Morbi-mortalidade neonatal é maior nos partos em casa?

Lembram-se DESTE estudo que diz que "o risco de morte neonatal no parto em casa aumentou para o dobro em relação ao parto no hospital"

Recebi este mail do Drº Ricardo Jones e partilho com vocês:

"A respeito do trabalho publicado recentemente por médicos americanos, propondo nas conclusões que a morbi-mortalidade neonatal é maior nos partos em casa, eu falei a respeito desta questão com amigos ativistas dos Estados Unidos e Canadá. Entre eles recebi a comunicação do colega Michael Klein, que foi um dos responsáveis pelo recente estudo prospectivo envolvendo parteiras em hospital e domicilio e médicos no hospital na atenção de grávidas de baixo risco (ou risco usual). A carta abaixo foi aceita para publicação no referido jornal.

Esta é a resposta dele:

Klein, MD in Vancouver BC:

The offending article by Wax is already posted on our website. This study is so deeply flawed that it cannot be seen as anything other than politically motivated. Below find the letter that Patti Janssen and I sent to the Am J of Obs and Gyn and which has been accepted for publication.

Michael

American Journal of Obstetrics and Gynecology

Re: Wax J, Pinette M, Cartin A, Blackstone J. Maternal and newborn morbidity by birth facility among selected United States 2006 low-risk births. February 2010, Vol 202, Issue 2 152e1-152e5.

Standards for Validity in Home Birth Research

To the Editors:

The recent paper comparing maternal and newborn morbidity among births at home, hospital and in birth centers by Wax et al, reported that babies born at home more frequently experienced 5 minute Apgar scores below 7.1 The methodology employed brings into question the validity of this conclusion. This retrospective study utilized 2006 US Standard Certificates of Live Birth, used by 19 states in the US. To establish a low obstetrical risk population, multiple exclusions were applied to the data with the result that only 36.0% (745, 690/2,073,368) of women in participating states were included. Inclusion of only slightly more than one third of the potentially eligible population raises questions about the ability of birth certificates to identify women at low risk and consequently the generalizability of study findings.

Secondly, ascertainment of the type of birth attendant is missing for 4801 women or 0.6% of the sample. It is possible that at least some of these births were unattended. If this indeed the case, then these births, which would be expected to have high rates of suboptimal outcomes, might be over-represented in the home birth group, where the attendants are less likely to arrive on time for a precipitous birth. In addition, some women may have deliberately chosen to have an unattended birth and these would of course take place outside of a hospital or birth centre.

Since only 75% of the births studies were recorded as attended by a physician or midwife, fully one quarter may have been unplanned home births. Unplanned home births are well known to be at higher risk for adverse outcomes.

Lastly, the authors acknowledge that births for which complications necessitated transfer to hospital are attributed to hospital rather than to home or birth centre births. In contrast to the above biases, this bias would favor home births. They also acknowledge that perinatal mortality is not measured, which eliminates deaths occurring during labour. In view of these serious flaws, the statement that this study provides a "robust evaluation of maternal and newborn outcomes that is generalizable and reflects actual practice" cannot be supported. Without internal
validity, placed in question by missing data and the inability to attribute births to planned place of birth, the issue of external validity or generalizability is irrelevant.

Recent studies in Canada2,3 and the Netherlands4 have used population-based perinatal databases with mandated participation by midwives and documentation of intended place of birth and attendant, as well as relevant outcomes including intrapartum fetal death. American studies of place of birth must meet this standard in order to draw valid conclusions and allow international comparisons.

1. Wax J, Pinette M, Cartin A, Blackstone D. Maternal and newborn morbidity by birth facility among selected United States 2006 low-risk births. Am J Obstet Gynecol. 2009;202(2):152e151-e155.

2. Janssen P, Saxell L, Page L, Klein M, LIston R, Lee S. Outcomes of planned home birth with registered midwife versus planned hospital birth with midwife or physician. Can Med Assoc J. 2009;181:277-383.

3. Hutton K, Reitsma A, Kaufman K. Outcomes associated with planned home and planned hospital births in low-risk women attended by midwives in Ontario, Canada, 2003-2006: A retrospective cohort study. BIRTH. 2009;36(3):180-189.

4. de Jonge A, van der Goes B, Ravelli A, et al. Perinatal mortality and morbidity in a nationalwide cohort of 529, 688 low-risk planned home and hospital births. BJOG. 2009;116:1177-1184.

Planned Home Births Associated with Tripling of Neonatal Mortality Rate Compared to Planned Hospital Births*

According to New Study Published in the American Journal of Obstetrics & Gynecology

Philadelphia, PA, July 1, 2010 - About 1 in 200 women in the US delivers her baby at home, with approximately 75% of these low-risk, single-baby births planned in advance as home deliveries. In a study published online today by the American Journal of Obstetrics & Gynecology (AJOG), researchers from Maine Medical Center, Portland, Maine, analyzed the results of multiple studies from around the world. They report that less medical intervention, characteristic of planned home births, is associated with a tripling of the neonatal mortality rate compared to planned hospital deliveries. Planned home births were characterized by a greater proportion of deaths attributed to respiratory distress and failed resuscitation.

"Our findings raise the question of a link between the increased neonatal mortality among planned home births and the decreased obstetric intervention in this group," according to lead investigator Joseph R. Wax, MD, Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Maine Medical Center. "Women choosing home birth, particularly low-risk individuals who had given birth previously, are in large part successful inachieving their goal of delivering with less morbidity and medical intervention than experienced during hospital-based childbirth. Of significant concern, these apparent benefits are associated with a doubling of the neonatal mortality rate overall and a near tripling among infants born without congenital defects (nonanomalous). .These findings echoconcerns raised in a recent large US cohort study in which home births experienced significantly more 5-minute Apgar scores <7 as compared to low-risk term hospital births, suggesting an increased need for resuscitation among home births.

Therefore, the personnel, training, and equipment available for neonatal resuscitation represent other possible contributors to the excessive neonatal mortality rate among planned home births."

Investigators conducted a rigorous metaanalysis through which the peer-reviewed medical literature was searched for studies that contained information about home and hospital deliveries, including morbidity and mortality data for both mother and child. They extracted data for a total of 342,056 planned home and 207,551 planned hospital deliveries. The results are striking as women planning home births were of similar and often lower obstetric risk than those planning hospital births.

In contrast to neonatal mortality rates, investigators observed that perinatal mortality rates for planned home and hospital births were similar overall, as well as just among nonanomalous offspring.

Mothers in planned home births experienced significantly fewer medical interventions including epidural analgesia, electronic fetal heart rate monitoring, episiotomy, and operative vaginal and cesarean deliveries. Likewise, women intending home deliveries had fewer infections, perineal and vaginal lacerations, hemorrhages, and retained placentas. Data also showed that planned home births are characterized by less frequent premature and low birthweight infants.

AJOG Editors-in- Chief Thomas J. Garite, MD, and Moon H. Kim, MD, commented that "The report by Wax et al supports the safety of planned home birth for the mother, but raises serious concerns about increased risks of home birth for the newborn infant. This topic deserves more attention from public health officials at state and national levels."

The article is "Maternal and newborn outcomes in planned home birth vs planned hospital births: a metaanalysis" by Joseph R. Wax, MD; F. Lee Lucas, PhD; Maryanne Lamont, MLS; Michael G. Pinette, MD; Angelina Cartin; and Jacquelyn Blackstone, DO. It will appear in the American Journal of Obstetrics & Gynecology, Volume 203, Issue 3 (September 2010) published by Elsevier. DOI: 10.1016/j.ajog.2010.05.028"


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