Skip to main content
Ch. 28 Pregnancy and Human Development
Hoehn - Marieb Human Anatomy & Physiology, 12th edition
Hoehn, Haynes, Abbott12th EditionMarieb Human Anatomy & PhysiologyISBN: 9780138242732Not the one you use?Change textbook
Chapter 28, Problem 25

Claire is a heavy smoker and has ignored a friend’s advice to stop smoking during her pregnancy. On the basis of what you know about the effect of smoking on physiology, describe how Claire’s smoking might affect her fetus.

Verified step by step guidance
1
Understand that smoking introduces harmful substances such as nicotine, carbon monoxide, and tar into the mother's bloodstream, which can cross the placenta and affect the fetus.
Recognize that nicotine causes vasoconstriction, which reduces blood flow in the placenta, thereby limiting oxygen and nutrient delivery to the fetus.
Consider that carbon monoxide binds to hemoglobin more effectively than oxygen, reducing the oxygen-carrying capacity of the mother's blood and leading to fetal hypoxia (low oxygen levels).
Acknowledge that reduced oxygen and nutrient supply can impair fetal growth and development, potentially causing low birth weight, premature birth, or developmental abnormalities.
Note that smoking during pregnancy increases the risk of complications such as placental abruption, miscarriage, and long-term health issues for the child, including respiratory problems and increased susceptibility to infections.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Effects of Smoking on Oxygen Transport

Smoking introduces carbon monoxide into the bloodstream, which binds to hemoglobin more readily than oxygen, reducing oxygen delivery to tissues. In pregnancy, this limits oxygen supply to the fetus, potentially causing hypoxia and impairing fetal development.
Recommended video:
1:32
Effects of the Complement System

Impact of Nicotine on Fetal Development

Nicotine constricts blood vessels, including those in the placenta, reducing blood flow and nutrient delivery to the fetus. This can lead to low birth weight, developmental delays, and increased risk of complications during pregnancy.
Recommended video:
5:24
Extraembryonic Membrane Development (Weeks 2-8)

Teratogenic Effects of Smoking

Chemicals in cigarette smoke act as teratogens, substances that can cause birth defects or developmental abnormalities. Exposure during pregnancy increases risks of miscarriage, premature birth, and congenital malformations.
Recommended video:
1:32
Effects of the Complement System
Related Practice