In modern obstetrics, the clinical use of trimesters to describe a speciic pregnancy is imprecise. For example, it is inappropriate in cases of uterine hemorrhage to categorize the problem temporally as "third-trimester bleeding." Appropriate management for the mother and her fetus will vary remark ably depending on whether bleeding begins early or late in the third trimester (Chap. 41, p. 757). Because precise knowledge of fetal age is imperative for ideal obstetrical management, the clinically appropriate unit is weeks of gestation complete. And more recently, clinicians designate gestational age using com pleted weeks and days, for example, 334/7 weeks or 33 + 4, for 33 completed weeks and 4 days.
As elsewhere in medicine, history taking begins with queries concerning medical or surgical disorders. Also, detailed information regarding previous pregnancies is essential as many obstetrical complications tend to recur in subsequent pregnancies. The menstrual and contraceptive histories are also important. Gestational or menstrual age is the number of weeks since the onset of the last menstrual period in women with menstrual cycles lasting 28 to 30 days. For those with irregular menses, sonography in early pregnancy will clariy gestational age. Last, some methods of birth control favor ectopic implantation following method failure (Chap. 38, pp. 683 and 689).
Psychosocial Screening. The American Academy of Pediatrics and the American College of Obstetricians and Gynecologists (2017) define psychosocial issues as nonbiomedical factors that afect mental and physical well-being. Women should be screened regardless of social status, education level, race, or ethnicity. Such screening should seek barriers to care, communication obstacles, nutritional status, unstable housing, desire for pregnancy, safety concerns that include intimate-partner violence, depression, stress, and use of substances such as tobacco, alcohol, and illicit drugs. his screening is performed on a regular basis, at least once per trimester, to identiy important issues and reduce adverse pregnancy outcomes. Coker and colleagues (2012) compared pregnancy outcomes in women before and after implementation of a universal psychosocial screening program and found that screened women were less likely to have preterm or low-birthweight newborns, as well as other adverse outcomes. Speciic screens for depression are presented in Chapter 61 (p. 1174).
Cigarette Smoking. Data on this practice have been included on the birth certiicate since 1989. The number of pregnant women who smoke continues to decline. From 2000 to 2010, the prevalences were 12 to 13 percent (Tong, 2013). Based on the Pregnancy Risk Assessment Monitoring System, these women were more likely younger, had less education, and were either Alaska Natives or American Indians (Centers for Disease Control and Prevention, 20 13a).
Numerous adverse outcomes have been linked to smoking during pregnancy (U.S. Department of Health and Human Services, 2000). Potential teratogenic efects are reviewed in
TABLE 9-2. Five A's of Smoking Cessation
ASK about smoking at the first and subsequent prenatal visits.
ADVISE with clear, strong statements that explain the risks of continued smoking to the woman, fetus, and newborn. ASSESS the patient's willingness to attempt cessation. ASSIST with pregnancy-specific, self-help smoking cessation materials. Ofer a direct referral to the smoker's quit line (1-800-QUIT NOW) to provide ongoing counseling and support. ARRANGE to track smoking progress at subsequent visits.
Adapted from Fiore, 2008.