Home deliveries were 10 times more likely to result in an Apgar score of 0 than hospital deliveries, according to a study published online June 21 in the American Journal of Obstetrics & Gynecology.

Further, the research, which includes data on nearly 14 million singleton, full-term births of infants of normal weight from 2007 to 2010, found a nearly 4-fold greater risk for neonatal seizure or serious neurologic dysfunction among home births.

Amos Grünebaum, MD, chief of labor and delivery, New York–Presbyterian/Weill Medical College of Cornell University, New York City, and colleagues used data from the National Center for Health Statistics of the Centers for Disease Control and Prevention to assess deliveries by both physicians and midwives in hospitals, freestanding birth centers, and homes. All of the infants in the study were of 37 weeks' gestation or more and weighed at least 2500 g at birth. Five-minute Apgar scores of 0 and neonatal seizures or serious neurologic dysfunction were analyzed according to where the births took place and whether the delivery was performed by a hospital midwife, a freestanding birth center midwife, a home midwife, or a hospital physician.

Researchers found a relative risk (RR) of 10.55 (95% confidence interval [CI], 8.62 - 12.93) for an Apgar score of 0 for midwife-attended home births (98/60,296 births), compared with the risk during hospital physician delivery (1943/12,615,994 births). The RR for midwife-attended deliveries at freestanding birth centers was 3.56 (95% CI, 2.36 - 5.36; 23/42,000 births). The RR for an Apgar of 0 during hospital midwife delivery was 0.55 (95% CI, 0.45 - 0.68; 95/1,115,794 births), suggesting the critical factor is the location of the birth, not the training of the professional involved in delivery, the authors write.

Risks were greatest for home deliveries of nulliparous patients, with an RR of 14.24 (95% CI, 10.16 - 19.96) for a 5-minute Apgar score of 0 (35/14,801 births) compared with nulliparous patients who had a physician-attended hospital delivery (856/5,155,779 births).

In addition, home births attended by midwives resulted in an RR of 3.80 (95% CI, 2.80 - 5.16) for neonatal seizures or serious neurologic disorders (42/49,091 births) compared with hospital delivery by physicians (1823/8,102,337 births). The RR for freestanding birth centers was 1.88 (95% CI, 1.11 - 3.17; 14/33,188 births). For hospital midwifes, the RR was 0.74 (95% CI, 0.62 9 0.89; 121/727,395 births) compared with physicians.

The authors state that risks determined by this study may be underestimates because some of the bad outcomes marked in the hospital column resulted from transfers to the hospital from a home birth.

"The magnitude of risk associated with home delivery is alarming," Dr. Grünebaum said in a news release from New York–Presbyterian/Weill Cornell Medical Center. The findings, he said, mean caregivers must warn patients of the risks attendant in home birth. "Physicians therefore should not offer and should recommend against birth settings outside the hospital," the authors write.

The key problem is a lack of available resources to deal with emergencies during a home birth, Frank Chervenak, MD, a study coauthor and director of maternal-fetal medicine at New York–Presbyterian/Weill Cornell, said in the release. "[T]here can be unpredictable complications requiring immediate surgical intervention. If an emergency occurs at home that requires hospital transport, it's often difficult to beat the clock to prevent death or neurological issues."

The study contradicts claims that home deliveries have a low risk profile, as a 2012 National Center for Health Statistics Data Brief stated. The data brief based its conclusions on a lower number of preterm births among home deliveries and a lower percentage of low birth-weight infants. It also counted the reduced numbers of teenaged births and reduced deliveries of multiples at home. However, the current study concluded that the risk is higher even after excluding early deliveries, low-birth infants, and multiple deliveries.

The study also contrasts with a Dutch study published in June that looked at maternal morbidity. That research, published in BMJ, involved some 147,000 low-risk women. It found a risk for maternal morbidity of 1 per 1000 among parous women, for an adjusted odds ratio of 0.43. The odds ratio was adjusted for maternal age, gestational age, socioeconomic status, and ethnicity (Dutch or non-Dutch).

The authors have disclosed no relevant financial relationships.

Am J Obstet Gynecol. Published online June 21, 2013. Abstract