After adjusting the monitor on my patient's stomach so I could hear the baby's heartbeat, I pulled up her chart to see her history.

"I see here it says you had your first child…[pause]…nine months ago?" I asked, not being able to hide the surprise from my voice.

"Yes, that's right," my patient said without hesitation. "I planned it that way. I wanted them to be really close in age."

And close in age they were. According to the patient's dates, she got pregnant again almost the moment she left the hospital. It was kind of impressive, actually.

As a labor and delivery nurse, I saw the same mothers coming back almost exactly nine months later more often than you would think.

So exactly how easy it is to get pregnant right after you have a baby? Let’s find out.

The Return of Fertility

How soon you will get pregnant again depends if you will be breast-feeding or not.

Breast-feeding and the hormones that go along with milk production can suppress a woman's ovulation from returning.

If you're not breast-feeding, ovulation usually doesn't return until at least six weeks postpartum for most women. One review published in the journal Obstetrics and Gynecology found, on average, that ovulation returned for nonlactating women on day 74 postpartum.

But the range of when ovulation occurred and if that ovulation was functional ovulation (meaning the woman could actually get pregnant with the ovulation) varied greatly.

A woman will ovulate before her period returns. Because of this, she might miss signs that she is ovulating if she is trying to avoid pregnancy.

This is how some women can get pregnant without even having their periods back between pregnancies.

The Breast-Feeding Factor

Breast-feeding, in theory, is supposed to prolong the return of a woman's cycle, especially in the first six months postpartum.

But exactly how long breast-feeding can delay the return of fertility varies. It depends how often a baby nurses, environmental stressors, and how long the baby will sleep for stretches at a time.

Every woman is different. For example, I never got my period back until eight or nine months postpartum. But one of my friends who also exclusively breast-fed got her period at only six weeks postpartum.

Although doctors have confirmed that the delay of a woman's cycle with breast-feeding can be 98 percent effective, it's important to remember that its effectiveness only occurs if your baby is:

  • under 6 months old
  • exclusively breast-fed — no bottles, pacifiers, or other food
  • nursing on demand
  • still nursing at night
  • nursing at least six times a day
  • nursing at least 60 minutes a day

Keep in mind that any fluctuation in the nursing routine, like if your baby sleeps through the night, can cause your cycle to return, too. To be safe, don’t rely on exclusive breast-feeding as effective birth control past nine weeks.

Getting Pregnant Again

In general, most women won't start ovulating right away after having a baby, but the return of the menstrual cycle ranges widely for women.

Every woman's personal cycle is different and factors like weight, stress, smoking, breast-feeding, diet, and contraceptive choices will affect the return of fertility.

If you're planning on avoiding pregnancy, you will want to talk to your doctor about family planning options, especially if you're breast-feeding and aren't sure when your cycle will return.

Takeaways

Ideally, mothers should wait at least 12 months between pregnancies, according to the U.S. Department of Health and Human Services.

A longer gap of at least 2.5 years between pregnancies might be beneficial to prevent premature birth and delivery at a low birth weight.

Intervals that are too short (under 18 months) and too long (over 60 months) have been associated with negative outcomes for both mom and baby.

Chaunie Brusie