one adopted. He'd long ago had a vasectomy and wasn't sure he wanted to start over again.

The day he said he was willing to talk to a doctor about a reversal, I booked an appointment immediately. We talked to a fertility specialist at NYU, where I used to work. It was far from our home in Vermont, but I knew firsthand that the clinic provided top-notch care. I figured I would have one child, and I wanted the best odds.

I used donor eggs to have my daughters

In my late 40s, I knew I couldn't get pregnant using my own eggs, but I was comfortable with donor eggs. I grew up proud of my Irish heritage, so I chose a donor who shared that. The process had some silver linings. My family has many health concerns, including mental illness, diabetes, and kidney disease. Using donor eggs, I could avoid those and give my children a better chance at characteristics I wish I had, like taller stature and blue eyes.

It took three donors and three rounds of in vitro fertilization to get pregnant. During that time, we heard many opinions. People asked why we didn't adopt — it's not that easy, plus I wanted to be pregnant and raise an infant. Others said I was selfish for having a child later in life because we might not be around long enough for our kid, but when is tomorrow ever guaranteed?

Throughout it, I knew that my husband and I were making the right choice for our family.

My first pregnancy, at 48, was very complicated

My pregnancy with Sadie, who is now 3, was very difficult. Some of it was age-related, and some of it wasn't. I had a subchorionic hemorrhage, or bleeding behind the placenta. It's more common in people who have undergone IVF, regardless of age. I bled heavily at six weeks and every day between 14 and 19 weeks. Doctors said there was nothing we could do except see if the pregnancy stuck. I was terrified.

The complications continued. I developed gestational diabetes, which becomes more common with age. I had a three-day induction and then needed a cesarean; both long inductions and C-sections are more common in moms over 40.

Every time I went to the doctor, I saw the words "geriatric mother" stamped across the top of my file. I wished they could use something a bit kinder, even if it was "advanced maternal age."

In public, I got some strange looks. Yet a lot of my pregnancy was normal.

My pregnancy at 50 was much easier

When Sadie was 1, we got a letter from our fertility clinic asking whether we wanted to pay the annual fee to store our five remaining embryos. I didn't want to pay, but I just couldn't bring myself to let them be discarded.

Age played a role in our decision to have a second child together. Sadie will have aging parents at a relatively young age. I didn't want her to have to deal with that alone.

My husband agreed to one last IVF cycle. That was fine because the NYU clinic also had a policy of not implanting embryos in people 50 or older. I had enough time for just one cycle before my birthday. Luckily, it took.

My pregnancy with Alice was so different. It was healthy and relaxed. My providers had me come in more often because of my age and my complicated pregnancy with Sadie. I wasn't labeled geriatric, at least that I could see. Throughout, I felt well cared for.

I want others to know it's OK to have kids later

Today, my husband and I are 53 and 51, respectively, while the girls are 3 and 1. Most of our friends are waiting for grandchildren. Sometimes they invite us out, and we have to remind them we still have toddlers.

I've also made a new set of friends who have children the same age. I dye my hair a little more often to hide the grays, but when we're at PTA sales or playgroups, my age isn't a factor. It comes up only if I mention a band or cultural reference that my friends don't know. I could be a mother to some of them, but we're bonded because we share this part of life.

It's important to think about your biological clock, but it's not like an alarm goes off and, all of a sudden, it's too late to have a family. Financially and emotionally, I'm a better parent in my 50s than I would have been in my 20s. True, my body didn't bounce back from pregnancies, and I'll have to work a bit longer before retiring. All of that was worth it for the family I dreamed of.