Chapter 43 Stephanie A. Crapo Pregnancy is commonly encountered in the prehospital setting, and its management typically requires little more than a focused history and physical examination along with safe and timely transport to an appropriate hospital. There are notable exceptions, such as imminent delivery, that have the potential to be catastrophic. These are stressful, time-sensitive emergencies. Gravidity is the number of times a woman has been pregnant and parity is the number of times a woman has given birth to a fetus of 20 weeks or more, regardless of whether the fetus was alive or stillborn. Neither gravidity nor parity is increased for twin pregnancies. For example, a woman who has one twin pregnancy with successful delivery of both infants is denoted G1P1. Ovulation occurs around day 14 of the menstrual cycle. The egg is fertilized usually in the oviduct and migrates through the fallopian tubes into the uterus. The egg implants in the uterus around day 6 following fertilization. The heartbeat is first detected by ultrasound in weeks 8–12. The first fetal movements are felt in weeks 18–20 for a primigravid patient and 2 weeks earlier in the multiparous patient [1]. A full pregnancy lasts approximately 40 weeks. It is divided into trimesters and usually measured by weeks. The first trimester is weeks 0–13, the second trimester is weeks 14–27, and the third trimester is weeks 28–42. A pregnancy is considered viable between 22 and 26 weeks [2]. Term pregnancy is carried to at least 37 weeks. Gestational age can be estimated by both last menstrual period and fundal height. Nine months and 7 days are added to the first day of the last menstrual period (Nagele rule) to obtain the estimated due date. Calculation from the last menstrual period usually overestimates gestational age. Fundal height is a rapid clinical tool to estimate gestational age. It is measured in centimeters from the pubic symphysis to the top of the fundus. Centimeters = weeks of gestation +/- 2 weeks. Using this estimation, a 20-week pregnancy reaches the umbilicus. Many physiological changes occur in pregnancy induced both by hormones and/or by the enlarging uterus (Box 43.1) [1]. All levels of EMS providers, from first responders to physicians, should be capable of rapidly ascertaining pertinent information from the ill or injured pregnant patient. In addition to questions relating to the chief complaint, an obstetrical and gynecological history is important to elicit, including last menstrual period, contraceptive use, gravidity, and parity. Providers should be expected to expand that history and determine if the patient has had complications associated with the current pregnancy such as gestational diabetes, preeclampsia, or preterm labor or if the patient has had complications with prior pregnancies. If delivery is imminent, history should include frequency and strength of contractions, and fluid/water leakage. As soon as it is determined that the patient is not going to deliver imminently, vital signs should be obtained and viewed in context of the normal physiological changes of pregnancy. Examination includes thorough evaluation of the mother as well as the fetal status. If the patient has signs of active labor such as contractions, urge to defecate or push, rupture of membranes, or any other concerning signs, a visual examination of the perineum should be performed. Medical directors should carefully craft protocols that specify when visual inspection of the perineum is appropriate. Failure to have a written document for the EMS provider to follow opens the provider, medical director, and system to potential liability. Many prehospital providers are including ultrasound in the evaluation of patients (see Volume 1, Chapter 69). Ultrasound is especially useful in the evaluation of pregnant patients to confirm intrauterine pregnancy as well as to evaluate fetal well-being with heartbeat and fetal movement. The earliest definitive sonographic finding in pregnancy is the gestational sac, detected at 6–8 weeks on transabdominal ultrasound [1,3]. Later in pregnancy, fetal viability can be assessed by observing fetal movement and fetal heart tones. Fetal heart tones should be 120–160 beats per minute after 12 weeks’ gestation. They are first detected on ultrasound around 8 weeks’ gestation but it may be up to 12 weeks before heart tones are seen, depending on the habitus of the patient and quality of ultrasound used [3]. A major concern in pregnant patients with abdominal pain is ectopic pregnancy. While it is not expected to be diagnosed in the field, ultrasound can assist in the recognition of ectopic pregnancy. An intrauterine pregnancy visible on ultrasound essentially excludes ectopic pregnancy. Some ultrasound findings suspicious for ectopic pregnancy include pelvic free fluid and adnexal mass other than simple cyst. A gestational sac, yolk sac, or fetal pole with heartbeat outside the uterus confirms the diagnosis of ectopic pregnancy [3]. Labor is “the presence of uterine contractions of sufficient frequency, duration, and intensity to cause demonstrable effacement and dilation of the cervix [4].” Active labor is divided into three stages [5] (Box 43.2
Normal childbirth
Introduction
Pregnancy
Definitions
Gestational age
Physiological changes of pregnancy
Evaluation of the pregnant patient
Ultrasound in pregnancy
Labor and delivery
Active labor
Related posts:
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
