Waterbirth Fundamentals for Clinicians

Abstract

A related patient education handout can be found at the end of this issue and at www.sharewithwomen.org Waterbirth is defined as fetal emergence underwater and is distinct from immersion hydrotherapy used during labor but not during the actual moment of birth.1 Waterbirth requires maternity providers to expand their knowledge and skills beyond conventional birth care, including research and potential advantages and risks, in order to provide informed consent and to promote safe clinical practice. This issue of the Journal of Midwifery & Women's Health (JMWH) contains an integrative analysis of 38 peer-reviewed studies, which provides an overview of the most current evidence on waterbirth.1 The current state of evidence suggests that the risk of harm from waterbirth to the mother and neonate is minimal. The purpose of this article is to present a combination of general physiologic principles and specific practice recommendations to facilitate safety during waterbirth, as well as clinical pearls to help increase midwives' knowledge of the care modality. FETAL PHYSIOLOGYMidwives who provide waterbirth must understand the basic physiologic theory of fetal breathing movement (FBM) and the fetal dive reflex in order to answer the common question, "Why doesn't the baby drown?" Physiologic theory demonstrates that fetuses are subject to hormonal conditions during physiologic childbirth, which suppress FBM that normally occurs during late gestation and does not typically result in the intake of amniotic fluid into the lungs. Research suggests that the adaptive mildly hypoxic fetal environment during labor further inhibits FBM.2 This is reinforced by endorphins produced during labor by women who do not receive pharmacologic pain relief methods.2 These factors combine to make the risk of water aspiration related to FBM unlikely in healthy fetuses born underwater after uncomplicated parturition.The fetal dive reflex can also serve as a protective mechanism to prevent water aspiration in neonates born in water. The dive reflex is normally present in human newborns and results in obstructive expiratory apnea and closure of the larynx in response to chemoreceptors triggered by foreign substances, including bathwater, near the vocal cords or cold air on the face.2-4 The dive reflex can be overridden during sublethal hypoxia, necessitating appropriate fetal monitoring and the exclusion of compromised fetuses from birth in water in order to minimize the risk of water inhalation.

A Model Practice Template for Hydrotherapy in Labor and Birth

“…23 If a woman desires water immersion and/or waterbirth, the health care provider should engage in an ongoing process of informed consent and shared decision making with the woman regarding this option. 24 The woman and health care provider should discuss the state of the science, risks and benefits of water immersion and waterbirth, and factors that increase the potential for optimal perinatal outcomes; they should review potential barriers to the use of these options based on the woman's unique health history (refer to contraindications outlined in section VIII) and preferences. During the informed consent process, the woman and health care provider should discuss issues that include the limited research that is available about waterbirth; the optimal timing and duration of immersion hydrotherapy; and emerging areas of outcomes research, such as seeding the newborn microbiome after waterbirth and any effect of labor or birth in water beyond the standard perinatal outcomes assessed in studies to date.…”