Pregnancy spacing is an essential part of family planning. Understand the importance of pregnancy spacing and what factors to consider before you conceive again.

By Mayo Clinic Staff

Considering having another child? Pregnancy spacing can affect more than how close your children are in age. It can also have an impact on your health and your baby's health. Find out what you need to know about family planning and timing pregnancies.

Whether you're thinking about getting pregnant for the first time or you already have children, it's important to think about family planning and your reproductive goals. Knowing whether you do or don't want to have children in the next few years can help you and your partner prepare for conception or choose appropriate contraception.

After your first child is born, family planning takes on new meaning. Having another child will change your family's lives. Are you and your partner ready to take care of a newborn again? How will your other child or children react to sharing your attention with a new baby?

It's also important to consider the timing of your pregnancies. While you and your partner might have preferences about how close in age you'd like your children to be, some research shows that spacing pregnancies too close together or too far apart can pose health risks for both mother and baby.

Limited research suggests that a pregnancy within 12 months of giving birth is associated with an increased risk of:

  • The placenta partially or completely peeling away from the inner wall of the uterus before delivery (placental abruption)
  • The placenta attaching to the lower part of the uterine wall, partially or totally covering the cervix (placenta previa), in women who had a first birth by C-section
  • Autism in second-born children

Research also suggests an increased risk of uterine rupture in women who attempt vaginal birth after cesarean (VBAC) less than 18 months after a previous delivery.

In addition, a pregnancy within 18 months of giving birth is associated with an increased risk of:

  • Low birth weight
  • Small size for gestational age
  • Preterm birth

Some experts believe that closely spaced pregnancies don't give a mother enough time to recover from the physical stress of one pregnancy before moving on to the next. For example, pregnancy and breast-feeding can deplete your stores of essential nutrients, such as iron and folate. If you become pregnant before replacing those stores, it could affect your health or your baby's health. Inflammation of the genital tract that develops during pregnancy and doesn't completely heal before the next pregnancy could also play a role.

However, it's also possible that behavioral risk factors, such as failure to use health care services, unplanned pregnancies, stress and socio-economic disadvantage, are more common in women who have closely spaced pregnancies. These risk factors — rather than the short interval itself — might explain the link between closely spaced pregnancies and health problems for mothers and babies.

Research suggests that long intervals between pregnancies also pose concerns for mothers and babies. A pregnancy five years or more after giving birth is associated with an increased risk of:

  • High blood pressure and excess protein in your urine after 20 weeks of pregnancy (preeclampsia)
  • Preterm birth
  • Low birth weight
  • Small size for gestational age

It's not clear why long pregnancy intervals are linked to health problems for mothers and babies. Some experts believe that pregnancy improves uterine capacity to promote fetal growth and support, but that over time these beneficial physiological changes disappear. It's also possible that unmeasured factors, such as maternal illnesses, might play a role.

To reduce the risk of pregnancy complications and other health problems, limited research suggests waiting at least 18 to 24 months but less than five years after a live birth before attempting your next pregnancy. However, further research is needed to determine whether the effects of birth spacing on maternal and fetal health differ between developed and developing nations.

Choosing when to have another baby is a personal decision. When planning your next pregnancy, you and your partner might consider various factors in addition to the health risks and benefits, including your health, age, fertility, relationship, how many children you have, how many children you hope to have, access to health care, child-rearing support, and social and economic circumstances.

Until you make a decision about when to have another child, be sure to use a reliable method of birth control — even if you're breast-feeding. Once you feel ready to get pregnant again, ask your health care provider for guidance.

Every child — and family — is unique. However, research suggests that closely spaced pregnancies can affect children. For example, children who are less than two years apart might experience more conflict than do children who have greater age differences. Spacing siblings more than two years apart also might mean better reading and math scores for the older children. This could be a result of parents spending more time with the older children before having a new baby.

There's no perfect time to have another baby. And, even with careful planning, you can't always control when conception happens. However, understanding the risks and benefits associated with timing your pregnancies too close together or too far apart can help you make an informed decision about when to grow your family.

Apr. 15, 2014