Whether you (or someone you know) planned to have children close together, or are having a sweet surprise sooner than expected, there’s a lot to know about short interval pregnancies, formerly known as " having Irish twins", and its safety.
For starters, the term “Irish twins” is out. As explained by VeryWellFamily.com, “The phrase ‘Irish twins’ originated in the late nineteenth century as a derogatory term associated with Irish immigration to the United States. Back then, when the phrase was used, the person was stereotyping the Irish and implying that they were uneducated, poor, and lacked self-control.”
Alexandria Richards, M.D., OB-GYN at Baylor Scott & White Health in College Station, Texas, tells Romper that closely spaced pregnancies are actually called short interval pregnancies, or SIPs. She says it’s important to monitor the mom-to-be for a few specific concerns when she has two pregnancies within the same year.
“Most women, after they deliver a baby, are going to be slightly anemic, so if they got pregnant again in that first year, they have an even higher risk of being anemic,” she says. “We check that routinely on labs. The thing that doesn’t show up on lab work is a folate deficiency. The first baby is going to use up mom’s folate stores, so if she’s wanting a short interval pregnancy, she definitely needs to continue her folate supplement and prenatal vitamin.”
Victor R. Klein, M.D., board-certified OB-GYN at Northwell Health and vice chairman of Obstetrics & Gynecology at North Shore University Hospital, tells Romper that C-section moms who get pregnant within a year of their birth may have an increased risk of uterine rupture (just because that scar may still be healing). Klein specializes in high-risk pregnancies.
“If a woman had a previous C-section and she has a scar in the uterus, there’s controversy over how much she should wait before the next pregnancy. We don’t want people to get pregnant right away to make sure their scar heals properly. My recommendation is somewhere between six months and a year based on your health. If a woman is 40, maybe she doesn’t want to wait a year, so I might work with her on that,” he says.
Richards’ main concern actually revolves just as much around mental health as physical health. One baby means plenty to do already, but adding a pregnancy and second baby on top can be overwhelming.
“The other thing to think about with SIP is depression and anxiety. Postpartum depression does not go away with another pregnancy, so sometimes you can see an increased risk of that because having a newborn and being nauseous and going through all that again can be incredibly stressful as well,” Richards says.
When it comes to the second baby, there are some slight risks to their health, too. But generally speaking, they do just fine. Richards says there's not a lot of great data, but the little data there is shows a higher chance of spina bifida because of the folate deficiency. But again, it's a very small amount of data, so there's not much to go on. “They also have a higher risk of preterm labor and being smaller because they’re preterm, and maybe a smaller risk of placental abruption. All that is a small increase on top of the standard risk. Most babies will do OK as long as mama does OK," she adds.
“The risk to the newborn is a preterm birth, so SIPs put that second pregnancy at risk. The recommendation, if at all possible, is to wait 18 months between pregnancies,” adds Adriann Combs, DNP, board-certified neonatal nurse practitioner and clinical director of Obstetrics and Gynecology at Northwell Health, in an interview with Romper.
If you’re an SIP mama, Richards says you may have more frequent ultrasounds to monitor your baby’s growth, and your OB-GYN may put you on an iron supplement in addition to your prenatal vitamin to keep anemia at bay. She also tries to do a depression screening sooner than usual to be sure her patients are feeling well.
Klein adds that, for most women, having a short interval pregnancy goes well for the majority of low-risk patients, though it’s best to get clearance from your doctor or midwife if you’re planning an SIP. He recommends thinking about birth control after birth to prevent additional pregnancies if you’re not ready to add another member to the family.
“If you’re not interested in getting pregnant, use birth control or natural family planning and don’t use breastfeeding as your sole method, because it’s not effective. If you deliver today and you’re nursing your baby, it may be two months, six weeks, three months, but you can become fertile again despite the fact that you’re nursing.”
If you or someone you know is seeking help for mental health concerns, visit the National Alliance on Mental Illness (NAMI) website, or call 1-800-950-NAMI(6264). For confidential treatment referrals, visit the Substance Abuse and Mental Health Services Administration (SAMHSA) website, or call the National Helpline at 1-800-662-HELP(4357). In an emergency, contact the National Suicide Prevention Lifeline at 1-800-273-TALK(8255) or call 911.
Alexandria Richards, M.D., OB-GYN at Baylor Scott & White Health in College Station, Texas
Victor R. Klein, M.D., board-certified OB-GYN at Northwell Health and vice chairman of Obstetrics & Gynecology at North Shore University Hospital
Adriann Combs, DNP, board-certified neonatal nurse practitioner and clinical director of Obstetrics and Gynecology at Northwell Health
Motomura K, Ganchimeg T, Nagata C, Ota E, Vogel J, Betran A, Torloni M, Javartne K, Jwa S, Mittal S, Recidoro Z, Matsumoto K, Fujieda M, Nafiou I, Yunis K, Qureshi Z, Souza J, Mori R. (2017) Incidence and outcomes of uterine rupture among women with prior caesarean section. Scientific Reports, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5345021/.