Pregnancy: genetics, conception, fetal development Lectures 10 N.Petrenko, MD, PhD.

Pregnancy: genetics, Pregnancy: genetics, conception, fetal conception, fetal

developmentdevelopment

Lectures 10Lectures 10N.Petrenko, MD, PhDN.Petrenko, MD, PhD

Cell Division. MitosisCell Division. Mitosis

Cell Division. Mitosis vs Cell Division. Mitosis vs MeiosisMeiosis

Gametogenesis: SpermatogenesisGametogenesis: Spermatogenesis

GametogenesisGametogenesis

Spermatogenesis primary spermatocytes (46)

2 haploid secondary spermatocyte(22X+22Y)

4 Spermatids

Gametogenesis:Gametogenesis: Oogenesis Oogenesis

Gametogenesis: Spermatogenesis vs Gametogenesis: Spermatogenesis vs OogenesisOogenesis

OvumOvum

SpermSperm

FertilizationFertilization

FertilizationFertilization

FertilizationFertilization

ImplantationImplantation

ImplantationImplantation

Early Developmental StagesEarly Developmental StagesPrimary Germ LayersPrimary Germ Layers

Ectoderm, Mesoderm and Endoderm

During gastrulation, three major cell lineages are being established. They are the Ectoderm (shown in the diagram as blue), Mesoderm (red) and Endoderm (yellow). Following gastrulation, various cell lineages are derrived from these three primary cell types. For example, the Ectoderm gives rise to the epidermis and its derrivatives such as nails, hair and teeth. On the other hand, the Ectoderm also gives rise to the Central Nervous System.

Development of the embrioDevelopment of the embrio

MembranesMembranes

Umbilical cordUmbilical cord

Placenta. Placenta. StructureStructure

Extraembryonic Membranes & Placenta FormationExtraembryonic Membranes & Placenta Formation

Figure 29–5 (1 of 3)

G. Fetus at 2-3weeksG. Fetus at 2-3weeks

I. The Fetus at 5 weeksI. The Fetus at 5 weeks

K. The Fetus at 7 weeksK. The Fetus at 7 weeks

L. Fetus at 8-9 weeks oldL. Fetus at 8-9 weeks old

12 WEEKS(3 months)12 WEEKS(3 months)

14 WEEKS (3 1/2 months)14 WEEKS (3 1/2 months)

15-18 WEEKS15-18 WEEKS ( 4-4 1/2 months)( 4-4 1/2 months)

WEEK 22 (2 1/2 months)WEEK 22 (2 1/2 months)

WEEK 26 WEEK 26 (6 1/2 Months(6 1/2 Months

WEEK 30WEEK 30 (7 1/2 months)(7 1/2 months)

FULL TERM (36 -40 weeks)FULL TERM (36 -40 weeks)

Respiratory Changes During PregnancyRespiratory Changes During Pregnancy

Using the “Wheel”Using the “Wheel”

Expected Physical Changes - Expected Physical Changes - Reproductive SystemReproductive System

Uterine SizingUterine Sizing

Accuracy of Dating by Accuracy of Dating by UltrasoundUltrasound

Gestational Age weeks)

Ultrasound Measurements

Range of Accuracy

< 8 Sac size + 10 days

8-12 CRL + 7 days

12-15 CRL, BPD + 14 days

15-20 BPD, HC, FL, AC + 10 days

20-28 BPD, HC, FL, AC + 2 weeks

> 28 BPD, HC, FL, AC + 3 weeks

Bones and Joints of the Bones and Joints of the PelvisPelvis

The Diagonal ConjugateThe Diagonal Conjugate

The Ischial SpinesThe Ischial Spines

The Pelvic OutletThe Pelvic Outlet

Leopold's ManeuversLeopold's Maneuvers - - are used to determine are used to determine the orientation of the fetus through abdominal the orientation of the fetus through abdominal

palpation.palpation. 1. Using two

hands and compressing the maternal abdomen, a sense of fetal direction is obtained (vertical or transverse).

.

2. The sides of the uterus are palpated to 2. The sides of the uterus are palpated to determine the position of the fetal back and small determine the position of the fetal back and small parts.parts.

3. The presenting part (head or butt) is palpated 3. The presenting part (head or butt) is palpated above the symphysis and degree of engagement above the symphysis and degree of engagement determineddetermined

4. The fetal occipital prominence is 4. The fetal occipital prominence is determined.determined.