# Situation: The nurse at a lying-in clinic holds a mothers' class for women between 28 and 36 weeks' gestation whose pregnancies have been uncomplicated. The nurse prepares a chart of fetal development for the class. In what order do these milestones occur, from earliest to latest? 1. Type II alveolar cells begin producing surfactant 2. A first-time mother first feels fetal movement 3. Fingers and toes become separated 4. External genitalia become distinguishable > source: MyMerci (mymerci.kr) > url: https://mymerci.kr/pages/nclex_q.php?qn_id=629473 > language: ko > subject: Nursing Practice II — Maternal and Child Health Nursing ## 문제 Situation: The nurse at a lying-in clinic holds a mothers' class for women between 28 and 36 weeks' gestation whose pregnancies have been uncomplicated. The nurse prepares a chart of fetal development for the class. In what order do these milestones occur, from earliest to latest? 1. Type II alveolar cells begin producing surfactant 2. A first-time mother first feels fetal movement 3. Fingers and toes become separated 4. External genitalia become distinguishable ## 보기 1. 4, 3, 2, 1 2. 3, 2, 4, 1 3. 3, 4, 1, 2 4. 3, 4, 2, 1 **✔ 정답** **정답: 4** ## 해설 By gestational age, fingers and toes are separated by about 10 weeks (end of the embryonic period), external genitalia are distinguishable at about 12 weeks, a primigravida usually feels quickening at 18–20 weeks, and type II alveolar cells begin producing surfactant at about 22–24 weeks. ## 심화 해설 Fetal Development Milestones: Chronological Order The question asks for the correct sequence of four developmental milestones during gestation. The key to answering this type of item is to anchor each event to its approximate gestational age and then arrange them from earliest to latest. The earliest event in this list is the separation of fingers and toes. During the embryonic period, the upper and lower limb buds form and undergo rapid differentiation. The apical ectodermal ridge directs outgrowth, and programmed cell death in the interdigital spaces creates distinct digits. By approximately 10 weeks of gestation, the fingers and toes are fully separated. This marks the end of the embryonic period and the beginning of the fetal period. The next milestone is the ability to distinguish external genitalia. Although genetic sex is determined at fertilization, the external genitalia remain undifferentiated until the influence of hormones—particularly androgens in the male fetus—drives morphological change. By about 12 weeks, the external genitalia have developed enough that male and female structures can be visually differentiated on ultrasound. This is a common point of inquiry in prenatal education and ultrasound interpretation. Following this is quickening, the first perception of fetal movement by the mother. A multigravida may recognize these sensations earlier because she is familiar with the feeling, but a primigravida typically first feels fetal movement between 18 and 20 weeks of gestation. This timing reflects both fetal neuromuscular maturation and the mother's ability to interpret subtle flutter-like sensations in the lower abdomen. The latest milestone in this sequence is the onset of surfactant production by type II alveolar cells. The pulmonary system is one of the last to mature functionally. Type II pneumocytes begin synthesizing and storing surfactant around 22 to 24 weeks, but production does not reach sufficient levels for adequate gas exchange until approximately 35 weeks. This is why prematurity before this window places the neonate at high risk for respiratory distress syndrome. Key point! The correct order is: fingers and toes separated (10 weeks), external genitalia distinguishable (12 weeks), quickening in a primigravida (18–20 weeks), and surfactant production begins (22–24 weeks). This corresponds to option 4: 3, 4, 2, 1. | Milestone | Approximate Gestational Age | Clinical Relevance | | --- | --- | --- | | Fingers and toes separated | 10 weeks | End of embryonic period; major structural anomalies arise before this point | | External genitalia distinguishable | 12 weeks | Sex can often be identified on ultrasound; timing of genital differentiation | | Quickening (primigravida) | 18–20 weeks | First maternal perception of fetal movement; used to confirm ongoing pregnancy | | Type II alveolar cells produce surfactant | 22–24 weeks | Marks the lower limit of potential extrauterine viability; surfactant deficiency causes RDS | Watch out! Do not confuse the onset of surfactant production (22–24 weeks) with the time when surfactant levels are adequate for postnatal lung function (around 35 weeks). The question asks when production begins, not when it becomes sufficient. The provided reference materials focus on cerebral palsy diagnostic criteria, cleidocranial dysplasia management, a SPAST gene variant case, and brain age modeling in prematurity and congenital heart disease. These sources do not directly address the timing of fetal developmental milestones such as digit separation, genital differentiation, quickening, or surfactant production. Therefore, the explanation above is based on standard embryology and obstetric nursing knowledge consistent with the correct answer and the core conclusion of the provided rationale. ## 임상 시나리오 Antenatal Teaching: Fetal Milestone TimelineSequencing key developmental events for expectant mothers Teach parents that digit separation completes by 10 weeks, marking the end of the embryonic period. External genitalia become distinguishable on ultrasound around 12 weeks, which is often when fetal sex may be discussed. A primigravida typically first feels quickening between 18 and 20 weeks; multigravidas may notice it earlier. Type II alveolar cells begin producing surfactant at 22-24 weeks, a critical threshold for extrauterine viability and lung maturity. CautionWhen teaching mothers at 28-36 weeks, emphasize that surfactant production is ongoing and may be insufficient if preterm birth occurs before 34 weeks without antenatal corticosteroid administration. ## 핵심 개념 - **Quickening** — The first maternal perception of fetal movement, typically felt by a primigravida between 18 and 20 weeks of gestation. - **Type II Alveolar Cells** — Specialized cells in the fetal lungs that begin producing pulmonary surfactant at approximately 22-24 weeks of gestation, which is crucial for alveolar stability after birth. - **Embryonic Period** — The period of gestation from fertilization through the 8th week, characterized by major organogenesis and structural differentiation, ending when fingers and toes separate around 10 weeks. - **External Genitalia Differentiation** — The process by which undifferentiated external genitalia develop into recognizable male or female structures, visually distinguishable by ultrasound at about 12 weeks of gestation. ## 같은 주제 문제 - [Situation: A 26-year-old woman comes to the Rural Health Unit (RHU) for her first prenatal…](https://mymerci.kr/pages/nclex_q.php?qn_id=629366) - [Situation: A 26-year-old woman comes to the Rural Health Unit (RHU) for her first prenatal…](https://mymerci.kr/pages/nclex_q.php?qn_id=629367) - [Situation: A 26-year-old woman comes to the Rural Health Unit (RHU) for her first prenatal…](https://mymerci.kr/pages/nclex_q.php?qn_id=629368) - [Situation: A 26-year-old woman comes to the Rural Health Unit (RHU) for her first prenatal…](https://mymerci.kr/pages/nclex_q.php?qn_id=629369) - [Situation: A 30-year-old primigravida at 30 weeks' gestation attends a prenatal check-up a…](https://mymerci.kr/pages/nclex_q.php?qn_id=629370) - [Situation: A 30-year-old primigravida at 30 weeks' gestation attends a prenatal check-up a…](https://mymerci.kr/pages/nclex_q.php?qn_id=629371) - [Situation: A 30-year-old primigravida at 30 weeks' gestation attends a prenatal check-up a…](https://mymerci.kr/pages/nclex_q.php?qn_id=629372) - [Situation: A 30-year-old primigravida at 30 weeks' gestation attends a prenatal check-up a…](https://mymerci.kr/pages/nclex_q.php?qn_id=629373) --- More free questions: [기출문제](https://mymerci.kr/) _학습 참고용입니다. 실제 임상은 최신 지침과 소속 기관 프로토콜을 따르세요._